Copper, silver, gold and other heavy metals are potentially toxic to cells. Copper is also essential and cellular levels must be carefully controlled. In contrast, there is no known biological role for silver or gold and they have not been recognized as metals that are under homeostatic control. Using a luminescent biosensor based of the Vibrio fischeri lux gene cluster under the control of the Escherichia coli copA promoter/CueR metal-responsive regulator, we could show that in E. coli, cytoplasmic copper and silver, but not gold, are regulated by the CopA ATPase, the major copper efflux pump.
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http://dx.doi.org/10.1016/s0014-5793(03)00640-9 | DOI Listing |
Int J Biol Macromol
January 2025
Centro de Investigaciones en Ciencias Microbiológicas, Instituto de Ciencias, Benemérita Universidad Autónoma de Puebla, Av. San Claudio y Av. 24 Sur, Col. San Manuel Ciudad Universitaria, Puebla C.P. 72570, Mexico. Electronic address:
This work presents the effect of Polyhydroxybutyrate nanospheres (PHB-NSs) on the bacterial activity of plasmonic nanoparticles (NPs). The PHB-NSs were used as a substrate for the metal-NPs. Silver and gold NPs in colloidal solution were synthesized by chemical reduction, while PHB-NSs were synthesized by a physical method.
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January 2025
MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou, China. Electronic address:
The current surface-enhanced Raman scattering (SERS) substrates typically feature a single energy level, posing challenges in coordinating electromagnetic enhancement (EM) and chemical enhancement (CM), thereby limiting the sensitive detection of numerous crucial target molecules. In this study, novel aggregated nanorings (a-NRs) hybridizing Ag, Au and AgCl are constructed as SERS substrates. On one hand, the obtained a-NRs exhibit robust localized surface plasmon resonance absorption, whose wavelength can be tuned to match three commonly used laser wavelengths (532, 633 and 785 nm) to gain strong EM effect.
View Article and Find Full Text PDFTalanta
December 2024
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China; College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, PR China. Electronic address:
Staphylococcus aureus (S. aureus) has been identified as a indicator of food contamination. In this study, a sensitive and accurate biosensor strategy for S.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, China.
() is the primary risk factor in food safety. Herein, a nanogap-assisted surface-enhanced Raman scattering/polymerase chain reaction (SERS/PCR) biosensor coupled with a machine-learning tool was developed for the direct and specific sensing of S. aureus in milk.
View Article and Find Full Text PDFSci Rep
January 2025
Photonics Research Centre, Universiti Malaya, Kuala Lumpur, 50603, Malaysia.
Two-dimensional (2D) hexagonal boron nitride (hBN) has garnered significant attention due to its exceptional thermal and chemical stability, excellent dielectric properties, and unique optical characteristics, making it widely used in deep ultraviolet (DUV) applications. However, the integration of hBN with plasmonic materials in the visible region (532 nm) has not been fully explored, particularly in terms of morphology regulation and size control of mono- and bimetallic nanoparticles (BMNPs) namely gold (Au), silver (Ag) and Au-Ag. A Schottky junction-based metal-semiconductor contact configuration is employed to achieve hot-carrier reflections on the metal side, enhancing the quantum efficiency of the photodetector.
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