A molecularly imprinted electrochemical sensor based on in-situ polymerization for rapid and selective detection of tonalide in aqueous environment.

Given the adverse effects of tonalide (AHTN) on aquatic organisms and humans, coupled with the limitations of current detection methods, which are time-consuming, require expensive equipment and complicated sample preparation procedures, there is a clear need to develop a new technique for detecting AHTN that is highly sensitive, rapid, cost-effective and efficient. In this study, a new simple electrochemical sensor for the determination of AHTN in aqueous environments was developed for the first time through the in-situ polymerization of an AHTN-imprinted polymer on the surface of a graphene (G)-modified carbon electrode (GCE). Following a series of comparative tests, including cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), the novel AHTN molecularly imprinted sensor (AHTN-MIP/G/GCE) has been demonstrated to be an effective tool for monitoring AHTN. The results demonstrate that the linear detection range of the current response of the AHTN-MIP/G/GCE electrode to AHTN was 0.01 μM-4 μM (i.e., 2.584 μg/L-1033.6 μg/L), with a detection limit of 2.3 × 10⁻⁹ M (i.e., 594.32 ng/L), following the optimization of the experimental conditions. Furthermore, the new sensor was successfully employed for the detection of AHTN in water samples, with recoveries of 97.1%-108.2 % with the added standards. Consequently, the new electrochemical sensor demonstrated good stability and acceptable reproducibility. This study provides a new method for the future detection of AHTN in the aqueous environment.