An ultra-low fouling electrochemical mocularly imprinted sensor based on size exclusion effect for highly selective pentachlorophenol detection

Pentachlorophenol (PCP) is considered as a highly toxic pollutant in water environment. However, detecting low concentrations of PCP precisely hindered by various interferences is still a tough challenge. In this study, an antifouling electrochemical molecularly imprinted (E-MIP) sensor harnessing the size exclusion effect was specifically designed for highly selective detection of PCP in water. The distinctive interaction between the size-selective poly-hydroxyproline helical peptide (PHHP) and poly(o-phenylenediamine) (p(o-PD)) molecularly imprinted films, strongly reduced non-specific adsorption. In the face of high concentrations of organic matters and ions, the reported sensor exhibited robust antifouling capabilities that it preserved 90 % of the initial signal. In addition, the limit of detection (LOD) reached an exceptionally low level of 1.13 nM (S/N = 3), spanning a wide linear range from 1 nM to 10 μM, and the sensor showed high selectivity with an impressive imprinted factor of 12.01 for PCP. Meanwhile, it owned great repeatability and reproducibility, long-term stability for PCP detection within 25 days, and decent reusability (retaining 92.33 % of its senor performance after 5 cycles), which ensured its excellent feasibility for determination of PCP in complex water samples with co-existing interferences due to acceptable recoveries. The development of this strategy provides an innovative platform for PCP quantification in real water samples, underscoring its potential as a key tool in managing PCP at relevant sites.