A novel photoelectrochemical microfluidic immunosensor for the ultrasensitive detection of PlGF based on ZnIn2S4/In2S3 heterojunction material modification

Preeclampsia constitutes a critical and severe complication of gestational hypertension in pregnant women. At present, there exists no effective treatment for preeclampsia, although placental growth factor (PlGF) has been identified as the most reliable predictive biomarker. Consequently, the accurate quantification of PlGF levels in the blood of pregnant women affected by preeclampsia is imperative. In this study, a microfluidic photoelectrochemical immunosensor based on ZnIn 2 S 4 /In 2 S 3 heterojunction photosensitive material was developed on fluorine-doped tin oxide (FTO) and integrated with microfluidic channels. This innovative platform enables the detection of PlGF, an eclampsia marker, in pregnant women. Following activation with chitosan (CTS) and glutaraldehyde (GA), the immobilized monoclonal antibody specific to PlGF forms a covalent bond with its corresponding antigen, and the interaction is detected through changes in photocurrent. The experimental results indicate that the proposed sensor exhibits a wide detection range of 0.1   pg   mL⁻¹ to 1   µg   mL⁻¹ for PlGF, with a limit of detection (LOD) of 0.0879   pg   mL⁻¹ (S/N = 3). Additionally, the sensor demonstrates excellent specificity, stability, reproducibility, low sample consumption, and robust detection performance for clinical specimens. Therefore, this sensor holds significant promise as an auxiliary diagnostic tool for early screening of eclampsia-related conditions in pregnant women.