RESUMO
With the widespread use of uranium in the nuclear industry, achieving rapid and sensitive detection of uranium contaminants is critical for reducing environmental pollution. Surface-enhanced Raman scattering (SERS), with its high sensitivity and unique fingerprint properties, has been used for the analysis of uranyl. However, the weak affinity of Au for uranyl remains a challenge in the development of spherical Au-based SERS substrates. The metal-organic framework (MOF) material ZIF-8 exhibits excellent adsorption capacity for uranyl and could overcome this limitation. In this study, ZIF-8 porous structures were modified on a magnetic SERS substrate, Fe3O4@SiO2@Au (FA), for the rapid and sensitive detection and analysis of the uranyl species. Uranyl was adsorbed by ZIF-8, allowing ready access to the hot spots in the interstices of Au nanoparticles (AuNPs). Symmetrically stretched vibrating bonds of OâUâO were detected at 829 cm-1 as the characteristic peak of uranyl by surface plasmon resonance between the AuNPs. The ZIF-8 coating had minimal influence on target detection as the detection limit for 4-MPY was only half an order of magnitude lower than before modification. The enhancement factor for uranyl reached 106. The substrate showed excellent sensing performance in a neutral or alkaline environment. It was used to detect uranyl in tap water and river water; rapid separation of the species from the water samples was achieved using an external magnet to extract radioactive waste. The proposed substrate offers a route for monitoring and detecting uranyl contamination and an approach for achieving rapid on-site detection, providing a promising application for environmental contaminant detection.
RESUMO
A novel breakthrough has been achieved in gas detection through the innovative application of surface-enhanced Raman scattering (SERS) to hydrogen (H2) detection for the first time. This study capitalizes on the unique SERS effects of gold nanoparticles coupled with the redox interaction between hydrogen and crystal violet, allowing for the development of a magnetic SERS probe that demonstrated enhanced sensitivity and specificity. This new probe can detect hydrogen concentrations as low as 1% by volume in gaseous environments, offering a substantial improvement over the detection limits of traditional hydrogen alarms. Further, this report comprehensively detailed the synthesis of the FA-CV materials, instrumental analysis, and an in-depth evaluation of the SERS performance of the FA-CV substrate, underlining the outstanding sensitivity, stability, and recyclability of the probe. The introduction of SERS in this novel capacity not only contributes a valuable approach to gas sensing technologies, but also suggests promising avenues for the application of SERS in environmental monitoring and energy security. This illustrates the adaptability and potential impact of this powerful technique.