A metal-free and preconcentration-free method for non-enzymatic amperometric determination of pentachlorophenol using...

An enzyme-free, metal-free, and preconcentration-free electrochemical sensor for pentachlorophenol assay has been fabricated. The interface of the sensor is based on a hollow zeolitic imidazolate framework-derived mesoporous carbon material (denoted as HZC/SPCE). The sensor exhibits linear amperometric response upon pentachlorophenol at 0.82 V (vs. Ag/AgCl) in the concentration range 0.001 to 26.8 mg L^-1 (3.75 × 10^-8~1.006 × 10^-4 M) (R² = 0.997). The sensitivity of HZC/SPCE is 3.53 × 10² μA mM^-1 cm^-2 with a detection limit of 2.05 × 10^-9 M (S/N = 3) for pentachlorophenol. The method has been applied to the determination of pentachlorophenol in spiked food packaging samples with recoveries in the range 92.0 to 107.0%. Graphical abstract Schematic representation of the synthesis of hollow ZIFs-derived hollow carbon material. Free protons derived from tannic acid penetrated into ZIF-8 to destroy its solid framework and the outer parts covered by tannic acid were protected from further etching. After pyrolysis, the morphology of HZC remained similar to that of HZIF-8. Abbreviation: CTAB: hexadecyl trimethyl ammonium bromide; Melm: 2-methylimidazole; ZIF-8: zeolitic imidazolate framework-8; TA: tannic acid; HZIF-8: hollow zeolitic imidazolate framework-8; HZC: hollow zeolitic imidazolate frameworks (ZIFs)-derived mesoporous carbon material.