Abstract: Methanobactin-functionalized gold nanoparticles (Mb-AuNPs) were prepared based on the ability of Mb to capture copper ions in the environment and the signal amplifying function of AuNPs. Stripping voltammetry with an Mb-AuNPs-modified electrode could specifically detect Cu2+. Under the optimal conditions, the peak current response showed a good linear relationship with logarithmic copper ion concentration in the range of 10 nmol/L–100 μmol/L with a correlation coefficient of 0.960 09 and the detection limit was 1.15 nmol/L at a signal-to-noise ratio of 3. Accordingly, the new electrochemical method established in this study had high sensitivity and stability, which will provide theoretical basis for the detection of copper irons in foods in the future.

Key words: methanobactin; gold nanoparticles; stripping voltammetry; copper ions