Surface Environment and Energy Density Effects on the Detection and Disinfection of Microorganisms Using a Portable Instrument

The disinfectant effects of portable ultraviolet light devices and their application to dentures

Interest in ultraviolet (UV) light devices for disinfection has increased due to pandemic concerns, but their efficacy in denture disinfection is underexplored. This study evaluated seven-enclosed type portable UV irradiation devices (devices A-G). Among these, devices A, B, and C used bulb light sources, while devices D, E, F, and G utilized LED (light-emitting diode) light sources. All devices were assessed in agar plate assay, and Candida albicans and Staphylococcus aureus spread on agar plates and irradiated under two conditions: inoculated surface facing upward and downward. Colony counts were recorded. Devices A and D were tested on C. albicans-contaminated dentures immersed in C. albicans medium, with samples collected before and after irradiation on the mucosal surfaces of the dentures. Device A was tested on denture-wearing patients in a clinical study, with samples collected from mucosal surfaces before and after irradiation to assess microbial CFUs (colony forming units). Devices A, C, and D significantly reduced C. albicans and S. aureus on plates with the inoculated surface facing upward, while device F showed a slight reduction when the inoculated surfaces were facing downward. Devices A and D eliminated C. albicans on contaminated dentures in vitro. Device A reduced all microorganism CFUs on denture surfaces in clinical studies. This study demonstrates that some portable UV light devices effectively reduce microbial contamination on denture surfaces, suggesting their potential as valuable tools for improving denture hygiene in the future.

Recent advances and new insights on the construction of photocatalytic systems for environmental disinfection

Photocatalysis, as a sustainable and environmentally friendly green technology, has garnered widespread recognition and application across various fields. Especially its potential in environmental disinfection has been highly valued by researchers. This study commences with foundational research on photocatalytic disinfection technology and provides a comprehensive overview of its current developmental status. It elucidates the complexity of the interface reaction mechanism between photocatalysts and microorganisms, providing valuable insights from the perspectives of materials and microorganisms. This study reviews the latest design and modification strategies (Build heterojunction, defect engineering, and heteroatom doping) for photocatalysts in environmental disinfection. Moreover, this study investigates the research focuses and links in constructing photocatalytic disinfection systems, including photochemical reactors, light sources, and material immobilization technologies. It studies the complex challenges and influencing factors generated by different environmental media during the disinfection process. Simultaneously, a comprehensive review extensively covers the research status of photocatalytic disinfection concerning bacteria, fungi, and viruses. It reveals the observable efficiency differences caused by the microstructure of microorganisms during photocatalytic reactions. Based on these influencing factors, the economy and effectiveness of photocatalytic disinfection systems are analyzed and discussed. Finally, this study summarizes the current application status of photocatalytic disinfection products. The challenges faced by the synthesis and application of future photocatalysts are proposed, and the future development in this field is discussed. The potential for research and innovation has been further emphasized, with the core on improving efficiency, reducing costs, and strengthening the practical application of photocatalysis in environmental disinfection.