[Journal of Electroanalytical Chemistry] Continuous electrochemical detection of hydrogen peroxide b
We developed electrochemical microfluidic devices containing Au-Ag bimetallic nanoparticles on single-walled carbon nanotube (SWCNT) electrodes for precise, rapid and non-enzymatic electrochemical detection of hydrogen peroxide (H2O2). A homogeneous SWCNT layer on a glass substrate was patterned by a standard photolithography method and an O2-plasma technique. The patterned SWCNT layers were used as working electrode, counter electrode, and reference electrode in a 1 mm wide and 23 μm deep microchannel. To enhance the electrochemical catalytic properties of the working electrode, Au covered Ag nanoparticles (NPs) were electrochemically deposited on the SWCNT working electrode with current streaming solution into a microfluidic channel. The AgNPs had catalytic activity to improve the reduction of H2O2combined with AuNPs, which could support catalytic reaction of AgNPs. The reduction in H2O2 in fabricated devices was monitored at an optimized condition and was linear with H2O2 concentration, resulting in a sensitivity of 13.1 μA·cm− 2·mM− 1, a correlation coefficient of r2 = 0.985, and limit of detection 26.8 μM (S/N = 3). For the analysis of real samples, diluted antiseptic solutions containing 3 wt% H2O2 were used to determine the concentration of H2O2 in the pharmaceutical sample. The recovery values ranged from 97% to 107%, and relative standard deviations were below 5%. We expect that the developed microfluidic sensor is a prospective electrochemical platform for accurate, reproducible non-enzymatic detection of H2O2.
Euna Ko, Van-Khue Tran, Yanfang Geng, Woo Sung Chung, Chan Ho Park, Min Ki Kim, Ga Hyun Jin, Gi Hun Seong, Department of Bionano Engineering, Hanyang University, Ansan 426-791, South Korea Received 18 November 2016, Revised 9 March 2017, Accepted 13 March 2017, Available online 14 March 2017 http://dx.doi.org/10.1016/j.jelechem.2017.03.027