Electric‐Field‐Assisted Growth of Functionalized Poly(3,4‐ethylenedioxythiophene) Nanowires for Label‐Free Protein Detection

Abstract

The construction of functionalized poly(3,4-ethylenedioxythiophene) (PEDOT) nanowire devices for label-free protein detection is reported. Direct growth/assembly of PEDOT nanowires with carboxylic acid side-chain functional groups (poly(EDOT-COOH)) across the electrode junction is achieved by using an electric-field-assisted method. These functionalized PEDOT nanowire devices show typical depletion-mode p-type field-effect transistor (FET) properties. Upon conjugation with a protein-binding aptamer, the PEDOT nanowire FET devices are used for label-free electronic detection of a target protein of interest. The binding of a positively charged protein causes a substantial decrease in current flow, attributed to the specific interaction between target protein molecules and aptamer-conjugated polymer chains.

The electrochemical growth of conducting polymer “nanowires”

“…The method also usually requires an alternating potential difference between the electrodes. Growth of isolated single dendrites with constant potential difference across the gap between parallel electrodes, has only been successful [13][14][15][16] in the absence of any electrolyte. The AC polarization is usually square wave and typically in the range of a few kHz to 1 MHz, with amplitude up to 20 V depending on the frequency.…”

Progression in sensing cardiac troponin biomarker charge transductions on semiconducting nanomaterials

“…In the study by Lee et al [21], respectively. The device also exhibited rapid detection and stabilization to detect IgE proteins, as fast as ~20 s. A demonstration of p-type PEDOT nanowire for protein detection was reported by Xie et al [50] and was electrochemically grown between two Au electrodes from a carboxylic acid-functionalized EDOT (EDOT-COOH) monomer solution by applying an electric field. …”

“…The device managed to detect thrombin proteins down to 1nM. Although the CP nanowires by Huang et al[49] and Xie et al[50] demonstrated the detection of IgE, MUC1 and thrombin, these studies verified the capability of using PPY and PEDOT nanowires for integration with FET-based biosensors' transducers for different protein detection; thus, these can be used for the detection of cTn biomarkers.…”

Large areain situfabrication of poly(pyrrole)-nanowires on flexible thermoplastic films using nanocontact printing

“…The first methods to synthesize PPy-NWs used electronic microscopy, photolithography, and electrochemical techniques, for e.g. (via dip-pen lithography and electrochemical polymerization) [22,23]. A common fabrication technique of PPy-NWs based devices was carried out by electrochemical polymerization in nanochannels between microfabricated gold electrodes [24] fashioned by e-beam lithography [25].…”