A dual-channel fusion sensing platform of multicolor polyaniline visual and self-powered photoelectrochemical detection of mcirocystin-RR

The focus of this work was to develop a novel dual-channel platform based on the multi-color electrochromic visualization and self-powered photoelectrochemical sensors for detection of microcystin-RR (MC-RR). On the one hand, utilizing the inhibited output performance of the sensing platform by MC-RR which was captured by the aptamer, the MC-RR concentration was quantified via the short-circuit current (Isc) value of the proposed sensing platform. On the other hand, the transfer of photoelectrons produced by the g-C3N4/ZnIn2S4 photoanode to the modified polyaniline (PANI) photocathode produced a multi-color change from bluish violet to yellowgreen, which was used to achieve visual signal readouts. Under optimal conditions, the Isc and the average color channel values showed a linear relationship with the logarithm of MC-RR concentration in the range of 104 - 102 nM and 5 x 10-4 - 102 nM, with the detection limits of - 3.3 x 10-5 nM and - 1.7 x 10-4 nM (S/N = 3), respectively. Meanwhile, the proposed dual-channel visualized self-powered platform had excellent reproducibility and stability, providing a prototype for the detection of MC-RR in real samples. The proposed sensing platform not only provided the diversity of signal readouts, but also enhanced the reliability and accuracy of the detection.