Electrochemically Patterned Transducer with Anisotropic PEDOT through Liquid Crystalline Template Polymerization

We have demonstrated patterning of highly ordered nanostructured conducting PEDOT (poly­(3,4-ethylenedioxythiophene)) on glassy carbon electrode (GCE) through electrochemical polymerization of a biobased liquid crystalline template of EDOT-PDPPA (3-pentadecylphenyl phosphoric acid). Self-assembled “EDOT-PDPPA” in water exhibited lyotropic liquid crystalline (LC) phases of nematic gyroid, columnar, and lamellar phases. Studies revealed that, during electrochemical polymerization, PEDOT-PDPPA mimicked the anisotropic domains of its monomer LC template. Nyquist plot showed enhancement in conductivity with a positive change in the HOMO– LUMO gap. Further, the efficiency of the modified GCE was demonstrated as an electrochemical transducer for the detection of nicotine. It was observed that oxidation of nicotine occurs at lower potential (0.83 V) with higher current (54.63 μA) compared to bare GCE (1.1 V, 17.86 μA) with nanomolar detection. This simple strategy of electrochemical patterning of conductive polymer on a conventional electrode can be exploited for the high tech applications in miniaturized plastronic devices

Flexible Electrochemical Transducer Platform for Neurotransmitters

We have designed a flexible electrochemical transducer film based on PEDOT–titania–poly­(dimethylsiloxane) (PTS) for the simultaneous detection of neurotransmitters. PTS films were characterized using various techniques such as transmission electron microscopy, scanning electron microscopy, atomic force microscopy, four probe electrical conductivity, ac-impedance, and thermomechanical stability. The electrocatalytic behavior of the flexible PTS film toward the oxidation of neurotransmitters was investigated using cyclic voltammetry and differential pulse voltammetry. The fabricated transducer measured a limit of detection of 100 nm ± 5 with a response time of 15 s and a sensitivity of 63 μA mM^–1 cm^–2. The fabricated transducer film demonstrated for the simultaneous determination of epinephrine, dopamine, ascorbic acid, and uric acid with no interference between the analyte molecules. Further, transducer performance is validated by performing with real samples. The results suggested that the fabricated flexible PTS transducer with superior electrocatalytic activity, stability, and low response time can be explored for the sensing of neurotransmitters and hence can be exploited at in vitro and in vivo conditions for the early detection of the various diseases