A colorimetric method combining WSe2 nanosheets with peroxidase-like activity and xanthine oxidase (XAO) was developed for xanthine detection. XAO catalyzes xanthine oxidation and thereby induces H2O2 production. WSe2 nanosheets can catalyze the oxidization of 3,3′,5,5′-tetramethylbenzidine (TMB) by H2O2 and produce a blue oxidation product of TMB (oxTMB). Under optimal conditions, the colorimetric method showed a linear response for xanthine detection in a range of 0.01–0.5 mM. The limit of detection was 4.37 μM. The recovery rate from spiked serum samples was 95.5%–115.5%. Therefore, our strategy provides new opportunities for the detection of xanthine and evaluation of health care.
As one of the transition metal dichalcogenide materials, WSe2 in the form of a few layers (nanosheets) have received much attention due to their unique physical, optical and electrical properties. Herein, we demonstrate that WSe2 nanosheets possess intrinsic enzyme mimic activity. Under acidic conditions, they exhibit pronounced peroxidase-like property. The Michaelis–Menten kinetics indicate that the catalytic activity of WSe2 nanosheets is comparable to that of horseradish peroxidase. Based on the color reaction, a platform of WSe2 nanosheets was constructed to detect glucose concentration and it showed high sensitivity and high selectivity, which means that WSe2 nanosheets with peroxidase-like property can be used to develop a highly sensitive and selective colorimetric method for glucose detection. Moreover, due to the electron-transferring and antioxidant properties of WSe2 few layers, the peroxidase-like catalysis is proposed. These findings pave the way for further application of WSe2 nanosheets in nano-biomedicine.
Hong Li,Zhijian Peng,Jingwen Qian,Meng Wang,Chengbiao Wang,Xiuli Fu
Recently, WSe2 as a typical transition metal dichalcogenide compound has attracted extensive attention due to its potential applications in electronic and optoelectronic devices. However, WSe2 alone cannot be directly used as a photocatalyst due to its inferior performance possibly caused by the strong recombination of photogenerated electron–hole pairs. Here a novel C fibers@WSe2 nanoplates core–shell composite (NPCSC) was successfully synthesized via facile, one-step thermal evaporation, in which numerous WSe2 thin nanoplates were in situ, densely and even vertically grown on the surface of the C fibers. Such composite presents highly solar-driven photocatalytic activity and stability for the degradation of various organic aqueous dyes including methylene blue and rhodamine B, and highly harmful gases like toluene, showing the great potential for environmental remediation by degrading toxic industrial chemicals using sunlight. Under simulated sunlight irradiation, comparing with commercially available WSe2 powder, the as-synthesized C fibers@WSe2 NPCSC presents significantly enhanced reaction rate constants by a factor of approximately 15, 9, and 3 for the degradation of aqueous methylene blue, aqueous rhodamine B, and gaseous toluene, respectively, due to the effective separation of photogenerated electron–hole pairs promoted by the rapid transfer of photogenerated electrons through C fibers. Moreover, this one-step thermal evaporation is an easy-handling, environmentally friendly, and low-cost synthesis method, which is suitable for large-scale production.
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