A novel design thia-bilane structure-based molecular imprinted electrochemical sensor for sensitive and selective dopamine determination

Abstract

Synthesis of specific and functional novel monomers for molecular imprinting-based vital biomedical applications has attracted great attention. In the current study, organic synthesis of a new functional thia-bilane structure (S-BIL) and the sensor performance of electrochemically formed molecular imprinted polymer (pS-BIL MIP) deposited on pencil graphite electrode (PeGE) were demonstrated. The synthesis of monomer S-BIL was carried out by the addition reaction of tripyrrane 1 to nitrovinyl thiophene 2 in the presence of molecular iodine. The resulting monomer was purified by using flash column chromatography and characterized by 1H NMR, 13C NMR and HRMS techniques. Afterwards, dopamine (DA) was embedded into the polymeric structure during the facile electropolymerization of the S-BIL monomer. Methods such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and contact angle measurement were used for the characterization of the MIP electrode. Under the optimal conditions, pS-BIL MIP electrode showed a very good linearity for dopamine in the concentration range of 0.05 μM to 250 μM and a low limit of detection (LOD), 20 nM (n = 3). These results were compared with the response of the non-imprinted polymer modified electrode (NIP) and unmodified electrode. Prominent throughputs were accomplished with the pS-BIL MIP PeGE. The MIP electrode was tested in the presence of various interferents such as urea, tryptophan, ascorbic acid and glucose. This specifically designed monomer for electrochemical molecular imprinting technology contributes to outstanding sensor performances including high sensitivity and selectivity, good stability, reproducibility and robustness.