Novel self-powered anti-interference photoelectrochemical sensor via zirconium porphyrin-based metal–organic framework as multifunctional signal label for oxytetracycline detection in food and environment

[Display omitted] •A novel self-powered PEC sensor was constructed for the detection of oxytetracycline (OTC).•Zirconium porphyrin-based metal–organic framework (ZPM) as multifunctional signal label is aimed to amplify signal.•The sensor combines excellent photoelectric performance of photoanode and anti-interference of photocathode sensing.•The developed PEC sensor has high sensitivity for detecting OTC in food and environment. As a newly developed sensing mode, self-powered PEC sensing may successfully address issues like individual photoanode or photocathode sensing with poor signal responsiveness and weak anti-interference capacity. Herein, a self-powered PEC sensor was developed to detect oxytetracycline (OTC) by integrating SnS2/Sb2S3 photoanode with Cu2O photocathode, and zirconium porphyrin-based metal–organic framework (ZPM) as multifunctional signal label to achieve signal amplification. The highly efficient and stable self-powered biosensor not only delivers a sustained and robust photocurrent response for bioanalysis, thanks to its well-designed stepped band structure, but also successfully mitigates interference from reducing agents. Furthermore, the ZPM was firstly used as a multifunctional nano label in PEC biosensing platform. On the one hand, the ZPM has a large specific surface area and abundant functional groups that can be used to immobilize the aptamer. On the other hand, because of steric hindrance, poor conductivity, competition for dissolved oxygen and light source with the substrate, the ZPM can as photocathode quenching source to affect the photocurrent response. In optimized experimental conditions, the fabricated PEC sensing platform showed a broad linear range of 0.1 pM to 100 nM for assay of OTC with a low limit of detection (LOD=0.03 pM), coupled by its quantification in human serum samples with acceptable results. This work provides an avenue for the development of high-performance photoelectrochemical materials and opens up the possibility of designing more sensitive self-powered PEC biosensors.