A Composite Structure of Modified Silver Nanoparticles for Improving the Recognition Performance of Electrode

To meet the demand for rapid detection of methylene blue residues in aquatic products, this study constructed a composite structure modified with silver nanoparticles on the surface of a glassy carbon sheet for precise detection. This composite film used the synergistic effect of the composite structure, which significantly enhanced the current response between the composite film and MB. The CV and EIS results demonstrated that this composite structure exhibited outstanding performance, endowing the composite film with the capability for sensitive detection of methyl blue. The results showed that the composite film detected methylene blue by differential pulse voltammetry, with a limit of detection as low as 1.6 nM. In the concentration range of 10 nM to 120 nM, the current intensity presented a good linear relationship with the concentration of MB. In addition, this composite film successfully identified methylene blue in aquatic products, with a recovery rate ranging from 81% to 113%. The results indicated that the composite film could be effectively applied to the sensitive detection of methylene blue in complex samples. This study provided a reliable and easy-to-construct electrochemical sensing platform for aquatic product safety monitoring.