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Part per Trillion Label-Free Electronic Bioanalytical Detection
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posted on 2013-04-16, 00:00 authored by Maria Magliulo, Antonia Mallardi, Roberto Gristina, Francesca Ridi, Luigia Sabbatini, Nicola Cioffi, Gerardo Palazzo, Luisa TorsiA Functional Bio-Interlayer Organic Field-Effect Transistor
(FBI-OFET)
sensor, embedding a streptavidin protein capturing layer, capable
of performing label-free selective electronic detection of biotin
at 3 part per trillion (mass fraction) or 15 pM, is proposed here.
The response shows a logarithmic dependence spanning over 5 orders
of magnitude of analyte concentration. 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. Furthermore, a Langmuirian
adsorption based model allows rationalizing the analyte binding process
to the capturing layer. The FBI-OFET device is shown to operate also
with an antibody interlayer as well as with an ad hoc designed microfluidic system. These occurrences, along with the
proven extremely high sensitivity and selectivity, open to FBI-OFETs
consideration as disposable electronic strip-tests for assays in biological
fluids requiring very low detection limits.