A simple preparation of N-doped reduced graphene oxide as an electrode material for the detection of hydrogen peroxide and glucose

This paper presents a method of simple and facile preparation of N-doped reduced graphene oxide (N-rGO), which can be applied as a metal-free electroactive electrode material for the detection of hydrogen peroxide and glucose. Two different N-rGO samples (N-rGO_850 and N-rGO_950) were obtained by gaseous NH3-assisted thermal modification of reduced graphene oxide (rGO) at temperatures of 850 degrees C and 950 degrees C for 4 and 8 h, respectively. The structural properties of the samples obtained were characterized by Raman spectroscopy, XPS, and N-2 adsorption-desorption techniques. Taken together, these analyses demonstrate that, compared to the N-rGO_850 sample, N-rGO_950 possesses a considerably higher amount of quaternary nitrogen species, higher surface area, and a greater amount of structural imperfections, which contribute to its excellent electrochemical activity in the detection of H2O2 and glucose. The sensor based on N-rGO_950 displays a fast response time (similar to 6 s) to sensitive detection of H2O2, a wide linear range (0.1 - 10.7 mM), a sufficiently low limit of detection (LOD) of 26.0 mu M, and a superior sensitivity (305 mu A mM(-1) cm(-2)). When the same sensor platform used in glucose detection after GOx immobilization results in LOD of 24.7 mu M with a linear range of 0.01 - 3.38 mM and a sensitivity of 60.2 mu A mM(-1) cm(-2). Moreover, the proposed (bio)sensor demonstrates satisfactory selectivity, reproducibility, repeatability, and stability.

Automated summary

This paper presents a simple and facile method for preparing N-doped reduced graphene oxide (N-rGO) as an electroactive electrode material for the detection of hydrogen peroxide and glucose. Two different N-rGO samples were obtained by thermal modification of reduced graphene oxide at different temperatures. The N-rGO_950 sample showed higher electrochemical activity and sensitivity compared to the N-rGO_850 sample due to its higher amount of nitrogen species and surface area. The sensor based on N-rGO_950 exhibited fast response time, wide linear range, low limit of detection, and superior sensitivity for the detection of H2O2 and glucose.