Nonenzymatic H 2 O 2 Electrochemical Sensor Based on SnO 2 ‐NPs Coated Polyethylenimine Functionalized Graphene

This paper demonstrated using polyethylenimine (PEI)‐functionalized graphene (Gr) incorporating tin oxide (SnO 2 ) hybrid nanocomposite as a platform for nonenzymatic H 2 O 2 electrochemical sensor. The results of UV‐vis spectroscopy and X‐ray diffraction (XRD) confirmed the simultaneous formation of tin oxide (SnO 2 ) nanocomposite and reduction of graphene oxide (GO). Transmission electron microscopy (TEM) images showed a uniform distribution of nanometer‐sized tin oxide nanoparticles on the grapheme sheets, which could be achieved using stannous chloride (SnCl 2 ) complex instead of tin oxide as precursor. The electrochemical measurements, including cyclic voltammetry (CV) and amperometric performance (I‐t), showed that the PEI‐functionalized Gr supported SnO 2 (SnO 2 ‐PEI‐Gr) exhibited an excellent electrocatalytic activity toward the H 2 O 2 . The corresponding calibration curve of the current response showed a linear detection range of 9×10 −6 ∼1.64×10 −3  mol L −1 , while the limit of detection was estimated to be 1×10 −6  mol L −1 . Electrochemical studies indicated that SnO 2 and functionalized Gr worked synergistically for the detection of H 2 O 2 .