Recent advances in virus imprinted polymers

10 (2022) 100131 A ailable online 23 Ma ch 2022 2590-1370/© 2022 The Au ho s. Published by Else ie B.V. This is an open access a icle unde he CC BY-NC-ND license (h p://c ea i ecommons.o g/licenses/by- nc-nd/4.0/). Recen ad ances in i us imp in ed polyme s Ma iana S. Amo im, M. Go e i F. Sales ** , Manuela F. F asco * BioMa k@UC/CEB - LABBELS, Depa men o Chemical Enginee ing, Facul y o Sciences and Technology, Uni e si y o Coimb a, Coimb a, Po ugal ARTICLE INFO Keywo ds: Molecula imp in ing echnology Vi uses Biosenso s Disease de ec ion ABSTRACT Molecula imp in ing is a ma u e and appealing echnology o ob ain highly selec i e ecogni ion si es c ea ed wi hin a polyme ic ne wo k, ha ing o he impo an ea u es such as obus ness and cos e ec i eness. The applica ions o molecula ly imp in ed polyme s (MIPs) a e as , bu he e is a con inuous pa icula in e es in hei in eg a ion in o sensing de ices. MIPs possess ema kable p ope ies in e ms o selec i i y and low-cos o ailo ed biomime ic ecogni ion elemen s. The need o imp o e disease diagnosis and p e en ion by de ec ing pa hogenic i uses and o he biological a ge s a he nanoscale has led o g ea ad ances in MIPs. Despi e s ill acing many challenges, imp in ing app oaches can p o ide apid and accu a e i us ecogni ion and hus be applied as new sensing ma e ials. Following a gene al o e iew o MIP echnology, key examples o i us imp in ed polyme s, he applica ion o MIP-based ma e ials o o he nanoscale a ge s, and hei de ec ion a e p esen ed he e. Pe spec i es and challenges a e also highligh ed o eseeing new u u e s a egies and MIP designs. 1. In oduc ion The abili y o c ea e biomime ic ma e ials co e s se e al ields o esea ch. One o he mos p oli ic examples is he a i icial ligand- binding si es c ea ed wi hin a polyme ic ma ix, known as molecula ly imp in ed polyme s (MIPs). The inspi a ion comes om he na u al molecula in e ac ions esul ing in e y s able binding phenomena ha occu in he biological sys ems. Thus, MIPs a e desc ibed as plas ic an- ibodies, and a e obus and highly selec i e ma e ials. The his o y o MIPs is linked o sepa a ion p ocesses, i.e., he necessi y o en ichmen o ex ac ion o small molecules (G ebe and Fla , 2019). None heless, he use o his echnology has apidly e ol ed and is used o he de ec ion o a ange o molecules, om small o la ge a ge s (Re aa e al., 2019). No su p isingly, MIPs ha e now been success ully applied o la ge and complex i uses, bac e ia, and cells (Liu e al., 2020; Ren and Za e, 2012). Rega ding i uses, he challenges posed by ecu en ou b eaks o pa hogenic i uses, and hei impac on heal h and he economy, make hem appealing a ge s o con inuous imp o emen o de ec ion me hods. In his e iew, a gene al o e iew o he MIP echnology is i s ou lined o hen highligh he mos signi ican examples o MIP-based ma e ials de eloped o ecognize i uses and biological a ge s a he nanoscale. MIPs de eloped using whole o in ac i uses can be mo e challenging, bu a he same ime o e g ea e insigh on he syne gy be ween he es ablished mul iple in e ac ions and he shape- complemen a y ca i ies. Thus, i us imp in ed polyme s will be he ocus o his e iew, hoping he examples o biomime ic ma e ials p e- sen ed will inspi e he de elopmen o new s a egies and MIP designs. 2. Molecula imp in ing echnology MIPs a e ailo -made syn he ic ma e ials wi h a i icially c ea ed ecogni ion si es ha a e able o selec i e ebind a a ge compound, ins ead o closely ela ed compounds (Tu iel and Es eban, 2019). MIPs a e gene a ed by polyme izing unc ional and c osslinking monome s a ound a empla e molecule, hus ob aining a c osslinked h ee-dimensional ne wo k polyme (Tu iel and Es eban, 2019). Compa ed o o he ecogni ion sys ems, MIPs possess h ee majo unique ea u es: s uc u e eliabili y, ecogni ion speci ici y and uni- e sal applica ion. Thus, hei use is e y signi ican in many ields, anging om pu i ica ion and sepa a ion, ca alysis, chemo/biosensing, and d ug deli e y. The ea u es o MIPs ega ding high chemical and physical s abili y, s aigh o wa d p epa a ion, ema kable obus ness and low-cos a e e y a ac i e in hese esea ch ields (Ca doso e al., 2018; Chen e al., 2016). Among he many applica ions, he in eg a ion o MIPs in o biosenso s is one o he mos c ea i e due o he need o * Co esponding au ho . ** Co esponding au ho . E-mail add esses: [email p o ec ed], [email p o ec ed] (M.G.F. Sales), [email p o ec ed] (M.F. F asco). Con en s lis s a ailable a ScienceDi ec Biosenso s and Bioelec onics: X jou nal homepage: www.jou nals.else ie .com/biosenso s-and-bioelec onics-x h ps://doi.o g/10.1016/j.biosx.2022.100131 Recei ed 31 Decembe 2021; Recei ed in e ised o m 15 Ma ch 2022; Accep ed 18 Ma ch 2022 Biosenso s and Bioelec onics: X 10 (2022) 100131 2 imp o e he selec i i y and sensi i i y o de ec ion o diagnos ic me hods h ough cos -e ec i e and obus biomime ic s a egies (Fig. 1). 2.1. MIP componen s The e ec i eness, a ini y, and selec i i y o he ecogni ion si es o a MIP a e g ea ly in luenced by i s componen s ( empla e, monome s, c osslinke , polyme iza ion ini ia o and sol en ) and by he quali y o he in e ac ions be ween hem. Thus, when designing he MIP, he se- lec ion o i s componen s is a c i ical s ep o achie e he desi ed p op- e ies o a ce ain applica ion (Su yana e al., 2021; Tu iel and Es eban, 2019). Fi s , i is c ucial o conside he molecula s uc u e o he empla e ha will de e mine he choice o he unc ional monome (s). The s uc u e and he numbe o binding si es in he imp in ed polyme , i.e., he molecula ecogni ion, depends on he chemical bonds es ablished be ween hem. Fo his eason, he empla e and unc ional monome (s) mus complemen each o he o maximize he imp in ing p ocess (Co - mack and Elo za, 2004; Su yana e al., 2021). Mo eo e , he empla e should no possess unc ionali ies esponsible o po en ially inhibi ing o e a ding he polyme iza ion and should be s able unde he syn hesis condi ions (Co mack and Elo za, 2004). The c osslinke has also o be conside ed as a undamen al elemen o a MIP. Se e al c ucial s eps depend on a p ope c osslinking o he polyme , such as: (a) o ma ion o he imp in ed pocke by eezing he empla e-monome complex upon polyme iza ion; (b) s abilizing he imp in ing binding si e; (c) ensu ing polyme mechanical s abili y; (d) con olling he mo phology o he polyme ma ix. Thus, he eac i i y o he c osslinke and he a io monome o c osslinke a e e y impo an o ob ain unc ionalized si es ha a e sp ead uni o mly h oughou he polyme ic ne wo k and o ha e p ope ly spaced ca i ies wi h no cons ains o he di usion o he empla e (Be gmann and Peppas, 2008). The polyme iza ion begins wi h ini ia o s as sou ce o chemical species ha eac wi h he monome s o o m an in e media e compound capable o linking successi ely wi h o he monome s in a chain-g ow h polyme iza ion un il a polyme ic compound is eached. They a e o en he mo-, pho o- o edox-ini ia o s, which ha e been ex ensi ely used in commonly ee adical polyme iza ions. The sol en is he medium whe e he polyme iza ion occu s and i s molecules occupy space in he polyme ic ma ix, hus c ea ing po es and being named as po ogen. In his sense, he na u e and olume o he sol en is also impo an o de elop a o able po es in he ma ix ha will con ibu e o a p ope di usion o he empla e ou o he ne wo k and i s subsequen di usion back in o he polyme du ing ecogni ion (Be gmann and Peppas, 2008; Vasapollo e al., 2011). 2.2. MIP syn hesis and p epa a i e app oaches The s uc u e o he polyme ma ix is mac opo ous wi h nano- ca i ies complemen a y o ha o he empla e molecule (Włoch and Da a, 2019). To achie e his o ganized ne wo k, he molecula imp in ing p ocess has se e al s eps (Fig. 1): (1) dissolu ion o empla e, unc ional monome s, c osslinke , and ini ia o in he sol en ; (2) in e ac ion o he unc ional monome s wi h he empla e molecule, which esul s in he o ma ion o a s able empla e-monome complex; (3) ixing he unc ional monome s posi ioned a ound he empla e by copolyme iza ion wi h c osslinke s; (4) emo al o he empla e Fig. 1. Schema ic ep esen a ion o biosenso s, alongside he scheme o p oducing MIPs. M.S. Amo im e al. Biosenso s and Bioelec onics: X 10 (2022) 100131 3 molecules om he ma ix, o example by ex ac ion wi h a sol en ; (5) he polyme ma ix is le wi h binding si es complemen a y in shape, size and unc ionali ies o he a ge compound (Tu iel and Es eban, 2019). The e o e, he ob ained polyme ma ix ecognizes and binds selec i ely he empla e molecules (Włoch and Da a, 2019). The esul ing imp in ed polyme s a e s able, obus , and esis an o a wide ange o pH, sol en s, and empe a u e. The e o e, he beha iou o MIPs mimics he in e ac ions es ablished by na u al ecep o s o selec i ely e ain a a ge molecule bu wi hou he associa ed s abili y limi a ions. Besides, he syn hesis o MIPs is ela i ely simple and inexpensi e, p o iding a clea al e na i e o he use o na u al ecep o s (Tu iel and Es eban, 2019). Based on he ypes o in e ac ions be ween he a ge molecule and he unc ional monome s, h ee gene al app oaches ha e been desc ibed o he syn hesis o MIPs, namely, co alen , non-co alen , and semi- co alen app oaches. The co alen app oach in ol es he o ma ion o e e sible co alen bonds be ween he empla e molecule and mono- me s be o e polyme iza ion. Then, he empla e is emo ed om he polyme by clea age o he co esponding co alen bonds, which a e e o med upon ebinding o he a ge compound (Tu iel and Es eban, 2019). Since co alen imp in ing is s oichiome ic, unc ional monome esidues exis only in he imp in ed ca i ies. Thus, i minimizes he p esence o nonspeci ic si es due o he high s abili y o empla e-monome in e ac ions (Chen e al., 2016; Tu iel and Es eban, 2019). Howe e , he co alen app oach is less lexible ela ed o limi ed bond o ma ion and clea age eadily e e sible eac ions unde mild condi ions and i is di icul o each he modynamic equilib ium due o slow binding and dissocia ion esul ing om s ong co alen in- e ac ions (Chen e al., 2016; Tu iel and Es eban, 2019). The non-co alen app oach is based on es ablishing non-co alen in- e ac ions be ween he empla e and he monome s, such as hyd ogen bonds, ionic in e ac ions, an de Waals o ces and π − π in e ac ions. Usually, he majo in e ac ion is hyd ogen bonding, and his app oach is by a he mos common because he p epa a ion o MIPs is simple, he e a e many a ailable monome s, and he binding and emo al s eps a e apid (Chen e al., 2016; Tu iel and Es eban, 2019). None heless, he non-co alen imp in ing is less obus because he in e ac ions holding he complex oge he can be mo e easily dis up ed (Chen e al., 2016). An in e media e al e na i e is o combine he s abili y o co alen imp in ing and he as a ge up ake o non-co alen imp in ing, by ollowing a semi-co alen imp in ing (Chen e al., 2016; Tu iel and Es eban, 2019). In his case, he empla e is co alen ly bound o a unc ional monome , bu he ebinding is based only on non-co alen in e ac ions (Chen e al., 2016). The e a e also a a ie y o me hods a ailable o p epa ing he imp in ed polyme s, esul ing in di e en o ma s, and he choice is usually in insic o he inal applica ion. MIPs can be p epa ed as bulk polyme monoli hs, equi ing subsequen mechanical g iding o be ob ained al eady in mic osizes using me hods such as p ecipi a ion and emulsion polyme iza ions o sol-gel p ocesses. O he e y in e es ing app oaches ha e eme ged wi h he possibili y o su ace imp in ing, su ace g a ing, solid-phase syn hesis, click-chemis y, elec o- polyme iza ion, among plen y examples ha can be ound in he li e - a u e (Chen e al., 2016; Re aa e al., 2019; Vanecko a e al., 2020). 3. Applica ions The i s and mos success ul applica ion ield o MIPs is in sepa a ion echnologies. The MIPs a e used as so ben s in solid-phase ex ac ion due o hei s uc u al p edic abili y, he mal and chemical s abili y. These ea u es a e essen ial so ha di e en ypes o composi es can be o med, and hus applied o selec i ely concen a e samples in biolog- ical, pha maceu ical, and en i onmen al ields. This p ocedu e is di ec ly coupled wi h speci ic analy ical sys ems, such as high- pe o mance liquid ch oma og aphy, minimizing sample manipula- ion, educing he loss o analy es, he isk o con amina ion and he ime o p e- ea men o he samples. The aim is o inno a e he solid-phase ex ac ion me hod owa ds ewe s eps, ha ul ima ely lead o simplici y, au oma ion, and minia u iza ion. Addi ionally, when he sample is complex and he p esence o in e e en s may p e en quan- i ica ion by s anda d ch oma og aphic echniques, a cus omized sample ea men s ep can be made wi h his echnology p io o he inal de e mina ion (Gao e al., 2020; Qiao e al., 2006; Tamayo e al., 2007; Vasapollo e al., 2011). Ca alysis is ano he in e es ing esea ch ield wi h many po en ials o MIPs. Enzymes, na u ally and e icien ly, ca alyze a la ge a ie y o chemical eac ions, due o he speci ic in e ac ions in he ac i e si e be ween key amino acid esidues and subs a es. Howe e , he e a e some limi a ions o hei wide applica ions usually connec ed o hei low s abili y in o ganic sol en s, as well as in ex eme empe a u es and pH. Fo his eason, when sea ching o a i icial mimics ha could o e come hese cons ain s, bu a he same ime main ain he expec ed selec i i y and speci ici y p o ided by na u al enzymes, MIPs cons i u e an e icien echnology. Wi h MIPs, i is possible o ob ain polyme s ha display enzyme-like ca aly ic ac i i y by imp in ing analogues o sub- s a es o ansi ion s a es. The e o e, hese syn he ic polyme s a e ce ainly o g ea in e es when de eloping enzyme mimics, elying on hei he mal and chemical s abili y, being easily p oduced o indus ial applica ions. None heless, he posi i e p ope ies o MIPs as ca alys s, migh also ep esen a disad an age. Namely, he igh subs a e binding and he igidi y o he ecogni ion pocke may esul in low eac i i y and p oduc inhibi ion (D amou and Ta annum, 2016; Mi a a and Resmini, 2015; Vasapollo e al., 2011; Wul , 2001). In ecen yea s, he applica ion o MIPs in d ug deli e y sys ems has been g owing apidly. The esea ch on s imuli- esponsi e MIPs and he use o biocompa ible polyme ic ma e ials has many en husias ic Fig. 2. Illus a ion o he nume ous empla es ha ha e been used o de elop MIPs. Copy igh 2020, Rep oduced unde he e ms and condi ions o he C ea i e Commons A ibu ion 4.0 License (El-Schich e al., 2020). M.S. Amo im e al. Biosenso s and Bioelec onics: X 10 (2022) 100131 4 p ospec s in hyb id biomedical in i o app oaches (Chen e al., 2015; El-Schich e al., 2020; Haup , 2001; Iskie ko e al., 2016; Saylan e al., 2017; Xu e al., 2011). The memo y nanoca i ies ha could be loaded wi h a my iad o molecula compounds and be o -loaded h ough a ious ou es o adminis a ion (e.g., ocula , de mal, in a enous, e c.) ha e eno mous po en ial bo h o imaging and he apy (Vanecko a e al., 2020). MIP-based biosenso s, o sensi i e, apid, low-cos poin -o -ca e diagnos ics, is also a huge ield o in e es , as MIPs can be combined wi h se e al di e en ansduce app oaches in a wide a ie y o senso pla o ms. Biosenso s combine a bio- ecogni ion elemen wi h a signal p ocesso and a sui able ansduce app oach, which can be o elec o- chemical, mass, o op ical na u e, among many o he s, o de ec ing subs ances and moni o ing biological in e ac ions (Fig. 1) (Ca doso e al., 2018; Chen e al., 2020). The bio-based ecogni ion elemen in- cludes a cap u e compound ha binds o/in e ac selec i ely wi h he a ge analy e. In his sense, MIPs can be used as excellen ecogni ion elemen s due o hei high selec i i y, sensi i i y, long- e m s abili y, and chemical ine ness (Vasapollo e al., 2011). 4. Vi us imp in ed polyme s In ec ious diseases widely dissemina ed by pa hogenic mic oo gan- isms, namely i uses, a e o pa icula conce n. Howe e , despi e huge p og ess in diagnos ics, ea men and p e en ion, hese diseases a e s ill a se ious global heal h isk. Fo his eason, ea ly diagnosis o i uses is essen ial o clinical and poin -o -ca e applica ions. The ools used o de ec ion o i uses a e mainly based on enzyme-linked immunoso ben assay and polyme ase chain eac ion (PCR) ampli ica ion (Boonham e al., 2014). These me hods a e ecognized by hei high sensi i i y, bu hey a e s ill ime-consuming, wi h high p oduc ion cos s, and equi e ope a ion by a specialis (Boonham e al., 2014; Cui e al., 2020). Molecula imp in ing can be applied o a wide ange o a ge mol- ecules, which is one o he many a ac i e ea u es o his echnique (Fig. 2). The imp in ing o low molecula weigh compounds as a ge analy es is well es ablished and highly success ul. When i comes o p epa e selec i e ecogni ion ecep o s o la ge biological a ge s, using mac omolecula empla es, he e a e inhe en challenges such as: (a) he bulkiness o he empla e molecules is connec ed o slow di u- sion o he molecula ca i ies, making he esponse o he MIP senso undesi ably long; (b) cha ged unc ional monome s may be less e icien in he imp in ing o high molecula weigh compounds; (c) he s ep o empla e emo al is ha de , as i canno be emo ed smoo hly om he imp in ed ca i ies, hus lowe ing he deso p ion e iciency o he em- pla e (El-Schich e al., 2020; Haup , 2001; Iskie ko e al., 2016; Saylan e al., 2017). These di icul ies a e some imes su passed by epi ope imp in ing, i. e., a small agmen o he mac omolecule is imp in ed aiming o c ea e s onge in e ac ions. None heless, his app oach also has in insic lim- i a ions ha may lead o less speci ic in e ac ions, e.g., unsui able se- lec ion o epi ope leng h and s uc u e (Die l e al., 2021; Zhang e al., 2021). A emp ing o g asp he complexi y o mac omolecules in a polyme ic image o he whole, p ese ed in he imp in ed subs a es, can be pa icula ly ele an o imp o e he ecogni ion o i us and o he biological a ge s wi h sizes a he nanoscale. Pa icula ly o he de ec ion o in ac i uses, he applica ion o MIPs can ul ima ely be a way o o e come he limi a ions o cu en me hodology, and in e es in his ield o esea ch has been h i ing (A zal e al., 2017; Al in as, 2016; Cui e al., 2020; Jamalipou Sou i e al., 2021). In e es ing examples o MIPs de eloped by empla ing whole i uses and in eg a ion o hose ma e ials wi hin di e se ans- duce schemes a e discussed in he ollowing sec ions. 4.1. Tobacco mosaic i us Tobacco mosaic i us (TMV) is he i s obse ed and epo ed i us disease, which has been well-s udied and cha ac e ized. This i us has he po en ial o damage he lea es o di e en plan s, pa icula ly o- bacco, being esponsible o obacco mosaic. TMV is s able in a ious condi ions o pH, empe a u e, sol en s, and educing agen s. The TMV i ion is a odlike i us wi h a leng h o 300 nm and diame e o 18 nm, composed o 2130 p o ein subuni s ha o m a helical s uc u e (Hema e al., 2019; Soui i e al., 2019). The e a e se e al wo ks o TMV de ec ion based on di e en imp in ing me hods. Fo example, a MIP app oach elied on p oducing a lexible non-co alen TMV imp in ed polyme hyd ogel o polyallyl- amine c osslinked wi h e hylene glycol diglycidyl e he using TMV as empla e (Bolisay and Ko inas, 2010). None heless, mos s udies ound in he li e a u e a e based on su ace imp in ing. One MIP has been in- eg a ed on a mic o luidic biochip and he de ec ion elied on con ac -less bioimpedance spec oscopy (Bi nbaume e al., 2009). The MIP was assembled by su ace imp in ing using a i us s amp ha was p essed in o a co-polyme o me hac ylic acid and N- inylpy olidone, spin-coa ed on he de ice. One o he ad an ages o combining mic o- luidics wi h he MIP had o do wi h he p ecise con ol o e luid dy- namic shea o ces. Thus, i was possible o s udy i al binding a ini y and dissocia ion kine ics, and he de eloped chip p esen ed as esponse imes and eusabili y (Bi nbaume e al., 2009). In e es ingly, such s amping echnique has been explo ed in o he wo ks oge he wi h mass-sensi i e measu emen s using qua z c ys al mic obalances (QCM) (Dicke e al., 2003, 2004, 2003; Hayden e al., 2003, 2006). In such s amping me hod, he s amp and he polyme coa ing a e p epa ed sepa a ely, and he inal ma e ial is ob ained by mechanically p essing he wo subs a es oge he (Hayden e al., 2006). TMV was success ully s amped on p e-polyme ized mix u es o me hac ylic acid, s y ene and di inylbenzene, ollowed by UV cu ing and emo al o i uses. The ca i ies on he imp in ed polyme su ace ecognized he i us and he senso e ec s we e obse ed on QCM (Dicke e al., 2003). The esul ing sensi i e laye con aining he su ace pa e ning was gene a ed di ec ly on gold elec odes. Using his ype o senso s and polyme s based on ac ylic acid and e hylene glycol dime hac yla e (EGDMA), TMV could be de ec ed in a ange o concen a ions om 100 ng mL −1 o 1 mg mL −1 , wi hin minu es (Dicke e al., 2004). When pho o- imp in ing TMV on he su ace o an azopolyme , he immobiliza ion a e pho oi adi ion was s udied by a omic o ce mic oscopy (AFM) and by an immunological enzyme luminescence me hod (Ikawa e al., 2010). The AFM analysis e ealed ha TMV g adually embeds in o he azo- polyme as a g oo e benea h he i us inc eases du ing i adia ion, i.e., as he azopolyme su ace de o ms complemen a y o he shape o TMV. Also, he luminescence assay e ealed ha he immobiliza ion e iciency inc eased p opo ionally o he pho oi adia ion ime. Thus, he pho o- physical induced change in he su ace shape and he isome iza ion o he azo-dyes enables o imp in bo h he opog aphical ea u e and he su ace cha ac e is ics o i us like TMV (Ikawa e al., 2010). 4.2. Tobacco nec osis i us Tobacco nec osis i us (TNV) is a 26 nm diame e nec o i us, which is no longe associa ed wi h diseases o obacco, bu wi h bean s ipple s eak and ulip nec osis diseases. This wo ldwide sp ead i us is ansmi ed by he aqua ic ungus Olpidium b assicae and o en occu s in i iga ed soils and g eenhouses (Palukai is, 2017; Tolin, 2008). Wanka e al. (2016) o med molecula imp in s o he TNV wi hin poly hiophene nano ilms o app oxima e 200 nm hickness, which ha e been elec ochemically deposi ed on o conduc ing gold su aces. Upon ebinding, he TNV poly hiophene complex changes he luo escence in ensi y o he nano ilm p opo ionally o he concen a ion o TNV. I was shown ha he nano ilm esponds o TNV wi hin 2 min in he 0.1–10 ng L −1 ange and wi h a limi o de ec ion (LOD) o 2.29 ng L −1 . Mo eo e , he selec i i y was es ed using TMV, which is od-shaped and bigge han TNV, and he senso esponse showed o be selec i e o TNV. This wo k has demons a ed he po en ial o luo escence o speci ic, M.S. Amo im e al. Biosenso s and Bioelec onics: X 10 (2022) 100131 5 label- ee and apid de ec ion o TNV in wa e esou ces using nano ilm senso s (Wanka e al., 2016). 4.3. Adeno i us Adeno i us (AdV) i ion has a unique icosahed al shape wi h abou 90 nm in diame e . AdVs cause espi a o y, ocula , u ina y ac and gas oin es inal, ansmi able, and some imes highly con agious, in- ec ions. These in ec ions a e gene ally sel -limi ing, bu o unknown easons, hey can lead o local epidemics. Howe e , he e a e cu en ly no a ailable he apies p o ed e ec i e an i-AdV. Fo his eason, he e is an u gency o ha e apid de ec ion and ea ly diagnosis o his i us (G ebe and Fla , 2019). Al in as e al. (2015) epo ed a no el MIP echnology o speci ic and sensi i e ecogni ion o AdVs based on MIP nanopa icles coupled o su ace plasmon esonance de ec ion. In his wo k, MIP nanopa icles we e p oduced by a solid-phase syn hesis me hod whe e glass beads we e used as solid suppo o he immobiliza ion o he a ge AdVs, while a mix u e o monome s, namely N-isop opylac ylamide, ac ylic acid, N,N′-me hylenebisac ylamide, N- e -bu ylac ylamide, and N-(3-aminop opyl) me hac ylamide hyd ochlo ide, was used o poly- me iza ion. The ecogni ion o AdVs was s udied in a concen a ion ange o 0.01–20 pmol L −1 , and a LOD o 0.02 pmol L −1 was ob ained (Al in as e al., 2015). A di e en syn he ic s a egy o AdVs cap u e was p oposed by using su ace-imp in ed co e-shell pa icles. The ma- e ial was ob ained by immobilizing he i uses on he su ace o mic ome e silica pa icles, ollowing by co-polyme iza ion o selec ed o ganosilanes and emo al o he empla e i uses (Gas e al., 2018) (Fig. 3). To p e en unspeci ic binding, a p o ein, bo ine se um albumin, was used as blocking agen . This sol-gel imp in ing me hod yielded excellen binding a ini y, selec i i y, and egene a ion abili y (Gas e al., 2018). Mo eo e , he amoun o bound i us was de e mined by quan i a i e PCR, bo h du ing i us imp in ing and ebinding expe i- men s, e ealing i s alue conside ing he absence o any p io DNA isola ion s eps (Gas e al., 2018). A la e expansion o his MIP me h- odology was p esen ed by Gas e al. (2020) by combining i wi h luo escence labeling. In his wo k, i was possible o isualize indi idual i uses a ached o he de eloped imp in ed pa icles by supe - esolu ion mic oscopies (Gas e al., 2020). 4.4. Japanese encephali is i us Japanese encephali is i us (JEV) is a posi i e sense single-s and RNA mosqui o-bo ne la i i us co e ed wi h a i al capsid. This i us causes Japanese encephali is, a i al encephali is ha a ec s housands o people e e y yea , mainly in he Asia Paci ic egion. Thus, he e is a g ea need o quick and low-cos de ec ion me hods o his i us (Ganeshpu ka e al., 2018; S ikas e al., 2018). In he wo k by Feng e al. (2018), luo escence de ec ion o JEV was demons a ed by eso ing o su ace molecula imp in ing on silica mic osphe es modi ied wi h a luo escen dye, dansyl chlo ide. The de eloped MIPs, p epa ed wi h (3-aminop opyl) ie hoxysilane (APTES) and e ae hyl o hosilica e (TEOS), showed o selec i ely ecognize JEV, by luo escence quenching, in he p esence o hepa i is A i us (HAV), simian i us 40 and abies i us. Mo eo e , he me hod p o ed o be sensi i e, gi ing a esponse wi hin 55 min, and wi h a LOD Fig. 3. Schema ic illus a ion o su ace-imp in ing co e-shell pa icles o AdV ecogni ion (A), and images o scanning elec on mic oscopy o ba e silica pa icles (a), imp in ed pa icles ob ained by he co-polyme iza ion o o ganosilanes (b) and a e lysis (c), non-imp in ed pa icles (d), and pa icles a e i us ebound (e), wi h schema ic inse s o AdV (e, ) (B). Copy igh 2018, Ame ican Chemical Socie y, Rep oduced wi h pe mission (Gas e al., 2018). M.S. Amo im e al. Biosenso s and Bioelec onics: X 10 (2022) 100131 6 in he picomola ange (Feng e al., 2018). Simila ly, Liang e al. (2016) de eloped a luo escen senso based on a MIP laye ancho ed on he su ace o luo escen silica mic osphe es (Liang e al., 2016). In his s udy, JEV was de ec ed based on luo escence esonance ene gy ans e be ween he i us as ene gy dono and he luo escen dye (py ene-1-ca boxaldehyde) as ene gy accep o . Thus, an enhancemen o luo escence in ensi y occu ed p opo ionally o he concen a ion o he i us in he ange o 24–960 pmol L −1 . The LOD was de e mined o be 9.6 pmol L −1 , and he selec i i y was demons a ed when es ing o he i uses, namely HAV, lep osy i us and abies i us (Liang e al., 2016). Taking ad an age o silica mic opa icles wi h a magne ic co e, Luo e al. (2019a) de eloped a magne ic su ace molecula ly imp in ed- esonance ligh sca e ing (RLS) senso o apid and highly sensi i e de ec ion o JEV (Luo e al., 2019a). The cap u e o JEV by he imp in ed Fe 3 O 4 @SiO 2 mic osphe es esul ed in an inc ease o he RLS in ensi y, wi h a esponse ime wi hin 20 min, and LOD o 1.3 pmol L −1 , allowing apid and sensi i e de ec ion o JEV in p ac ical applica ions. Rega ding he selec i i y, he senso demons a ed a selec i e esponse o JEV when o he i uses we e e alua ed (HAV, dimensionally di e en abies i us, simian acuola ing i us 40) (Luo e al., 2019a). A di e en luo escen senso based on a me al-o ganic amewo k (MOF) has also been p oposed (Yang e al., 2020). The MOF ma e ial (MIL-101) was coa ed wi h silica and u he inyl- unc ionalized o enable he imp in ing o JEV using zinc ac yla e as unc ional monome and EGDMA as c osslinke (Fig. 4). Mo eo e , polye hylene glycol (PEG) was used as blocking agen . In he p esence o JEV he in ensi y o he luo escence signal inc eased linea ly in a wide ange o concen a ions (50 pmol L −1 o 1400 pmol L −1 ) wi hin 20 min, also p esen ing a good selec i i y and a low LOD o 13 pmol L −1 . In addi ion, he MIP pa icles we e selec i e o JEV when HAV, abies, and lep osy i uses we e es ed (Yang e al., 2020). 4.5. In luenza i us In luenza i us belongs o he O homyxo i idae amily and can be di ided in h ee sub ypes A, B and C, which ha e simila s uc u e bu di e en an igenic p ope ies. In luenza i uses ha e oughly a sphe ical shape wi h a size o abou 80–120 nm and con ain a single-s anded nega i e-sense segmen ed RNA genome. The in ec ion by in luenza A i us (IAV), which is gene ally ound in humans, is mos common and se e e. This is a highly con agious ai bo ne disease, and he symp oms ange om mild a igue o espi a o y ailu e and dea h. This disease sp eads apidly and g ea ly a ec s he human popula ion globally wi hin a sho pe iod o ime (Dangi and Jain, 2012). In he wo k by Rand ian sile isoa e al. (2020), he op ical p ope ies o gold nanopa icles and he high swelling capaci y o polyol-based hyd ogels we e used o o m a nanocomposi e o bo h ha changes i s colou and sh inkage in he p esence o IAV (Rand ian sile isoa e al., 2020). The hyd ogel was o med by click chemis y using unc ional dend i ic polyglyce ol cyclooc yne and polye hylene glycol diazide while sialic acids p o ided he speci ic and high binding a ini y o he hemagglu inin on IAV. Thus, he empla e IAV (s ain H3N2) mixed wi h gold nanopa icles unc ionalized wi h sialic acids we e added o he hyd ogel p ecu so mix u e. The esponsi e imp in ed hyd ogel p o- duced an op ical and mechanical esponse upon emo al and ebound o he IAV (Rand ian sile isoa e al., 2020). Di e en MIPs, based on Fig. 4. Scheme o JEV imp in ing on he su ace o a MOF ma e ial, using zinc ac yla e as unc ional monome and PEG as passi a ing agen , and he de ec ion p inciple. Copy igh 2020, Else ie , Rep oduced wi h pe mission (Yang e al., 2020). M.S. Amo im e al. Biosenso s and Bioelec onics: X 10 (2022) 100131 7 ac ylamide, me hyl me hac yla e, me hac ylic acid and N- inyl- py olidone, de eloped o he pa hogenic s ain H5N1 ha e been s udied and op imized bo h by bulk imp in ing suspension copolyme - iza ion o o m polyme beads and by su ace imp in ing using a i us s amping and o ming a hin- ilm. These MIPs ecognize IAV, being, in his way, a iable me hod o he de ec ion o he i us (Sangma e al., 2017). Ano he in e es ing wo k was de eloped by Wangcha eansak e al. (2013), which applied a molecula imp in ing s a egy as a sc eening p o ocol o di e en in luenza A sub ypes (H5N1, H5N3, H1N1, H1N3 and H6N1), c ea ing MIPs o each sub ype and e alua ing senso cha ac e is ics on a QCM (Wangcha eansak e al., 2013). The senso s we e p epa ed on gold elec odes o a dual-elec ode QCM by spin-coa ing he p e-polyme , consis ing o ac ylamide, me hac ylic acid, me hyl me hac yla e and N- inylpy olidone, and polyme izing he mix u e in he p esence o a s amp coa ed wi h he empla e i us. The senso showed o be sensi i e, leading o LODs as low as 10 5 pa - icles mL −1 , and selec i e, allowing o i us sub ype cha ac e iza ion and apid sc eening (Wangcha eansak e al., 2013). This imp in ing me hodology was la e used o sc een molecula p obes, o di e en size, shape and binding a ini ies, which could bind o he i us (H5N1) and induce a con o ma ional change (Wangcha eansak e al., 2014). The me hod was success ul in di e en ia ing be ween induced con o ma- ional e ec s a ising om high and low a ini y ligands because he MIP binding was p opo ionally a ec ed in compa ison o he ecogni ion o unmodi ied i us. These esul s sugges a e y in e es ing applica ion o MIPs o s udy no el inhibi o s and hei mode o ac ion (Wangcha - eansak e al., 2014). Despi e su ace imp in ing by s amping coupled o QCM has been highly explo ed o a ious IAV sub ypes (Liebe zei e al., 2011; Wangcha eansak e al., 2013), ano he s a egy has been also ad anced h ough he syn hesis o g anula MIPs by p ecipi a ion polyme iza ion (Sukjee e al., 2017). Fou monome s, namely ac yl- amide, me hac ylic acid, me hyl me hac yla e and N- inylpy olidone, we e used o p epa e he MIP. The me hod was conside ed low-cos and easy as he MIPs can be p oduced in la ge quan i ies, while he ecog- ni ion abili y o he MIP was es ima ed based on indi ec agglu ina ion es and also on QCM, he la es demons a ing a be e analy ical pe - o mance (Sukjee e al., 2017). 4.6. Hepa i is i us HAV is a non-en eloped single-s anded posi i e-sense RNA i us, wi h a size o 7.5 kb and a diame e o 27 nm, a membe o he Pico - na i idae amily ha is sp ead by he aecal-o al ou e, bu he si e o i us eplica ion is he li e . HAV causes he hepa i is A disease, which is an acu e in lamma o y condi ion and is cha ac e ized by se e al symp oms, including ano exia, a igue, weigh loss and jaundice. Fig. 5. Schema ic illus a ion o MIPs luo escence senso (A), he me al chela ion and six-membe ed ing o med be ween he empla e and zinc ac yla e (B), e ec o indica ed concen a ions o HAV and HBV on luo escence in ensi y o MIPs (a) wi h an inse o luo escence images o hyb id MIPs solu ions unde a 365 nm UV lamp, and he espec i e e ec on he luo escence in ensi y o NIPs (b) (C). Copy igh 2019, Ame ican Chemical Socie y, Rep oduced wi h pe mission (Luo e al., 2019b). M.S. Amo im e al. Biosenso s and Bioelec onics: X 10 (2022) 100131 8 Howe e , he symp oms o he disease a e he e ogeneous depending on he age o in ec ion, anging om silen in lec ions mainly in young child en o classical hepa i is in olde age g oups, and a al cou ses o he disease also occu (A e ho e al., 2015; Do zaue , 2008; Gup a, 2018). The MIP echnology has also been p o i ing om he use o s imuli- esponsi e polyme s. In a wo k by Liu e al. (2017), he use o a he - mosensi i e polyme made o N-isop opylac ylamide enabled he de elopmen o an imp in ed polyme on he su ace o silica pa icles as suppo ma e ial o ecogni ion o HAV (Liu e al., 2017). The speci ic cap u e o he i us occu ed a 40 ◦C and he elease a 20 ◦C, i.e., a he lowe empe a u e he polyme swelled and a he highe one he polyme sh inked. The senso pe o mance was ollowed by RLS in- ensi y, which inc eased upon HAV de ec ion. The senso showed o be selec i e when es ed in he p esence o in e e ing i uses, namely hepa i is B i us (HBV), abies i us and JEV, and demons a ed a e y good LOD o 1.1 pmol L −1 (Liu e al., 2017). Likewise, Luo e al. (2020) applied MIP nanop obes o he selec i e de e mina ion o HAV h ough RLS echnique, ob aining a lowe LOD o 0.1 pmol L −1 and a linea concen a ion ange o 0.02–2.0 nmol L −1 (Luo e al., 2020). In his wo k, he pH-sensi i e imp in ed polyme dime hylaminoe hyl me h- ac yla e was p epa ed (swelling wi h pH dec ease) on he su ace o a MOF suppo . Mo eo e , he pH- esponsi e MOF nanocomposi e p e- sen ed a selec i e esponse, which indica ed i s po en ial abili y o de e mine HAV in eal applica ions (Luo e al., 2020). An enhancemen o RLS in ensi y has been also employed in o he wo ks whe e MIPs we e p oduced by su ace imp in ing o silica o magne ic pa icles (Yang e al., 2017; Zhang e al., 2018). In bo h hese wo ks, he sel -polyme iza ion abili y o dopamine, c ea ing a polydopamine-based MIP, was s udied as a biomime ic mussel-inspi ed app oach, esul ing in selec i e and sensi i e senso s wi h LODs in he picomola ange (Yang e al., 2017; Zhang e al., 2018). In a di e en ype o s a egy, Luo e al. (2018) c ea ed a luo escence MIP made om CdTe/CdS quan um do (QD)-based silica nanopa icles using a sol-gel p ocess. The HAV was selec i ely cap u ed by he imp in ed polyme laye , and he luo escen quenching o he QDs was analysed wi hin 20 min. Mo eo e , a linea ange be ween 0.2 and 1.4 nmol L −1 and a LOD o 88 pmol L −1 we e ob ained (Luo e al., 2018). Rega ding he HBV, i s genome is a pa ially double-s anded ci - cula DNA o abou 3.2 kb pai s ha belong o he Hepadna i idae amily (A e ho e al., 2015; Do zaue , 2008; Gup a, 2018). HBV is esponsible o he po en ially li e- h ea ening li e in ec ion: hepa i is B. Hepa i is B is a majo global heal h p oblem ha leads o a wide spec um o li e diseases, anging om acu e o ch onic hepa i is, ci hosis, and hepa- ocellula ca cinoma (li e cance ) (Liang, 2009). Some s udies combine he use o MIPs wi h o he ecogni ion p obes. An app oach de eloped o de ec HBV employed a dual- ecogni ion me hod based on MIPs and ap ame s in a sandwich RLS senso (Chen e al., 2021). The MIP a ge ing HBV was achie ed by su ace imp in ing made o TEOS on ca bon sphe es as ca ie s, while he o he p obe was ob ained by modi ica ion o silicon sphe es wi h ap ame s. The use o a second p obe was mean o imp o e he speci ic ecogni ion o HBV and o p o ide a second enhancemen o he RLS in ensi y. Wi h his MIP-HBV-ap ame sandwich, he senso esponse demons a ed high sensi i i y and good selec i i y, wi h a LOD o 0.011 nmol L −1 (Chen e al., 2021). The e a e also a emp s o pu sue he simul aneous de ec ion o mul iple i uses. In he wo k o Luo e al. (2019) he use o g een and ed colou ed QDs enabled such mul iplex analysis o de ec bo h HAV and HBV (Luo e al., 2019b). The MIPs we e syn hesized using zinc ac yla e and N-isop opylac ylamide as monome s on he su ace o g een and ed emi ing QDs coa ed wi h shells o silica (Fig. 5). The luo escence senso enabled simul aneous de ec ion o HAV (LOD o 3.4 pmol L −1 ) and HBV (LOD o 5.3 pmol L −1 ) by a dec ease in bo h emission peaks (Luo e al., 2019b). 4.7. Zika i us Zika i us (ZIKV) is a posi i e sense, single-s and RNA i us wi h a genome size o app oxima ely 11 kb. ZIKV is an a h opod-bo n i us (a bo i us) belonging o he Fla i i idae amily. The ansmission o ZIKV ypically occu s h ough he bi e o an in ec ed emale mosqui o du ing i s blood eeding, leading o he appea ance o he ZIKV disease. I is es ima ed ha mos cases o his disease a e asymp oma ic. How- e e , i has ecen ly caused ou b eaks and epidemics, being associa ed Fig. 6. Schema ic ep esen a ion o he MIP p epa ed o CSFV, using se e al monome s (ac ylamide – AAM; me hac ylic acid – MAA; me hyl me hac yla e – MMA; N- inylpy olidone – VP), he c osslinke (dihyd oxye hylene-bisac ylamide – DHEBA) and he ini ia o o he polyme iza ion (2,2 ′-azobis(iso- bu y oni ile) – AIBN). The su ace-imp in ed poly- me enabled o de elop a QCM-based senso . Copy igh 2020, Rep oduced unde he e ms and condi ions o he C ea i e Commons A ibu ion BY- NC-ND 4.0 License (Klangp apan e al., 2020). M.S. Amo im e al. Biosenso s and Bioelec onics: X 10 (2022) 100131 9 wi h se e e clinical mani es a ions and congeni al mal o ma ions (Zanluca and dos San os, 2016). Rico a e al. (2019) de eloped a po en ial poin -o -ca e diagnos ic sys em using a chip-based po en iome ic senso inco po a ing he mo- lecula imp in ing echnology (Rico a e al., 2019). The imp in ing p ocess was designed by he co-adso p ion o he ZIKV and a sel -assembled monolaye (SAM) o hyd oxyl- e mina ed alkane hiols on a gold-coa ed chip. This sys em was able o de ec 10 −1 PFU mL −1 ZIKV in a bu e ed solu ion, and 10 PFU mL −1 ZIKV in samples o human sali a con aining clinical i al loads, hus wi h g ea p ospec s o apid and accu a e sc eening o ZIKV (Rico a e al., 2019). 4.8. Polio i us Polio i us is a non-en eloped, posi i e-sense, single-s anded RNA i us, membe o he amily Pico na i idae, which causes poliomyeli is. Polio i us is mainly ansmi ed by he aecal-o al ou e and eplica es in he pha ynx and lowe in es inal ac . Polio i us is en i ely asymp- oma ic in 90% o indi iduals, howe e , in ewe han 1% o cases he i us en e s he cen al ne ous sys em, in ec ing and des oying mo o neu ons, leading o muscle weakness and acu e laccid pa alysis (Cla - wo hy, 2014; Ga g and Ka s , 2016; T oy and Maldonado, 2012). Wang e al. (2010) applied su ace molecula imp in ing using SAMs on a gold-coa ed silicon chip (Wang e al., 2010). The design consis ed in co-adso bing he empla e wi h hyd oxyl- e mina ed alkane hiol mole- cules on he me al su ace allowing hem o o m he SAM. A e em- pla e emo al, he imp in ed ca i ies a e le behind on he senso su ace. As demons a ed in a simila app oach o ZIKV (Rico a e al., 2019), his s a egy was success ully applied in he po en iome ic de ec ion o polio i us, wi h no c oss- eac i i y o AdV (Wang e al., 2010). 4.9. Classical swine e e i us Classical swine e e i us (CSFV) o 40-60 nm in diame e , a e en eloped i us o icosahed al symme y o he amily Fla i i idae, and he i al genome is a single-s anded posi i e-sense RNA o app oxi- ma ely 12.3 kb. CSFV in ec ion leads o a b eakdown o he immune sys em accompanied by a p o-in lamma o y esponse. This disease is associa ed wi h many symp oms, including se e e lymphopenia and lymphocy e apop osis, h ombocy openia, pla ele agg ega ion, bone ma ow deple ion, hymus a ophy, and hymocy e apop osis. Since classical swine e e is conside ed one o he mos ele an e-eme gen a al i al diseases in swine, he e is an economic necessi y ha u ges apid ea ly de ec ion o his i us (Ganges e al., 2020). A MIP ecog- ni ion elemen has been de eloped o de ec his i us, elying on CSFV s amping ha was p essed on a p e-polyme o ac ylamide, me hac ylic acid, me hyl me hac yla e and N- inylpy olidone, spin-coa ed on QCM gold elec odes (Fig. 6). This senso selec i ely binds CSFV, wi h a LOD o 1.7 μ g mL −1 (Klangp apan e al., 2020). 4.10. Foo and mou h disease i us Foo and mou h disease i us (FMDV) is a small, icosahed al, non- en eloped, single-s anded, posi i e-sense RNA i us o app oxima ely 8.3 kb, ha belongs o he amily Pico na i idae. This highly in ec ious pa hogen causes se ious debili a ing disease, he oo and mou h disease, in ca le and o he li es ock and wildli e, and is hus conside ed a ele an e e ina y pa hogen (Malik e al., 2017; Yan e al., 2017). An elec ochemical polyme iza ion o he oxidized o-aminophenol ilm wi h FMDV se o ype O on a gold sc een-p in ed elec ode deployed a new ecogni ion sys em o his i us (Hussein e al., 2019). The biosenso showed a high selec i i y o FMDV se o ype O in compa ison o se o ype A, SAT-2, inac i a ed se o ype O, and lumpy skin disease i us, and a LOD o a ound 2 ng mL −1 . Besides, he as esponse (5 min) and he eusabili y o he biosenso , p esen s a p omising, a o dable, and po able ool ha could be used in he ield (Hussein e al., 2019). 4.11. O he i uses Cumbo e al. (2013) desc ibed a syn he ic s a egy o p oduce o ganic/ino ganic nanopa icula e hyb ids con aining i us imp in s on he su ace. Fo ha , i us-imp in ed pa icles we e p oduced o plan i uses as models, namely oma o bushy s un i us (TBSV) and u nip yellow mosaic i us (TYMV) (Cumbo e al., 2013). The i uses we e i s bound on he su ace o silica nanopa icles, ollowed by incuba ion wi h a mix u e o o ganosilanes and subsequen polycondensa ion o g ow an o ganosilica (silsesquioxane) ecogni ion laye , which a e i us emo al display he ee imp in s. The TBSV and TYMV imp in ed silica nanopa icles displayed a ema kable selec i i y and a ini y o bo h i uses, ecognizing hem in wa e a concen a ions down o he pico- mola ange (Cumbo e al., 2013). A simila app oach was pu sued bu using i us-like pa icles as a sa e subs i u e o he imp in ing o human pa hogenic No o i uses, and he MIP showed also an excellen a ini y in he picomola ange (Syko a e al., 2015). A no el double imp in ing me hod has been p oposed o he apple s em pi ing i us (ASPV) (Bai and Spi ak, 2014). The Fig. 7. Scheme o he bioimp in ing p ocess o ob ain i us esponsi e supe - ap ame hyd ogels, using polyme izable speci ic ap ame s copolyme ized wi h N-isop opylac ylamide – NIPAM and ac ylamide – AM as monome s, N,N ′- me hylenebisac ylamide – MBAA as c osslinke , and ammonium pe sul a e – APS and N,N,N′,N′- e ame hyle hylenediamine (TEMED) o ini ia ion o he polyme iza ion in phospha e-bu e ed saline – PBS (A); op ical mic oscopy images o he esponsi e MIP o ASPV and he co esponding lase di ac ion pa e ns wi hou i us (a, b) and in he p esence o ASPV (c, d) (B). Copy igh 2014, Wiley-VCH, Rep oduced wi h pe mission (Bai and Spi ak 2014). M.S. Amo im e al.