Target-induced in situ competitive absorption: A new strategy for photoelectrochemical aptasensing towards zearalenone based on CdS/ ethylenediamine 3D nanowires network with sulfur vacancies

Zearalenone (ZEN), as one of the highly important fungal toxins, possesses adverse effects on human health, so there is vitally significant to seek sensitive and effective methods for ZEN analysis. Here, we present a novel photoelectrochemical (PEC) aptasensor for the detection of ZEN, by designing an in-situ light competitive absorption process on the photoactive substrate. To achieve this, the three-dimensional CdS/ethylenediamine nanowires network (3D CdS/EDA NWN) was synthesized as an ideal photo-sensitive material. The unique structure of the 3D nanowires network of CdS/EDA NWN, along with its rich sulfur vacancies and self-contained electronic donor, makes it highly suitable for the anchoring of biomolecular recognition units and favorable for photo-electric conversion. Additionally, ZEN-aptamer linked MoS2 quantum dots (MoS2 QDs) were introduced by ZEN recognition and utilized as effective signal quencher. The ZEN induced in-situ competitive light absorption between MoS2 QDs and photoactive substrate leads to a decrease in the original PEC signal, resulting in enhanced detection sensitivity. The constructed PEC aptasensor exhibited a linear range from 0.1 pg mL-1 to 100 ng mL-1, and a relatively low detection limit of 0.024 pg mL-1 (S/N = 3), as well as high stability, selectivity, and practicability. This work gives novel ideas for the design of photosensitive materials and offers a neoteric approach for the detection of other environmental pollutants.