Direct detection of Pb²⁺ and Cd²⁺ in juice and beverage samples using PDMS modified nanochannels electrochemical...

Direct electrochemical detection in real food samples remains challenging due to the fouling and interference by abundant interference components. Herein, we report an electrochemical sensing platform based on binary assembly of silica nanochannels and polydimethylsiloxane that is able to detect Pb²⁺ and Cd²⁺ in real food samples without complex pretreatments. Using differential pulse anodic stripping voltammetry, the electrochemical detection consists of electro-deposition of metal species and subsequent anodic stripping in the modified silica-nanochannels. Under the optimized conditions, the linear ranges were obtained from 4 to 1500 μg L^-1 for Pb²⁺ and 30 to 900 μg L^-1 for Cd²⁺. The relative standard deviations were 2.9% and 3.6% for Pb²⁺ and Cd²⁺ of 300 μg L^-1. Without tedious pretreatments, the quantitative detection of Pb²⁺ and Cd²⁺ in real juice and beverage samples was successfully performed, revealing that the developed sensor possesses excellent anti-interference and practicability properties for unprocessed food.