One-step voltammetric deposition of l-proline assisted silver nanoparticles modified glassy carbon electrode for electrochemical detection of hydrogen peroxide

l -proline assisted silver nanoparticles were electrodeposited on glassy carbon electrode by one-step voltammetry method. The results of Raman spectroscopy, X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy confirmed a uniform distribution of nanometer sized silver nanoparticles in the presence of l -proline and the formation of mixed silver oxides in the absence. l -proline as a stabilizer plays the very important role in slowing the oxidation of metallic silver and makes contributions to avoid aggregations. More importantly, l -proline caused nearly 200   mV potential shifted towards less negative potential and almost two-fold sensitivity increased. This low-cost and simple silver nanoparticles sensor is not only free from various disadvantages of enzyme or noble based sensors, but also provides a superior sensing performance for electrochemical detection of hydrogen peroxide. The resultant silver nanoparticles stabilized using l -proline displayed lower detection limit of 0.05   μM, larger detection linear range from 0.1   μM to 5145   μM, and higher selectivity in the presence of interfering species such as ascorbic acid , uric acid , l -glucose, glycine and lactose, for H 2 O 2 detection, relative to silver nanoparticles without l -proline. These comprehensive characterizations attribute the excellent H 2 O 2 electrocatalytic performance to its fast electron transfer kinetics of the metallic silver (Ag 0 ) in l -proline stabilized silver nanoparticles. The fabricated sensor also reliably applied in detection of H 2 O 2 in milk samples. This work suggests the l -proline assisted silver nanoparticles are promising materials for highly active and selective non-enzymatic H 2 O 2 detection.