Preparation of octyl-modified silica isoporous membrane for hydrophobic enrichment and electrochemical detection of methylmercury in aquatic products.

Methylmercury (CH3Hg+), a lipophilic environmental pollutant, accumulates in fish, shellfish, and other organisms, posing significant risks to human health through the food chain. Developing a convenient and sensitive analytical method for CH3Hg+ detection is crucial for reducing costs and enhancing the efficiency of food safety testing. In this study, we prepared an octyl-modified silica isoporous membrane on the indium tin oxide (ITO) electrode (Octyl-SIM/ITO) via the electrochemical-assisted self-assembly (EASA) method using octyltrimethoxysilane (O-TES) as the functional organosilane. The Octyl-SIM/ITO electrode exhibits vertically-ordered nanochannels and strong hydrophobic affinity, enabling selective penetration and enrichment of weakly polar analytes. Utilizing square wave anodic stripping voltammetry (SWASV), the Octyl-SIM/ITO electrode demonstrates superior electrochemical response signals for CH3Hg+ detection, achieving a detection limit as low as 4 nM. This method allows for accurate and reproducible detection of CH3Hg+ in fish and oyster samples with minimal sample preparation, offering promising potential for portable in situ detection.