Molecular Imprinting Polymer Nanoparticles Coupled with an Optical Sensor for Sensitive and Label-Free Detection of p-Cresol

Selective detection of toxic pollutants present in waterhas beena severe challenge to the scientific community for a long time. Thenoble integration of optical fiber-based interferometry with a bio-recognizingelement molecular imprinting polymer (MIP) exhibits a promising techniquefor selective and susceptible biochemical detection. Here, we reporta compact, stable, reproducible, and label-free optical sensor usinga combined approach of photonic crystal fiber (PCF)-based modal interferometryand MIP nanoparticles (MIP-NPs) for selective detection of water pollutant p-cresol with an extremely low limit of detection (LOD).The MIP-NPs having a greater surface-to-volume aspect ratio allowsmore target analytes to bind. The sensor immobilized with MIP-NPsshows unprecedented sensitivity of 1.865 x 10(8) nm/Mwith specific and repeatable detection performance for a broad dynamicdetection range of 10(-8)-10(-3) M. The sensor offers a remarkable detection ability of as low as1.55 nM concentrations of p-cresol in the aqueousmedium, for water quality monitoring. Fast response, high resolution,compact size, label-free broad detection range, and selective reusableperformance of the proposed sensor exhibit potential for board practicalutilizations, including medical sectors, online and remote biosensing,and water resource monitoring.

Automated summary

Selective and susceptible biochemical detection of toxic pollutants in water has long been a challenging task for the scientific community. In this study, a compact, stable, reproducible, and label-free optical sensor using photonic crystal fiber-based modal interferometry and molecular imprinting polymer nanoparticles (MIP-NPs) is developed for the selective detection of p-cresol pollutant in water. The sensor exhibits a remarkable detection ability with an extremely low limit of detection and a broad dynamic detection range.