Fiber-optic SPR sensor based on molecularly imprinted polymers for detection of perfluorooctane sulfonate in water

A novel MNM fiber SPR sensor integrated with APTES-modified MIPs is developed for highly specific PFOS recognition. • PFOS LoD is 0.84 pg/mL over concentration range of 1 pg/mL to 10 ng/mL. • Validated detection to spiked PFOS in tap and lake water with recover rates of 79.00% ~114.70%. 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. Download: Download high-res image (143KB) Download: Download full-size image