A colorimetric sensing platform for the determination of H(2)O(2) using 2D–1D MoS(2)-CNT nanozymes

A novel colorimetric platform based on nano-composites of two-dimensional (2D) molybdenum disulfide nanosheets (MoS(2) NSs) and one-dimensional (1D) carbon nanotubes (CNTs), called 2D–1D MoS(2)-CNT nanozyme, was fabricated for the selective and sensitive determination of hydrogen peroxide (H(2)O(2)) in soda water. The MoS(2)-CNT nanozyme was synthesized through a one-step solvothermal reduction method. The introduced CNTs could effectively prevent the stacking of MoS(2) nanosheets (NSs) and not only expanded the interlayer distance of MoS(2) NSs from 0.620 nm to 0.710 nm but also improved their specific surface. Under acidic conditions, the as-prepared 2D–1D MoS(2)-CNT nanozymes could oxidize the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) to blue-oxidized TMB (oxTMB) in the presence of H(2)O(2), resulting in enhanced peroxidase-like (POD-like) activity. The kinetic study showed that MoS(2)-CNT nanozyme had stronger catalytic activity than natural horseradish peroxidase (HRP). The linear range for H(2)O(2) colorimetric determination was 5.00–500 μmol L(−1) with a limit of detection (LOD) of 1.40 μmol L(−1). Furthermore, the established determination method was applied to actual samples and the recoveries of H(2)O(2) spiked in soda water were in the range of 92.3–107%, showing feasibility for the analysis of food.