Highly selective colorimetric platinum nanoparticle-modified core-shell molybdenum disulfide/silica platform for selectively detecting hydroquinone

The one-step hydrothermal reduction method was used to create platinum nanoparticle (Pt NPs)-modified molybdenum disulfide (MoS2)-silica (SiO2) nanocomposites (Pt-MoS2/SiO2) with excellent peroxidase-like activity. Results of characterization revealed the successful synthesis of Pt-MoS2/SiO2 with the diameter being about 1 mu m. Steady-state kinetic experiments indicated that the catalytic behavior of Pt-MoS2/SiO2 followed the Michaelis-Menten model of enzyme kinetics and had a good affinity with the substrates. The electron spin resonance (ESR) analysis results showed that hydrogen peroxide could be decomposed into hydroxyl radicals (center dot OH) and superoxide radicals (center dot O-2(-)) under the catalysis of Pt-MoS2/SiO2, and followed by oxidizing colorless 3,3',5,5'-tetramethylbenzidine (TMB) into a blue oxidation product (oxTMB). However, hydroquinone (HQ) could prevent TMB from oxidizing, and the amount of fade relied on the amount of HQ. This led to the development of a quick, sensitive, and accurate colorimetric sensing device for HQ, with a linear range of 0.5-9 mu M and a limit of detection (LOD) as low as 0.242 mu M. Furthermore, the satisfactory sensitivity and selectivity of HQ sensing platform in tap water and river water samples endowed it as a potential candidate in real applications.

Automated summary

The one-step hydrothermal reduction method was used to synthesize platinum nanoparticle-modified molybdenum disulfide-silica nanocomposites with excellent peroxidase-like activity. These nanocomposites showed the ability to decompose hydrogen peroxide into hydroxyl radicals and superoxide radicals, and were able to oxidize colorless 3,3',5,5'-tetramethylbenzidine into a blue oxidation product. A colorimetric sensing device for hydroquinone was developed using the nanocomposites, with a linear range of 0.5-9 μM and a low limit of detection. This sensing platform exhibited satisfactory sensitivity and selectivity in tap water and river water samples.