A Functional Bio-Interlayer Organic Field-Effect Transistor (FBI-OFET) sensor, embedding a streptavidin protein capturing layer, capable to perform label-free specific electronic detection of biotin at 3 part-per-trillion (mass fraction) or 15 pM, is here proposed. The response shows a logarithmic dependence on the analyte concentration along with a dynamic range spanning over five orders of magnitude. The optimization of the FBI analytical performances is achieved by depositing the capturing layer through a controllable Layer-by-Layer (LbL) assembly, while an easy processable spin-coating deposition is proposed for potential low-cost production of equally highly performing sensors. A Langmuirian adsorption based model allows to rationalize the analyte binding to the capturing layer whose analytical performances are discussed accordingly. The FBI-OFET device is shown to operate also with an antibody interlayer as well as with an ad hoc designed micro-fluidic system. These occurrences, along with the proven extremely high sensitivity and selectivity, open to FBI-OFETs appraisal as a suitable platform for disposable electronic strip-tests for assays in biological fluids requiring very low detection limits.
Part-per-trillion label-free electronic bio-analytical detection
MAGLIULO, MARIA;SABBATINI, Luigia;CIOFFI, NICOLA;PALAZZO, Gerardo;TORSI, Luisa
2013-01-01
Abstract
A Functional Bio-Interlayer Organic Field-Effect Transistor (FBI-OFET) sensor, embedding a streptavidin protein capturing layer, capable to perform label-free specific electronic detection of biotin at 3 part-per-trillion (mass fraction) or 15 pM, is here proposed. The response shows a logarithmic dependence on the analyte concentration along with a dynamic range spanning over five orders of magnitude. The optimization of the FBI analytical performances is achieved by depositing the capturing layer through a controllable Layer-by-Layer (LbL) assembly, while an easy processable spin-coating deposition is proposed for potential low-cost production of equally highly performing sensors. A Langmuirian adsorption based model allows to rationalize the analyte binding to the capturing layer whose analytical performances are discussed accordingly. The FBI-OFET device is shown to operate also with an antibody interlayer as well as with an ad hoc designed micro-fluidic system. These occurrences, along with the proven extremely high sensitivity and selectivity, open to FBI-OFETs appraisal as a suitable platform for disposable electronic strip-tests for assays in biological fluids requiring very low detection limits.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
