A label-free microfiber biosensor for auxiliary diagnosis of pre-eclampsia

Pre-eclampsia (PE) is a serious multiorgan complication that can seriously threaten the life and health of pregnant women and their fetuses. Current clinical diagnosis relies heavily on nonspecific symptoms, while conventional biomarker assays lack the sensitivity to detect low concentrations of placental growth factor (PlGF), a key indicator whose levels drop significantly as PE progresses. This paper proposed a cascade microfiber (CMF) biosensor that utilizes the vernier effect for the quantitative detection of PlGF in clinal serum samples of PE patients. The experimental results show that the proposed CMF biosensor has a limit of detection as low as 0.49 pg/mL and a detection time that is less than 20 min. Clinical validation using serum samples from 35 pregnant women demonstrated that the CMF biosensor achieved 78.6% sensitivity, 85.7% specificity, and 82.9% diagnostic accuracy. Importantly, we have established a strong correlation between PlGF levels and clinical severity, confirming the biomarker’s auxiliary diagnosis value and reinforcing the sensor’s clinical relevance. The proposed method could form the basis of a next-generation diagnostic system for PE that combines high sensitivity, speed, and simplicity and has the potential to transform current screening protocols by enabling early intervention and improving maternal–fetal outcomes.