Research Article
Nanoelectrochemical Immunosensors for Protein Detection
@INPROCEEDINGS{10.1007/978-3-642-04850-0_25, author={Alessandro Carpentiero and Manuela Leo and Ivan Garcia Romero and Stefano Pozzi Mucelli and Freimut Reuther and Giorgio Stanta and Massimo Tormen and Paolo Ugo and Martina Zamuner}, title={Nanoelectrochemical Immunosensors for Protein Detection}, proceedings={4th International ICST Workshop on Nano-bio-sensing}, proceedings_a={NANO-BIO-SENSING}, year={2012}, month={5}, keywords={Nanoelectrode electrochemical immunosensor proteomics trastuzumab voltammetry electron beam lithography}, doi={10.1007/978-3-642-04850-0_25} }- Alessandro Carpentiero
Manuela Leo
Ivan Garcia Romero
Stefano Pozzi Mucelli
Freimut Reuther
Giorgio Stanta
Massimo Tormen
Paolo Ugo
Martina Zamuner
Year: 2012
Nanoelectrochemical Immunosensors for Protein Detection
NANO-BIO-SENSING
Springer
DOI: 10.1007/978-3-642-04850-0_25
Abstract
Nanoelectrochemical immunosensors fabricated by templated electrodeposition of gold nanoelectrodes inside the pores of polycarbonate (PC) track-etched membranes, followed by the immobilization of the biorecognition elements on the surrounding PC, have proven high sensitivity and specificity for protein detection. The signal transduction scheme involves a suitable redox mediator added to the sample solution to shuttle electrons from the gold nanoelectrodes to the biorecognition layer, both elements being in strict spatial proximity. Highly improved signal-to-background current ratio, which are peculiar of NEEs with respect to other electrochemical transducers, can be exploited in this way. Two detection schemes were tested: one based on the direct immobilization of the target protein on the PC of the NEE (approach A) and the other based on the immobilisation on PC of an antibody to capture the target protein (approach B). The biorecognition process was completed by adding a primary antibody and a secondary antibody with horse radish peroxidase (HRP) as enzyme label; methylene blue was the redox mediator added to the electrolyte solution. Typical target analytes were single chain fragment variable proteins, for approach A, and trastuzumab (also known as Herceptin®), for approach B. NEE-based capture sensors were tested successfully to detect small amounts of the receptor protein HER2 in biological samples. Finally, motivated by the target of a better control of the geometrical characteristics of ensembles of nanoelectrodes (size, density, geometrical arrangement, and degree of recession), and by the positive results obtained with track-etch membranes of PC from the standpoint of protein immobilization, we demonstrated the fabrication of nanobiosensors by patterning ordered arrays of nanoelectrodes (NEAs) by electron beam lithography (EBL) on polycarbonate. EBL results perfectly suitable for the top-down fabrication of arrays of nanobiosensors on thin PC films deposited on gold coated silicon.
