Electrocatalysis Oxidation of GMP Based on Layered Double Hydroxide Functionalized with Anionic Surfactant and Room Temperature Ionic Liquid Modified Glassy Carbon Electrode

摘要

The electrocatalysis oxidation of guanosine-5'-monophosphate (GMP) was investigated on Mg-Al layered double hydroxide (LDH) functionalized with sodium dodecyl sulfate (SDS) and room temperature ionic liquid (RTIL)modified glass carbon electrode (GCE). The cyclic voltammogram of GMP on the modified electrode (RTIL/LDH-SDS/GCE) exhibited a well defined anodic peak at 1.091 V in 0.2 mol·L-1 pH 4.4 acetate buffer solution. The GMP oxidation was enhanced in the presence of anionic surfactant in the films. The results suggest that the surfacrant molecules intercalate the LDH layers to preconcentrate GMP molecules and the RTIL showed good ionic conductivity. The experimental parameters were optimized, the kinetic parameters were investigated and the probable oxidation mechanism was proposed. Under the optimized conditions, the oxidation peak current was proportional to GMP concentration in the range from 5.0× 10-7 to 1.0× 10-4 mol·L-1 with the correlation coefficient of 0.9987and the detection limit was 1.0 × 10 7 mol·L-1. The RTIL/LDH-SDS/GCE showed a good electrochemical response to the oxidation of GMP and would be developed into a new biosensor.