Electrochemical Determination of Hydrazine at Gold and Platinum Nanoparticles Modified Poly(L-Serine) Glassy Carbon Electrodes

L-serine monomer was polymerized electrochemically on a glassy carbon electrode by cyclic voltammetry. After L-serine polymerization, gold and platinum metal nanoparticles were doped by electrochemical reduction on the surface. The modified electrodes were characterized by using scanning electron microscopy and electrochemical impedance spectroscopy. The electrochemical behavior of hydrazine oxidation at the electrodes was investigated in 0.1M pH 7.0 phosphate buffer. Hydrazine oxidation peaks were observed at 650, 399, 280, and -395mV at the bare glassy carbon, poly(L-serine) modified glassy carbon, gold nanoparticle modified poly(L-serine) film glassy carbon electrode, and platinum nanoparticles modified poly(L-serine) film glassy carbon electrode, respectively. The most active surface towards hydrazine oxidation was the platinum nanoparticle modified poly(L-serine) film glassy carbon electrode with a 1045mV negative potential shift and approximately three-fold higher peak current. The hydrazine oxidation peak was shifted to a 370mV negative potential with a 2.5 times higher current at the gold nanoparticle modified poly(L-serine) film glassy carbon electrode compared to the bare electrode. The linear concentration ranges were from 1.0 to 1000 mu M and 0.5 to 1000 mu M for the gold nanoparticle modified poly(L-serine) film glassy carbon and the platinum nanoparticles modified poly(L-serine) film glassy carbon electrodes with limits of detections of 0.5 and 0.2 mu M, respectively.