title: Optoelectrochemical biorecognition by optically transparent highly conductive graphene-modified fluorine-doped tin oxide substrates.
abstract: Both optical and electrochemical graphene-based sensors have gone through rapid development, reaching high sensitivity at low cost and with fast response time. However, the complex validating biochemical operations, needed for their consistent use, currently limits their effective application. We propose an integration strategy for optoelectrochemical detection that overcomes previous limitations of these sensors used separately. We develop an optoelectrochemical sensor for aptamer-mediated protein detection based on few-layer graphene immobilization on selectively modified fluorine-doped tin oxide (FTO) substrates. Our results show that the electrochemical properties of graphene-modified FTO samples are suitable for complex biological detection due to the stability and inertness of the engineered electrodic interface. In addition, few-layer immobilization of graphene sheets through electrostatic linkage with an electrochemically grafted FTO surface allows obtaining an optically accessible and highly conductive platform. As a proof of concept, we used insulin as the target molecule to reveal in solution. Because of its transparency and low sampling volume (a few microliters), our sensing unit can be easily integrated in lab-on-a-chip cell culture systems for effectively monitoring subnanomolar concentrations of proteins relevant for biomedical applications.
authors.affiliation: Department of Industrial Engineering, University of Padova , Via Marzolo 9, 35131 Padova, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Lamberti
authors.forename: L
authors.initials: L
authors.lastname: Brigo
authors.forename: M
authors.initials: M
authors.lastname: Favaro
authors.forename: C
authors.initials: C
authors.lastname: Luni
authors.forename: A
authors.initials: A
authors.lastname: Zoso
authors.forename: M
authors.initials: M
authors.lastname: Cattelan
authors.forename: S
authors.initials: S
authors.lastname: Agnoli
authors.forename: G
authors.initials: G
authors.lastname: Brusatin
authors.forename: G
authors.initials: G
authors.lastname: Granozzi
authors.forename: M
authors.initials: M
authors.lastname: Giomo
authors.forename: N
authors.initials: N
authors.lastname: Elvassore
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005461:Fluorine / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D007328:Insulin / Q000032:analysis*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D012031:Refractometry / Q000295:instrumentation*; D017971:Tin Compounds / Q000737:chemistry*
chemical_list: D052157:Aptamers, Nucleotide; D007328:Insulin; D017971:Tin Compounds; D005461:Fluorine; D006108:Graphite; C045358:stannic oxide
keywords: FRET; FTO; TCO; electrochemically reduced graphene oxide; insulin detection; optoelectrochemical analysis