A smartphone-assisted photoelectrochemical POCT method via Z-scheme CuCo2S4/Fe3O4 for simultaneously detecting co-contamination with microplastics in food and the environment.

As emerging contaminants, microplastics threaten food and environmental safety. Dibutyl phthalate (DBP, released from microplastics) and benzo[ a ]pyrene (BaP, adsorbed on microplastics) coexisted in food and the environment, harming human health, requesting a sensitive and simultaneous testing method to monitor. To address current sensitivity, simultaneousness, and on-site portability challenges during dual targets in complex matrixes, CuCo 2 S 4 /Fe 3 O 4 nanoflower was designed to develop a smartphone-assisted photoelectrochemical point-of-care test (PEC POCT). The carrier transfer mechanism in CuCo 2 S 4 /Fe 3 O 4 was proven via density functional theory calculation. Under optimal conditions, the PEC POCT showed low detection limits of 0.126, and 0.132 pg/mL, wide linearity of 0.001–500, and 0.0005–50 ng/mL for DBP and BaP, respectively. The smartphone-assisted PEC POCT demonstrated satisfied recoveries (80.00%–119.63%) in real samples. Coherent results were recorded by comparing the PEC POCT to GC–MS (DBP) and HPLC (BaP). This novel method provides a practical platform for simultaneous POCT for food safety and environment monitoring. A smartphone-based photoelectrochemical point-of-care test biosensor was developed for the simultaneous detection of dibutyl phthalate (DBP, released from microplastics) and benzo[ a ]pyrene (BaP, adsorbed on microplastics) in food and environmental samples using Z-scheme CuCo 2 S 4 /Fe 3 O 4 as highly effective photoelectric materials. [Display omitted] • Construction of a smartphone-assisted photoelectrochemical point-of-care test platform. • Simultaneous detection of DBP (released from microplastics) and BaP (adsorbed on microplastics). • Verification of the Z-scheme transfer pathway of CuCo 2 S 4 /Fe 3 O 4 nanocomposites. • Detection of dual-targets in complex food and environment matrixes. [ABSTRACT FROM AUTHOR]