Porous biomass carbon and gold nanoparticles modified electrode for myoglobin direct electrochemistry and electrocatalysis

In this paper, a stable porous biomass carbon (BC) and gold (Au) nanoparticles modified carbon ionic liquid electrode (CILE) was prepared for the investigation of direct electrochemistry and electrocatalysis of myoglobin (Mb). BC was synthesized via pyrolysis of Hainan's natural tropical plant Lagerstroemia indica leaves, which was modified on the surface of CILE with Au nanoparticles further electrodeposited on the electrode surface. Then, Mb was cast on the nanocomposite-modified electrode to obtain an electrochemical sensing platform with Nafion film (Nafion/Mb/Au-BC/CILE). Direct electrochemistry of Mb on the modified electrode was investigated with appearance of a pair of enhanced redox peaks, indicating direct electron transfer rate of Mb was accelerated due to the presence of Au-BC nanocomposite. Au-BC nanocomposite exhibited high conductivity, good biocompatibility, and large surface area, which was beneficial for electron transfer of Mb. The Mb modified electrode showed excellent electrocatalytic activity toward the reduction of trichloroacetic acid (TCA) and sodium nitrite (NaNO2), which was further used to establish a new electroanalytical method with satisfied sensitivity in real samples analysis.