Study on Cd2+ Determination Using Bud-Like Poly-L-Tyrosine/Bi Composite Film Modified Glassy Carbon Electrode Combined with Eliminating of Cu2+ Interference by Electrodeposition

A bud-like poly-L-tyrosine/Bi modified glassy carbon electrode (p-Tyr/Bi/GC) was prepared by CV and in situ Bi plating, whose conductivity and membrane morphology were characterized by CV, EIS and SEM, respectively. The p-Tyr membrane can effectively promote the enrichment of Cd2+. The optimal Tyr concentration and scanning number for p-Tyr/GC preparation were 2.0 mmol . L-1 and 35, while the optimal Bi3+ concentration, pH and Cd2+ accumulation potential in test medium were 3.0 mu mol . L-1, 6.5 and -1.3 V, respectively. The linear equation of p-Tyr/Bi/GC's response to Cd2+ (1.0 nmol . L-1 to 2.0 mu mol . L-1) was i(p) (mu A) = -0.6809 + 100.2c (mu mol . L-1) (R-2 = 0.9985) with a detection limit of 0.11 nmol . L-1 (3S/N). The elimination of interference caused by Cu2+ in sample was studied by electrodeposition. The p-Tyr/Bi/GC electrode was successfully used for detecting Cd in rice samples with good reliability and accuracy. The developed Cd2+ sensor exhibits high sensitivity, wide linear range and low detection limit, especially the designed method of eliminating Cu2+ interference has the characteristics of high selectivity, simple operation and wide application range.

Automated summary

A bud-like poly-L-tyrosine/Bi modified glassy carbon electrode was prepared for enriching Cd2+ with high sensitivity, wide linear range, and low detection limit. The developed sensor successfully detected Cd in rice samples with good reliability and accuracy, while effectively eliminating interference caused by Cu2+. The method shows high selectivity, simplicity in operation, and wide application range.