We have produced an innovative, theranostic hybrid nanocomposite of graphene oxide and iron oxide (GO–Fe₃O₄) for radio-frequency hyperthermia therapy. A new electrochemical synthesis route for the GO–Fe₃O₄ nanocomposite is employed. Superparamagnetic nanoparticles used for magnetic hyperthermia for biomedical application face longstanding obstacles, including the large number of nanoparticles required to achieve the desired therapeutic temperature, poor colloidal stability in aqueous suspension or physiological media, poor biocompatibility and, most importantly, low specific absorption rate (SAR). To limit the dosage of nanoparticles for therapeutic use, efforts are being made to increase the heating efficiency of nanoparticles. We have introduced an alternative way to increase the SAR value by improving the colloidal stability of magnetic nanoparticles. It is necessary to immobilize these nanoparticles on a support to prevent their agglomeration and precipitation in aqueous suspension. To address these issues, we report a reproducible electrochemical synthesis route for the GO–Fe₃O₄ nanocomposite. Our nanocomposite demonstrated good colloidal stability and low cytotoxicity in vitro. Due to its good colloidal stability, the nanocomposite had a high SAR of 543 W g⁻¹ and corresponding intrinsic loss power of 5.98 nH m² kg⁻¹, which is 46% better than the best commercial equivalents. In vitro cytotoxicity studies demonstrated almost 70% cell viability at 200 μg mL⁻¹ GO–Fe₃O₄ nanocomposite, a comparable concentration for clinical use according to FDA standards. We also showed the therapeutic potential of the nanocomposite using magnetic hyperthermia. We observed cancer cell (A549 human lung epithelial adenocarcinoma) ablation at 41, 42 and 43 °C for 30, 45, and 60 min. A maximum cancer cell death rate of 80.5% was observed at 43 °C for 60 min under alternating magnetic field exposure. Thus, the nanocomposites could be used in the efficient treatment of cancer.

Chitosan-coated Fe₃O₄nanoparticles induced rapid tumor ablation using magnetic hyperthermia, possibly mediated by caspase-3 dependent apoptosis andIL-6signaling, and showed gradual clearance from the excretory, hepatic and circulatory system in rats.

Graphene based 2D materials with a surfeit of active sites and advantageously high surface to volume ratio are effectively linked to well established nanostructured semiconducting metal oxides for development of nanocomposites with enhanced gas sensing properties. Graphene Oxide (GO), a sister material of graphene, is therefore a natural choice for development of room temperature operated gas sensors. In the current investigation hydrothermally grown GO and ZnO nanorods composite (GO–ZnO–NR) is utilised for room temperature gas sensing of H₂ and SO₂ gases. Room temperature detection of H₂ and SO₂ at sub-100 ppm levels with linear variation in response for different concentrations is demonstrated. Morphological and structural analyses are conducted using Scanning electron microscopy, Raman spectroscopy and X-ray diffraction. GO-ZnO-NR composite sensor is seen to exhibit robust sensing response of 5.82 and 5.45 for 100 ppm each of H₂ and SO₂ gases respectively at room temperature. Further, the delayed response and recovery times exhibited by the sensor for SO₂ gas are recognized to be due to formation of strongly adhering SO₃ species.

Aim: To explore the optimum temperature for cancer cell death using magnetic hyperthermia (MH), which in turn will affect the mode of cell death. Method: The focus of this study is to improve upon ...