▎ 摘　　要

Herein, construction of an ecofriendly SnO2 nanoparticles@bioconjugated reduced graphene oxide' nanocomposite was reported, which was prepared through carbodiimide coupling between carboxyl groups of amino acid 'L-proline' and amino-functionalized reduced graphene oxide (H2N-rGO) followed by its anchoring to SnO2 nanoparticles. Furthermore, prepared nanocomposite modified electrode was applied for the selective and sensitive detection of cadmium (II) in water sample. Synergistic effect of SnO2 and bioconjugated reduced graphene oxide greatly enhanced the electrocatalytic efficiency of the electrode. Quantification of Cd (II) was recorded in a linear range of 0.001-0.4 ppm with limit of detection 1 x 10(-4) ppm and high sensitivity 67.43 mu A/ppm. Finally, real sample analysis was also performed using tap water and ground water samples with excellent recovery results.