Reconfigurable sensor for the optical detection of biomolecular targets by metal-ion mediated interactions

Reconfigurable sensor for the optical detection of biomolecular targets by metal-ion mediated interactions 0.0 0.5 1.0 1.5 2.0 0 20 40 60 80 100 EOT - EOT0 (nm) [ATP] (mM) 0 20 40 60 Sensitivity (nm/mM) Fe3+ 0.00 0.01 0.02 0.03 0.04 LoD (mM) Tiziano Di Giulio1, Francesco Gagliani1, Cosimino Malitesta1, Martina Corsi2, Giuseppe Barillaro2, Elisabetta Mazzotta1 1Dipartimento di Scienze e Tecnologie Biologiche e Ambientali (Di.S.Te.B.A.), Università del Salento, via Monteroni 73100 Lecce –Italy. 2Dipartimento di Ingegneria dell’Informazione, Università di Pisa via G. Caruso 16, 56126 Pisa – Italy. Abstract Methods Results a) Carnosine detection Sensor reconfiguration was achieved by switching on the PSiO2 surface from Cu2+ to Zn2+, therefore assessing the sensing capabilities of Cu2+-functionalized and Zn2+ reconfigured devices for the detection of carnosine, and then by reconfiguring the sensor for a distinct target analyte, adenosine triphosphate (ATP), by substituting Cu2+ with Fe3+ ions. Both Cu2+-functionalized and Zn2+ reconfigured sensors exhibit impressive sensing performance in CAR detection, while the Fe3+-reconfigured sensor demonstrates effective sensing of ATP. These results underscore the successful reconfiguration of the sensor through the proposed surface chemistry, offering a promising avenue for adaptive and versatile sensor applications. Conclusions presenting author: [email protected];corresponding author: [email protected]. XXII Conferenza Nazionale Sensori e Microsistemi (AISEM 2024) The reconfiguration of chemical sensors, defined as the ability to adapt the sensor to new operational scenarios such as emerging target analytes, holds significant potential for rapid and cost-effective responses to dynamic changes at PSIO2SCAFFOLDS FUNCTIONALIZATION TOWARDS SENSOR DEVELOPMENT SENSOR RECONFIGURATION b) ATP detection PSiO2scaffold (a silane with -COOH moieties) GLYMO-IDA bare PSiO2 Silanization with GLYMO-IDA grafting metal-ion chelation target binding GLYMO-IDA Cu2+ Zn2+ Fe3+ Ni2+ 0 50 100 150 200 250 300 350 EOT - EOT PSiO2(nm) 920930940950 3000 4000 5000 6000 7000 CPS Binding energy (eV) GLYMO-IDA Cu2+ 705715725735 2500 5000 7500 10000 12500 15000 CPS Binding energy (eV) GLYMO-IDA Fe3+ MONITORING OF PSIO2SCAFFOLDS FUNCTIONALIZATION AND TARGET DETECTION BY UV-VIS SPECTROSCOPY AND XP SPECTROSCOPY (XPS) 1400 1200 1000 800 600 400 200 0 EDTA treatment Zn2+/GLYMO-IDA GLYMO-IDA Cu2+/GLYMO-IDA carnosine removal Intensity (a.u.) Binding energy (eV) Zn 2p Cu 2p O 1s N 1s C 1s Si 2p 0.1 0.5 1 0 10 20 30 40 50 EOT-EOT0 (nm) Concentration (mM) carnosine anserine l-histidine glycil-l-proline b-alanine 1 5 15 30 0 5 10 15 20 25 30 35 40 45 EOT - EOT0 (nm) Time (days) Sensor reconfiguration was achieved by switching on the PSiO2 surface different metal ions. Carnosine detection tests using GLYMOIDA@Cu2+/Zn2+ receptors demonstrated their capabilities to recognize and bind the target by the interaction with its histidine moiety. Moreover, ACKNOWLEDGMENT: This work was partially funded by the European Union Horizon Europe programme under grant agreement No 101046946 (RESORB). (by a washing with HCl) (by the exposure of the sensor with target solutions) PSiO2exposure to metal-ion solutions 0.1 0.25 0.5 1 0 10 20 30 40 50 EOT-EOT0 (nm) [Carnosine] (mM) Cu2+ Zn2+ PSiO2functionalization Carnosine detection by GLYMO-IDA@Cu2+/Zn2+ receptor PSiO2scaffolds were successfully functionalized with GLYMO-IDA and different metal ions (Cu2+ , Zn2+ , Ni2+ and Fe3+ ) were anchored on the transducer surface, as demostrated by the change in EOT signal and high-resolution XPS signals. 800700600500400 0 10 20 30 40 50 GLYMO-IDA Cu2+ Fe3+ Ni2+ Zn2+ Reflectance (%) Wavelength (nm) ATP detection by GLYMO-IDA@Fe3+ receptor From reflectance spectra to EFFECTIVE OPTICAL THICKNESS (EOT) signal Fabry-Perot fringes are described by the realationship: m λ = 2nL EOT=2nL “n” effective refractive index; “L” thickness of the PSiO2 layer. different levels, although it is still a challenge. This study presents a reconfigurable label-free optical sensor that capitalizes on a versatile immobilization technique employing a metal ion chelating agent on a nanostructured porous silica (PSiO2) optical transducer for detecting various biomolecules, namely carnosine dipeptide and adenosintriphosphate (ATP). Fe3+ ATP Target removal ATP 0 50 100 150 200 250 300 EOT - EOTPSIO2 (nm) Cu2+ can be easily switched with Zn2+ by a preliminary washing with an EDTA solution. GLYMO-IDA@Cu2+ -/Zn2+ -PSiO2were both able to bind carnosine. switching Cu2+ with Fe3+ ion on PSiO2 surface, a distinct target analyte, adenosine triphosphate (ATP) can be detected. Both Cu2+/Zn2+- and Fe3+ reconfigured sensors exhibit impressive sensing performance in CAR and ATP detection. These results underscore the successful reconfiguration of the sensor through the proposed surface chemistry, offering a promising avenue for adaptive and versatile sensor applications. Using the same sensor, Cu2+ ions on the surface of PSiO2 are removed by a washing with EDTA solution and replaced with Fe3+ ions; the reconfigured sensor is able to detect ATP in the analytical range 0.1 –2 mM, resulting in high sensitivity and low limit of detection Cu2+/Zn2+ chelation Carnosine binding EDTA regeneration Cu2+ removal ATP detection Fe3+ chelation Selectivity tests demonstrated the affinitity of the sensor for the histidine-containing molecules. The sensor response is stable for at least 30 days.