Perfluorooctane sulfonate (PFOS) is a persistent organic pollutant widely present in aquatic environments, posing a severe risk to human health due to its bioaccumulation and toxicity. To address the urgent need for sensitive on-site detection of PFOS, this study developed a fiber-optic surface plasmon resonance (SPR) sensor based on a multimode-no-core-multimode fiber structure. By immobilizing PFOS- selective molecularly imprinted polymers (MIPs) onto the gold surface, the sensor achieved good sensitivity and long-term stability. Experimental results show that the proposed sensor has an ultra-low limit of detection (LoD) of 0.84 pg/mL and a wide dynamic linear measurement range from 1 pg/mL to 10 ng/mL (R 2 = 0.9933), outperforming most reported optical/colorimetric PFOS sensors. Furthermore, the sensor exhibited excellent selectivity, satisfactory repeatability (relative standard deviation = 4.63%), and good practical applicability, requiring only simple filtration pretreatment to achieve spiked recovery rates of 79.00%–114.70% in tap and lake water samples. These results highlight the sensor's great potential for on-site PFOS monitoring in complex aquatic environments.
Wu et al. (2026) studied this question.