Highly sensitive nonenzymatic glucose and H2O2 sensor based on Ni(OH)2/electroreduced graphene oxide--multiwalled...

In this article, a nonenzymatic sensor based on Ni(OH)2/electroreduced graphene oxide (ERGO)-multiwalled carbon nanotube (MWNT) nanocomposites is fabricated via convenient electrodeposition of Ni(OH)2 nanoparticles on ERGO-MWNT film modified glass carbon electrode (GCE). Graphene oxide (GO) sheets can serve as surfactants to stabilize the dispersion of pristine MWNTs in aqueous solution, rendering a fine coverage of ERGO-MWNT film on GCE during the fabrication process. MWNTs perform as conducting bridges between ERGO sheets to enhance the electron transfer rate in the substrate. By combining the advantages of ERGO and MWNTs, together with electrocatalytic effect of Ni(OH)2 nanoparticles, the well-designed nanocomposites exhibit excellent sensing behavior towards glucose and hydrogen peroxide (H2O2). The linear detection ranges for glucose and H2O2 are 10-1500 µM and 10 µM-9050 µM while the detection limits are 2.7 µM and 4.0 µM, respectively. Furthermore, a very high sensitivity is achieved with 2042 µAm M(-1) cm(-2) estimated for glucose and 711 µAm M(-1) cm(-2) for H2O2. These results suggest that Ni(OH)2/ERGO-MWNT nanocomposites thus easily prepared through a green electrochemical method are promising electrode materials for biosensing. Additionally, good recoveries of analytes in real samples like urine and milk confirm the reliability of the prepared sensor in practical applications.