Mycological synthesis of Ruthenium oxide quantum dots and their application in the colorimetric detection of H2O2

Abstract

Ruthenium oxide nanoparticles (RuO2 NPs) are one of the most prospective materials at the nanoscale and have comprehensive applications in sensors, microelectronics, energy storage, and more. In an urge to develop novel clean, cost-effective, and efficient synthesis procedures scientists are inclining more towards the biosynthesis of nanoparticles. However, in comparison to other metal oxides, there are no reports on the microbial synthesis of nanocrystalline RuO2, to the best of our knowledge. For the first time, we report on the effective fungal-mediated production of fluorescent Ruthenium oxide quantum dots (RuO2 QDs) by the endophytic fungus Fusarium oxysporum, at room temperature which was previously chemically and physically synthesized at elevated temperatures (more than 1000 °C). Different characterization techniques such as UV–visible (UV–Vis) spectroscopy, Photoluminescence (PL), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Fourier Transformed Infrared Spectroscopy (FTIR) were performed to characterize the RuO2 QDs. We attempted to investigate the colorimetric detection of H2O2 using these mycosynthesized RuO2 QDs at three different ratios. Our results revealed that the RuO2 absorption peak decreases with increasing H2O2 concentration (in the range 10-2M−10−6M) with a limit of detection of 0.39 µM. Further, the proposed assay was also proved to be suitable for the detection of H2O2 spiked-in plasma samples.