CuxO nanoparticles loaded LTA zeolite as non-enzymatic and noble-metal-free sensing platform for accurate and fast glucose detection

For glucose sensors, improved sensitivity, accuracy, stability and convenience have always been desired. A novel sensing platform combining CuxO (x = 1, 2) nanoparticles and LTA-structured zeolite well fulfills these requirements and achieves breakthrough sensing concentration (6.0 × 10−15 M). In hydrothermal conditions, highly dispersed CuxO nanoparticles are formed and restrined in the nano-opening windows of the zeolite surface pores, ultimately yielding CuxO LTA. These in situ-synthesized CuxO NPs have high catalytic activity, while the zeolite provides a stable and rigid framework. This sensor has good selectivity and sensitivity (1.45 μA μM−1 cm−2) for the determination of glucose under physiological conditions (pH = 7.4) using the DPV method with a limit of detection (LOD) as low as 6.0 × 10−15 M. The amperometry method exhibited a fast response time of only 0.1 s under strong alkaline conditions (1.0 M NaOH) and achieved a sensitivity of 6.94 μA μM−1 cm−2 and LOD of 2.0 × 10−9 M. This advanced hybrid sensor system not only provides a wide range of application environments, but also has important implications for the development of low-cost, stable, fast, and efficient non-enzymatic glucose sensors for noble metals. The theoretical support of density-functional theory (DFT) affirms the interaction between zeolite fine structure and glucose molecules.