Nanoparticles of Cu2O and TiO2 on Ti3C2T x Heterostructures for Ultrafast Nonenzymatic Glucose Sensing

The exploration of enzyme-mimic nanocomposites to replace commercial enzymes is challenging in the construction of biosensors with high performance. Herein, an ultrafast response nonenzymatic glucose sensor was developed based on a Cu2O-TiO2/Ti3C2Tx nanocomposite, which was prepared via an in situ redox procedure using Ti3C2Tx nanosheets both as a reducing agent and a carrier substrate. Structural characterizations, including X-ray diffraction (XRD) and transmission electron microscopy (TEM), revealed that Cu2O nanoparticles with a size of 10-30 nm are uniformly distributed on the surface of the Ti3C2Tx nanosheets and form close contacts through Ti-O-Cu bonds, resulting in favorable stability of the system. The unique heterostructure of Cu2O-TiO2/Ti3C2Tx can produce abundant active sites and facilitate electron transfer, demonstrating enhanced catalytic activity in the electrooxidation of glucose. Consequently, the electrochemical sensor fabricated by modifying a glassy carbon electrode (GCE) with Cu2O-TiO2/Ti3C2Tx nanocomposites exhibited excellent analytical properties for glucose detection, including a fast response time of 0.1 s, a low detection limit of 0.67 mu M, and a high sensitivity of 267 mu A mM(-1) cm(-2). In addition, the developed method possesses good anti-interference ability and superior stability and thus has been successfully applied for real sample monitoring. This study offers a way to construct Ti3C2Tx-based heterostructures with tunable physiochemical properties and expands their use in the electrochemical field.