A smartphone-controlled portable multiplexed photoelectrochemical sensor based on dual UV intelligent response system-assisted signal resolution strategy

Portable multiplexed photoelectrochemical (PEC) sensor is essential for on-site detection of multiple targets in complex environment. However, the evolution of portable multiplexed PEC sensor is still constrained by specialized instruments and complex multi-interface modification steps, etc. In this work, we design a UV-assisted multiple signals resolution strategy and construct a smartphone-controlled portable multiplexed PEC sensor. Specifically, following the dual-target biorecognition, UV light triggers the cleavage of photo-responsive DNA so that the dual DNA signal labels can be separated. When the signal label (first target) attaches to the azobenzene-covalently bound DNA (Abz-DNA) and triggers HCR on the electrode surface, UV light illumination induces the structure change of azobenzene, resulting in the detachment of Abz-DNA/HCR complex from the electrode surface. After reincorporation of fresh Abz-DNA, the reconstituted photoelectrode can be reused for the second target analysis. The feasibility of the sensor is validated through the simultaneous detection of two co-existing mycotoxins in corn. Notably, the UV-meditated signal discrimination strategy and smartphone-displayed multi-photocurrent readout enable the portability of the PEC sensor, making it possible for in-situ monitoring of environmental safety and food quality.