Techniques for rapid screening of uranium in environmental samples are needed, and this study entails the development of surface-enhanced Raman scattering (SERS) for analyzing uranium in aqueous media with improved sensitivity and reproducibility. A new SERS substrate based on (aminomethyl)phosphonic acid (APA)-modified gold nanoparticles was found to give greater than three orders of magnitude SERS enhancement compared with unmodified bare gold nanoparticles. Intensities of uranyl band at about 830 cm(-1) were proportional to the concentrations of uranium in solution, especially at relatively low concentrations (<10(-5) M). A detection limit of approximately 8x10(-7) M was achieved with a good reproducibility since the measurement was performed directly in dispersed aqueous suspension. Without pretreatment, the technique was successfully employed for detecting uranium in a highly contaminated groundwater with a low pH, high dissolved salts (e.g., nitrate, sulfate, calcium and aluminum) and total organic carbon.
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http://dx.doi.org/10.1016/j.aca.2007.10.024 | DOI Listing |
RSC Adv
January 2025
The Center for Chemical Biology, School of Fundamental Science and Technology, Graduate School of Science and Technology, Keio University 3-14-1 Hiyoshi, Kohoku-ku Yokohama 223-8522 Japan +81-45-566-1580 +81-45-566-1839.
We prepared a cellulose nanofiber (CNF)-based porous membrane with three dimensional cellular structures. CNF was concentrated a surfactant-induced assembly by mixing CNF with a cationic surfactant, domiphen bromide (DB). Furthermore, they were accumulated by centrifugation to obtain a CNF-DB sol.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Department of Chemical Engineering, Ataturk University, 25240 Erzurum, Turkey.
The combination of plasmonic metals and MXene, as a new and interesting member of the 2D material class, may provide unique advantages in terms of low cost, versatility, flexibility, and improved activity as an ideal surface-enhanced Raman spectroscopy (SERS) platform. Despite the recent progress, the present studies on the utilization of plasmonic metal/MXene-based SERS systems are quite limited and thereby benefits of the extraordinary properties of this combination cannot be realized. In this study, for the first time, we propose layer-by-layer (LbL) thin films of TiC MXene and gold nanoparticles (AuNPs) as a robust SERS platform (TiC/AuNPs).
View Article and Find Full Text PDFSoft Matter
January 2025
Faculty of Chemistry, Ho Chi Minh City University of Science, Vietnam National University, Ho Chi Minh City, 227 Nguyen Van Cu Street, Ward 4, District 5, Ho Chi Minh City 70000, Vietnam.
Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive analytical technique with excellent molecular specificity. However, separate pristine nanoparticles produce relatively weak Raman signals. It is necessary to focus on increasing the "hot-spot" density generated at the nanogaps between the adjacent nanoparticles (second-generation SERS hotspot), thus significantly boosting the Raman signal by creating an electromagnetic field.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
Department of Chemistry, Cape Breton University, Sydney, Nova Scotia B1P 6L2, Canada.
Nitrite is an important chemical intermediate in the nitrogen cycle and is ubiquitously present in environmental and biological systems as a metabolite or additive in the agricultural and food industries. However, nitrite can also be toxic in excessive concentrations. As such, the development of quick, sensitive, and portable assays for its measurement is desirable.
View Article and Find Full Text PDFAnal Chem
January 2025
State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, PR China.
An entropy-driven catalysis (EDC) strategy is appealing for amplified bioimaging of microRNAs in living cells; yet, complex operation procedures, lacking of cell selectivity, and insufficient accuracy hamper its further applications. Here, we introduce an ingenious all-in-one entropy-driven DNA nanomachine (termed as AIO-EDN), which can be triggered by endogenous apurinic/apyrimidinic endonuclease 1 (APE1) to achieve tumor cell-selective dual-mode imaging of microRNA. Compared with the traditional EDC strategy, the integrated design of AIO-EDN achieves autocatalytic signal amplification without extra fuel strands.
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