Au@Ag core-shell nanoparticles (NPs) were synthesized and coupled with copper ion (Cu(2+)) for the colorimetric sensing of iodide ion (I(-)). This assay relies on the fact that the absorption spectra and the color of metallic core-shell NPs are sensitive to their chemical ingredient and dimensional core-to-shell ratio. When I(-) was added to the Au@Ag core-shell NPs-Cu(2+) system/solution, Cu(2+) can oxidize I(-) into iodine (I2), which can further oxidize silver shells to form silver iodide (AgI). The generated Au@AgI core-shell NPs led to color changes from yellow to purple, which was utilized for the colorimetric sensing of I(-). The assay only took 10 min with a lowest detectable concentration of 0.5 μM, and it exhibited excellent selectivity for I(-) over other common anions tested. Furthermore, Au@Ag core-shell NPs-Cu(2+) was embedded into agarose gels as inexpensive and portable "test strips", which were successfully used for the semi-quantitation of I(-) in dried kelps.
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http://dx.doi.org/10.1016/j.aca.2015.06.043 | DOI Listing |
Food Chem
January 2025
China Light Industry Key Laboratory of Food Intelligent Detection & Processing, School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China; International Joint Research Laboratory of Intelligent Agriculture and Agri-products Processing, Jiangsu University, Zhenjiang 212013, China. Electronic address:
Flexible surface-enhanced Raman scattering (SERS) sensors offer a promising solution for the rapid in situ monitoring of food safety. The sensor's capability to furnish quantitative detection and retain recyclability is crucial in practical applications. This study proposes a self-cleaning flexible SERS sensor, augmented with an intelligent algorithm designed for expeditious in situ and non-destructive thiram detection on apples.
View Article and Find Full Text PDFBiosensors (Basel)
December 2024
A.N. Bach Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, Leninsky Prospect 33, 119071 Moscow, Russia.
Gatifloxacin (GAT), an antibiotic belonging to the fluoroquinolone (FQ) class, is a toxicant that may contaminate food products. In this study, a method of ultrasensitive immunochromatographic detection of GAT was developed for the first time. An indirect format of the lateral flow immunoassay (LFIA) was performed.
View Article and Find Full Text PDFACS Nano
December 2024
Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Ontario N2L 3G1, Canada.
In contrast to homogeneous enzyme catalysis, nanozymes are nanosized heterogeneous catalysts that perform reactions on a rigid surface. This fundamental difference between enzymes and nanozymes is often overlooked in kinetic studies and practical applications. In this article, using 14 nanozymes of various compositions (core@shell, metal-organic frameworks, metal, and metal oxide nanoparticles), we systematically demonstrate that nontypical features of nanozymes, such as multiple catalytic activities, chemical transformations, and aggregation, need to be considered in nanozyme catalysis.
View Article and Find Full Text PDFNanoscale Adv
January 2025
Department of Electrical and Electronic Engineering, University of Dhaka Dhaka-1000 Bangladesh
Tandem neural networks for inverse design can only make single predictions, which limits the diversity of predicted structures. Here, we use conditional variational autoencoder (cVAE) for the inverse design of core-shell nanoparticles. cVAE is a type of generative neural network that generates multiple valid solutions for the same input condition.
View Article and Find Full Text PDFInorg Chem
December 2024
College of Materials Science and Engineering, Fuzhou University, Fuzhou 350108, PR China.
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