Smartphone Dual-Channel Biosensor for Simultaneous PLGF/sFlt-1 Detection and Signaling Pathway Analysis

Preeclampsia in pregnancies affects angiogenesis while the fetus develops. Early diagnosis of preeclampsia can enable timely prognosis and intervention. This study developed a smartphone-based, label-free dual-channel electrochemical biosensing platform for the simultaneous detection of preeclampsia biomarkers, placental growth factor (PLGF) and soluble Fms-like tyrosine kinase-1 (sFlt-1). Based on the functional modification of gold nanoparticles and reduced graphene oxide on working electrodes, the specific surface area is enlarged, and the stability is improved. PLGF and sFlt-1 antibody serving as sensitive elements, are immobilized on the electrode surface. As PLGF binds sFlt-1 dynamically, fluidic chambers are designed based on 3D printing for comprehensive detection. The biosensor achieved linear ranges of 10-8000 pg mL^-1 for sFlt-1 and 1-250 pg mL^-1 for PLGF, meeting clinical diagnostic requirements. Molecular docking is used to analyze the binding properties and signaling pathways of PLGF and sFlt-1, providing critical diagnostic insights for clinicians. This biosensing platform, featuring a portable integrated circuit and smartphone-based APP, enables point-of-care testing (POCT). Comparison tests using plasma samples from 10 individuals demonstrated a strong correlation (r > 0.98, p > 0.1) with ELISA, indicating the potential in clinical POCT applications for preeclampsia. These results suggest that the sensor can be used as a dual-channel biomarker for preeclampsia without sample labeling.