Electrostatic-driven solid phase microextraction coupled with surface enhanced Raman spectroscopy for rapid analysis of pentachlorophenol

Abstract

Pentachlorophenol (PCP) is a very high toxicity and slowly biodegraded organic pollutant. People may be exposed to PCP in environmental media through the inhalation of contaminated air, and ingestion of water and hazardous waste. Even low PCP intake will have serious effects on renal, metabolic and neurological functions, particularly in terms of carcinogenicity. Here, an electrostatic interaction driven solid phase microextraction (SPME) combined with surface enhanced Raman spectroscopy (SERS) was proposed for rapid detection of PCP in environmental water. The nanoporous Ag coating was in-situ electrochemically synthesized and modified by cysteamine to form a positive stationary phase on a fiber surface. The PCP was extracted using the DI-SPME mode and its SERS spectra were investigated; the characteristic bands at 338 cm⁻¹, 378 cm⁻¹ and 480 cm⁻¹ were identified as the fingerprint peaks. The extraction procedure was optimized, and the adsorption mechanism was also discussed by the electric double layer model. The good stability and uniformity of the substrate provide a high enhancement factor of 3.7 × 10⁵ and low LOD of 6.4 × 10⁻⁹ M for quantitative determination. This work provides a versatile strategy for rapid on-site detection of ionic or polar organic pollutants in environmental media.