Self-assembly of alkyldithiols on a novel dendritic silver nanostructure electrodeposited on a stainless steel wire as a fiber coating for solid-phase microextraction

Abstract

A facile and efficient electrodeposition approach for the controllable preparation of dendritic silver nanostructure was developed on an etched stainless steel (ESS) wire. Subsequently, self-assembled of alkyldithiols (HS–C_x–SH, x = 2, 3, 6, 8) was performed on the dendritic Ag coating via Ag–S bonding. The octanedithiol modified Ag nanodendrites (AgNDs) coated ESS fiber (HS–C₈–S–AgNDs/ESS) was then assessed for SPME of polycyclic aromatic hydrocarbons (PAHs), ultraviolet (UV) filters, polychlorinated biphenyls (PCBs), chlorophenols (CPs), phthalate esters (PAEs) and substituted anilines coupled to high-performance liquid chromatography with UV detection (HPLC-UV). This fiber exhibits higher extraction capability and good selectivity for PAHs, UV filters, PCBs and triclosan compared to CPs, PAEs and substituted anilines. In particular, the microextraction conditions were investigated and optimized for SPME performance of UV filters. Under the optimized conditions, the developed method showed good linearity between 0.30 and 400 μg L⁻¹ with corresponding correlation coefficients in the range of 0.9973–0.9986. The limits of detection ranged from 0.05 to 0.12 μg L⁻¹. The relative standard deviation for fiber-to-fiber reproducibility of five fabricated fibers in the same batch was less than 8.2%. The expanded uncertainties were below 6.9% (coverage factor k = 2). The developed method was practically applied to the preconcentration and determination of trace UV filters from real environmental water samples.