Iodine-doped reduced graphene oxide and titanium dioxide nanocomposite as effective amperometric glucose biosensor

Abstract

The current study fabricated a non-enzymatic glucose sensor based on iodine-doped reduced graphene oxide with titanium dioxide (I-rGO@TiO2) nanocomposite. Initially, the sol-gel and thermal reduction methods synthesized titanium dioxide (TiO2) nanoparticles and reduced graphene oxide (rGO). Then, the hydrothermal technique was utilized to synthesize a composite of I-rGO@TiO2 by combining I-rGO and TiO2 in a 1:4 ratio. The XRD spectrum and TEM images revealed that in the I-rGO@TiO2 nanocomposite, nanocrystalline anatase titanium is randomly distributed on the I-rGO sheets. Fourier transforms the infrared spectrum of nanocomposite shows the presence of titanium and oxygen bond characteristics peak between 400 and 850 cm−1. Iodine molecules peak at 100 cm−1 were obtained in Raman spectra. The AC conductivity and dielectric properties of the nanocomposite were analyzed. For the sensor fabrication, the indium tin oxide electrode surface is modified by I-rGO@TiO2, and the electrochemical performance was examined. At room temperature, the sensor demonstrated a wider linear detection range (0.5−10 mM). The lower detection limit of the sensor was 0.23 μM (S/N = 3), and the sensitivity was 221.69 μA mM−1 cm−2. The I-rGO@TiO2 nanocomposite shows a positive temperature coefficient via the thermal activation of charge carriers and a conductivity of 3.82 × 10−5 Ω−1m−1 at 200 °C. Additionally, the antibacterial properties was evaluated, and dose-dependent properties were observed towards E. coli and Bacillus subtilis bacterium.