Improved Oxidation of Graphite for Different Oxidation Time and for Different Concentration of Oxidizing Agent for Cellular Sensing

Shivangi Kosta, Prerna Bansal, Niroj Kumar Sahu

In the present work, graphite has been oxidized by a modified oxidation method. Structural and optical properties of as prepared graphite oxide (GO) have been investigated for different oxidation time and for different concentrations of oxidizing agent (KMnO4). GO samples were prepared by varying the oxidation time (18hrs, 14hrs and 6hrs) and graphite: KMnO4 wt% ratios (1:3, 1:6 and 1:9). As-synthesized GO was characterized by XRD, FTIR, Zeta potential and UV-vis spectroscopic techniques. Our XRD results indicated oxidation of graphite through a shift in the position of [002] diffraction peak of graphite from 26º to 9º-10º for GO. We observed maximum d-spacing (0.932nm) for GO sample prepared for 6hrs with 1:6 wt% of graphite: KMnO4. GO sample prepared for 6hrs showed its excellent water dispersibility with zeta potential value of -43.35mV. Present study suggest that GO sample prepared for 6 hr oxidation time with 1:6 wt% of graphite:KMnO4 gives maximum exfoliation of graphite and is rich of all major oxygen functional groups. In comparison to the existing oxidation methods, our modified oxidation method is suitable for large scale preparation of highly oxygen functionalized GO in less oxidation time (6hrs). As-prepared GO was further used for detection of cancer cells through electrochemical approach.