Facile Hydrothermal Synthesis of in2O3 Nanoboxes for Electrochemical Sensing of Paraben

Novel indium oxide (In₂O₃) nanoboxes have been prepared by template-less and surfactant-free hydrothermal synthesis. Synthesized In₂O₃ nanoboxes were characterized by X-ray diffraction (XRD) and field emission scanning electronic microscopy (FESEM). FESEM micrographs revealed highly uniform nanoboxes with smooth surfaces and XRD analysis confirmed that these In₂O₃ nanoboxes grown with a cubic crystal structure. The synthesized In₂O₃ nanoboxes were successfully immobilized on the surface of glassy carbon electrode for the detection of Parabens (butylparaben). Owing to the unique structure and intriguing properties of these In₂O₃ nanoboxes, the film electrode has shown an obvious electrocatalytic activity for the detection of butylparaben (BP), since it facilitates the electron transfer and significantly enhances the oxidation peak current and lowering of the detection limit of BP. The calibration plot of concentration versus peak current was found to be linear over the range of 0.14 µM to 2.4 µM. The detection limit (LOD) was estimated as 3s/m and was found to be 0.08 µM.  This sensor showed high sensitivity compared with other electrochemical sensors reported so far for the detection of BP.