Studies on the electrochemical and dopamine sensing properties of AgNP-modified carboxylated cellulose nanocrystal-doped poly(3,4-ethylenedioxythiophene)

Carboxylated cellulose nanocrystals (CNCC) were synthesized by treating microcrystalline cellulose with ammonium persulfate. Silver nanoparticles (AgNPs) were prepared on the surface of CNCC using NaBH 4 as reductant. Novel conducting nanocomposites of poly(3,4-ethylenedioxythiophene) (PEDOT) doped with AgNPs/CNCC were electrodeposited on the surface of the glassy carbon electrode. The nanocomposites prepared in various ratios of PEDOT, CNCC, and AgNPs were characterized by scanning electron microscopy, transmission electron microscope, electrochemical impedance spectroscopy, cyclic voltammetry, and differential pulse voltammetry. The prepared PEDOT/AgNPs/CNCC showed much low electrochemical impedance and very good response towards the oxidation of dopamine. Based on these findings, a highly stable, sensitive, and selective amperometric sensor for the detection of dopamine was developed. Operated at 0.20 V (vs. Ag/AgCl), the sensor can detect dopamine in the range of 0.05 to 782 μM with a 17-nM detection limit.