PHOTOLUMINESCENCE SPECTROSCOPIC STUDIES OF MN2O3/CO3O4-GLUCOSE/LACTOSE COMPLEXES

As nanoparticles serve as mediators in the electron transfer between biomolecules and a biosensor’s electrode surface, this study is dedicated to investigating Mn2O3 and Co3O4 nanoparticles and their photoluminescence effect that play a critical role in sensing glucose and lactose. The chemical coprecipitation method was adopted for preparing the nanoparticles that were characterized by X-Ray Diffraction, Transmission Electron Microscope, Fourier Transform Infrared spectroscopy, Energy Dispersive X-ray, UV-vis spectroscopy, and Vibrating Sample Magnetometry. It was found that the obtained Mn2O3 and Co3O4 nanoparticles were successfully prepared, with a crystallite size of 65.91 and 58.00 nm, respectively. The high specific surface area of 1.2808 ́104 and 0.5711 ́104 m2/kg was noticed for the Mn2O3 and Co3O4 nanoparticles that exhibited highly agglomerated cubic and spherical nanoparticles, respectively. The energy gap, Urbach energy, and steepness parameter were obtained (1.72 eV, 1.049 eV and 24.644 ́10-3 for Mn2O3 and 1.285/2.165 eV, 2.893 eV and 8.936 ́10-3 for Co3O4) and discussed. Antiferromagnetism and weak ferromagnetism were detected for Mn2O3 and Co3O4 nanoparticles, respectively, with higher saturation magnetization for Mn2O3 (2.435 emu/g). Moreover, the non-enzymatic glucose and lactose biosensor’s compatibility was evaluated utilizing photoluminescence changes. The glucose/lactose interactions with Mn2O3 /Co3O4 nanoparticles were measured by photoluminescence spectroscopy, at room temperature, in a phosphate buffer medium. The addition of Mn2O3 nanoparticles to glucose and lactose demonstrated higher shifts in the photoluminescence intensities with larger binding constants (1625 and 1840 M-1) and more negative Gibbs energy (-17.608 and -18.753 kJ.mol-1). These characteristics promote the investigation of Mn2O3 nanoparticles in glucose and lactose biosensors.