A nanotube/polymer composite biosensing thin-film transistor platform for C-reactive protein detection

In the present study, a back-gate thin-film transistor (TFT) based on a single-walled carbon nanotubes (SWCNTs)/poly(9,9-dioctylfluorene-co-bithiophene) (F8T2) composite semiconductor is proposed as electronic label-free immunosensor for the detection of the C-reactive protein (CRP). The nano-composite semiconducting ultra-thin film is deposited on the channel area of the TFT and is functionalized with a monoclonal anti-CRP antibody coating acting as biorecognition layer. The immunesensor was then used for the selective detection of the CRP both in phosphate buffered saline (PBS) solution and in human serum samples. The proposed immunosensor exhibits high current (10 - 20 μA) and good field-effect carriers mobility. Furthermore, the CRP could be revealed at a detection limit as low as 1 mg/L and in a wide dynamic range (from 0.4 nM to 2.2 μM).