Peptide Nanosheet-Inspired Biomimetic Synthesis of CuS Nanoparticles on Ti3C2 Nanosheets for Electrochemical Biosensing of Hydrogen Peroxide

Hydrogen peroxide (H₂O₂) is one of the intermediates or final products of biological metabolism and participates in many important biological processes of life activities. The detection of H₂O₂ is of great significance in clinical disease monitoring, environmental protection, and bioanalysis. In this study, Ti₃C₂-based nanohybrids are prepared by the biological modification and self-assembled peptide nanosheets (PNSs)-based biomimetic synthesis of copper sulfide nanoparticles (CuS NPs), which show potential application in the fabrication of low-cost and high-performance electrochemical H₂O₂ biosensors. The synthesized CuS-PNSs/Ti₃C₂ nanohybrids exhibit excellent electrochemical performance towards H₂O₂, in which CuS NPs can catalyze the decomposition of H₂O₂ and realize the transformation from a chemical signal to an electrical signal to achieve the purpose of H₂O₂ detection. The prepared CuS-PNSs/Ti₃C₂-based electrochemical biosensor platform exhibits a wide detection range (5 μM-15 mM) and a low detection limit (0.226 μM). In addition, it reveals good selectivity and stability and can realize the monitoring of H₂O₂ in a complex environment. The successful biomimetic synthesis of CuS-PNSs/Ti₃C₂ hybrid nanomaterials provides a green and friendly strategy for the design and synthesis of functional nanomaterials and also provides a new inspiration for the construction of highly effective electrochemical biosensors for practical detection of H₂O₂ in various environments.

A multifunctional Ni-doped iron pyrite/reduced graphene oxide composite as an efficient counter electrode for DSSCs and as a non-enzymatic hydrogen peroxide electrochemical sensor

Nickel-doped FeS₂/rGO composites were synthesized as multifunctional materials via a facile hydrothermal method. The synthesized materials were characterized with XRD, FESEM, XPS, and TEM-SAED for structural, morphological and chemical studies. To study their electrochemical properties, all the synthesized composites were subjected to cyclic voltammetry tests. The optimum composite revealed high catalytic activity with high peak current density, limiting current, and efficiency of 7.60% for DSSC, which surpassed that of a platinum-based counter electrode (6.69%). The efficiency of the DSSC was significantly supported by interfacial studies and electron lifetime studies, and it exhibited lower charge transfer resistance and higher electron lifetime, respectively. Moreover, the fabricated DSSCs with high efficiency were subjected to transient photo-response studies and showed a stable current response with multiple photo-ON and OFF cycles for a period of 600 s. To broaden the application of the synthesized material, it was used as an electrochemical sensor for the efficient sensing of hydrogen peroxide (H₂O₂). The sensing electrode was modified with the optimum Ni-doped FeS₂/rGO composite, and voltammetric detection was carried out in the hydrogen peroxide concentration range of 4-100 μM. Thus, the synthesized material can be applied in DSSCs and as an electrochemical H₂O₂ sensor.

Facile synthesis of core-shell CuS-Cu2S based nanocomposite for the high-performance glucose detection

Glucose detection is of great importance for the medical diagnosis, food biotechnology and pharmaceutical analysis. In this study, we synthesized a core-shell CuS-Cu₂S decorated carbon nanotube-graphene nanocomposite via a facile hydrothermal method. It exhibits great sensing performance towards glucose with wide linear range ranging from 0.001 to 2 mM, ultra-sensitivity of 1923 μA·cm^-2·mM^-1 and 0.33 μM detection limit in alkaline solutions. The excellent electrocatalytic activity originates from the synergistic effect between heterogeneous copper sulfides structures and carbon nanomaterials. Besides, the fabricate sensor also has great durability, selectivity and great potential for practical applications.