In this study, a kind of graphene oxide-cuprous oxide (GO-Cu₂O) nanocomposites was fabricated with different morphologies to serve as a photocatalytic material for the degradation of organic/inorganic dyes under visible light and the bactericidal effect against pathogenic bacteria. The GO-Cu₂O was prepared with solid cube and hollow dodecahedra morphologies through in-situ synthesis, and characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Raman, Ultraviolet and visible spectrophotometry (UV/vis), and Fourier transform infrared spectroscopy. In comparison with cubic GO-Cu₂O, the absorption and degradation efficiency of the GO-Cu₂O dodecahedra (GCD) composite in Methyl orange (MO), Rhodamine B (RhB), and phenol was higher owning to the more active sites for the simultaneous dye and light absorption of hollow structure. The antibacterial effect of the GO-Cu2O dodecahedra was examined by the flat colony counting method with an excellent bactericidal effect against pathogenic bacteria. The possible mechanism for the preparation of GCD possessing the enhancement of the visible-light photocatalytic and antibacterial efficiencies were also investigated.

Schematic representation of the synthetic strategy for TiO₂/Ag₃PO₄/GR composites.

As rare-earth coordination polymers (CPs) have appreciable antimicrobial properties, ternary lanthanum CPs have been widely synthesized and investigated in recent years. Here, we report convenient, solvent-free reactions between the lanthanum salt and two ligands at mild temperatures that form ternary lanthanum nanoscale CPs with 10-gram-scale. The structural features and morphologies were characterized using a scanning electron microscope (SEM), Fourier transform infrared spectrometer (FT-IR), ultraviolet-visible (UV–Vis), X-ray diffractometer (XRD), X-ray Photoelectron Spectroscopy (XPS), Brunauer–Emmett–Teller (BET), elemental analysis, inductively coupled plasma mass spectrometry (ICP-MS), electrospray ionization mass spectrometry (ESI-MS), nuclear magnetic resonance (NMR), dynamic light scattering (DLS) and analyzer, and thermogravimetric and differential thermal analyzer (TG-DTA). Furthermore, the in vitro antibacterial activities of these ternary hybrids were studied using the zone of inhibition (ZOI) method, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and transmission electron microscope (TEM) and were found to have excellent antibacterial properties. The in vitro antitumor activities were performed in determining the absorbance values by CCK-8 (Cell Counting Kit-8) assay. This facile synthetic method would potentially enable the mass production of ternary lanthanum CPs at room temperature, which can be promising candidates as antibacterial compounds and antitumor agents.

Introducing oxygen-vacancy into the surface of the non-enzymatic sensor is supposed to be an effective way to improve inherently low catalytic activity and specificity of non-enzymatic sensors. In this work, CuO/C was synthesized at different temperatures using metal-organic frameworks as sacrificial templates to receive additional content of oxygen-vacancy. The product with the highest oxygen vacancy was found at 400 °C (named CuO/C-400 °C), which increased catalytically active sites and enhanced the charge-transfer efficiency. The sensing performance was afterward explored by amperometry under an optimal applied potential at 0.5 V (vs. SCE), presenting a broad detection range from 5.0 µM to 25.325 mM (R² = 0.9998) with a sensitivity of 244.71 µA mM^− 1 cm^− 2, and a detection limit of 1 µM. Furthermore, the reliability and selectivity of CuO/C-400 °C sensors were extensively explored in the presence of artificial serum/saliva samples with gradient glucose concentrations. The human blood samples were also detected with high recoveries compared with the clinical Hexokinase method. Hence, the prepared CuO/C-400 °C sensor with a broad detection range and high selectivity can be applied for the diabetes diagnosis ex vivo without further dilution for real-time analysis in practical applications.