The advantages of screen-printed electrodes and a laser-induced graphene electrode are well integrated into one flexible sweat sensor, showing high sensitivity to uric acid in sweat and excellent mechanical properties.

Cubic Cu ₂ O film with predominant (111) orientation electrodeposited on Cu foam shows high nitrate reduction efficiency and selectivity for nitrogen gas.

The mechanism and application of localized surface plasmon resonance induced photocatalytic reactions remain an issue of interest. In this work, we used Au@Ag core–shell nanorods as a platform for plasmon-driven photocatalysis, which was in situ investigated by surface-enhanced Raman scattering (SERS) spectroscopy. The para-aminothiophenol (PATP) and para-nitrothiophenol (PNTP) adsorbed on the nanorods were irradiated with different excitation wavelengths (633 nm, 785 nm) and transformed into 4,4′-dimercaptoazobenzene (DMAB) as evidenced by the emerging Raman peaks at 1142 cm⁻¹, 1390 cm⁻¹, 1440 cm⁻¹, and 1477 cm⁻¹, corresponding to hot carrier dominated oxidation of PATP and reduction of PNTP. Preliminary azo-reaction kinetics and in situ SERS measurements were conducted by comparing the relative intensity ratio of SERS peaks at 1440 cm⁻¹ (DMAB stretching of NN) and 1080 cm⁻¹ (C–S stretching of PATP and PNTP). These results indicate that the catalytic efficiency was dominated by the excitation wavelength as well as the resonance condition between the plasmon band of the nanorods and the excitation line. As a proof of concept, the Au@Ag core–shell nanorods were used to catalyze 4-nitrophenol molecules, and 4-hydroxyazobenzene molecules as the product were confirmed by in situ SERS spectra as well theoretical predictions, showing potential in plasmon driven catalysis and degradation of organic molecules.

Three-dimensional surface-enhanced Raman scattering (SERS) substrates usually provide more hot spots in the excitation light beam and higher sensitivity when compared with the two-dimensional counterpart. Here a simple approach is presented for the fabrication of arrays of Ag-nanoparticles decorated TiO₂ nanotubes. Arrays of ZnO nanorods were fabricated in advance by a hydrothermal method. Then TiO₂ nanotube arrays were achieved by immersing the arrays of ZnO nanorods in an aqueous solution of (NH₄)₂TiF₆ for 1.5 h. Vertically aligned TiO₂ nanotube arrays were modified with dense Ag nanoparticles by Ag mirror reaction. High density of Ag nanoparticles decorated on the fabricated TiO₂ nanotubes provide plenty of hotspots for Raman enhancement. In addition, the fabricated array of Ag nanoparticles modified TiO₂ nanotubes can serve as a reusable SERS substrate because of the photocatalytic activity of the TiO₂ nanotubes. The SERS substrate adsorbed with analyte molecules can realize self-cleaning in deionized water after UV irradiation for 2.5 h. The sensitivity of the fabricated SERS substrate was investigated by the detection of organic dye molecules. The detectable concentration limits of rhodamine 6G (R6G), malachite green (MG) and methylene blue (MB) were found to be 10⁻¹² M, 10⁻⁹ M and 10⁻⁸ M, respectively. The enhancement factor (EF) of the three-dimensional SERS substrate was estimated to be as high as ∼1.4×10⁸. Therefore, the prepared Ag nanoparticles modified TiO₂ nanotube arrays have promising potentials to be applied to rapid and trace SERS detection of organic chemicals.