Needle-type organic electrochemical transistor for spatially resolved detection of dopamine
Federica Mariani, Thomas Quast, Corina Andronescu, Isacco Gualandi, Beatrice Fraboni, Domenica Tonelli, Erika Scavetta, Wolfgang Schuhmann
Abstract
Abstract In this work, the advantages of carbon nanoelectrodes (CNEs) and orgonic electrochemical transistors (OECTs) were merged to realise nanometre-sized, spearhead OECTs based on single- and double-barrel CNEs functionalised with a conducting polymer film. The needle-type OECT shows a high aspect ratio that allows its precise positioning by means of a macroscopic handle and its size is compatible with single-cell analysis. The device was characterised with respect to its electrolyte-gated behaviour and was employed as electrochemical sensor for the proof-of-concept detection of dopamine (DA) over a wide concentration range (10 −12 —10 −6 M). Upon application of fixed drain and gate voltages ( V d = − 0.3 V, V g = − 0.9 V, respectively), the nano-sized needle-type OECT sensor exhibited a linear response in the low pM range and from 0.002 to 7 μM DA, with a detection limit of 1 × 10 −12 M.