A high-performance enzyme-free glucose sensor based on CuS nanoplates with exposed (110) planes

Abstract

The exposing of active crystal facets plays a crucial role in tailoring the electrochemical properties of nanocrystals. Herein, CuS hexagonal nanoplates with exposed (110) planes (CuS-P) were synthesized via a microwave-assisted homogeneous precipitation route. Structural characterization, including XRD and TEM, revealed that the CuS nanoplates were (110) facet exposed and that their morphologies could be mediated through polyvinylpyrrolidone coordination. These CuS-P nanoplates possessed excellent electrochemical properties and demonstrated good catalytic activity in the electro-oxidation of glucose. The (110) crystal facets on CuS improve the adsorption and activation of glucose, accelerating the electrochemical reaction. A novel nonenzymatic glucose sensor was fabricated by modifying a glassy carbon electrode (GCE) with CuS-P nanoplates. The sensor exhibited an ultrafast response rate (< 0.1 s), a low detection limit of 0.38 µM and a wide linear range of 10 µM ∼ 15.0 mM. In addition, the developed method showed good anti-interference capability and outstanding stability. When the nonenzymatic sensor was adopted to detect glucose in human serum, the recoveries ranged from 98.8 % to 101.4 %, and the relative standard deviation (RSD) was less than 2.0 %, indicating its practical use. This study offers an in-depth understanding of the crystal facet effect in the construction of high-performance electrochemical sensors.