▎ 摘　　要

Poly(diallydimethylammonium chloride) functionalized graphene/double-walled carbon nanotube composite (PDDA-GN/DWCNT) was synthesized by a facile microwave-assisted reduction reaction. PDDA-GN/DWCNT exhibits enhanced electrocatalytic activity towards nitrite oxidation. The direct electrooxidation behaviors of nitrite on PDDA-GN/DWCNT were investigated by cyclic voltammetry, amperometric i-t curve, and rotating disk electrode experiments. Under the optimum conditions, PDDA-GN/DWCNT was applied to the quantitative analysis of nitrite with a wide linear range covering 0.07-3000 mu M and a low detection limit of 0.03 mu M (S/N=3). Moreover, PDDA-GN/DWCNT exhibits satisfied results in the determination of nitrite that released from breast cancer cells.