Noble-metal nanoparticles labeled with fluorescent molecules are used in a variety of applications requiring the measurement of size and diffusion properties of single nanoprobes. We have successfully used intrinsic surface-plasmon-induced photoluminescence (SPPL) signatures of monodispersed bare gold and silver nanoparticles in water to detect and measure their precise diffusion coefficient, concentration and hydrodynamic radius by fluorescence correlation spectroscopy (FCS). Measurement of the effective hydrodynamic radius confirms particle size to be 80 ± 8 and 64 ± 14 nm for gold and silver, respectively, which is in excellent agreement with scanning electron microscopic measurements made on the same particles. Detection of bare gold and silver nanoparticles at the single-molecule level with moderately high value of "per particle brightness" (PPB) confirms those particles to be used as fluorescent probes in biological research and in different medical and biotechnology applications where fluorescence detection plays a vital role. Additionally, these results demonstrate an alternative method for measuring hydrodynamic properties, particularly the size-distribution of bare noble-metal nanoparticles in solution using data-fitting algorithm for FCS based on the maximum entropy method (MEMFCS).
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http://dx.doi.org/10.1366/11-06511 | DOI Listing |
Microorganisms
December 2024
Department of Entomology, Walter Reed Army Institute of Research-Armed Forces Research Institute of Medical Sciences, Bangkok 10400, Thailand.
Leptospirosis, a global zoonotic disease caused by spp., presents high morbidity and mortality risks, especially in tropical regions like Thailand. Military personnel deployed in endemic areas, such as during the Cobra Gold Joint exercise, face heightened exposure.
View Article and Find Full Text PDFNanomaterials (Basel)
January 2025
Department of Applied Chemistry and Institute of Natural Sciences, Kyung Hee University, Yongin-si 17104, Gyeonggi-do, Republic of Korea.
The combination of molybdenum disulfide (MoS) with plasmonic nanomaterials has opened up new possibilities in biological applications by combining MoS's biocompatibility and high surface area with the optical sensitivity of plasmonic metals. These MoS-plasmonic hybrid systems hold great promise in areas such as biosensing, bioimaging, and phototherapy, where their complementary properties facilitate improved detection, real-time visualization, and targeted therapeutic interventions. MoS's adjustable optical features, combined with the plasmon resonance of noble metals such as gold and silver, enhance signal amplification, enabling detailed imaging and selective photothermal or photodynamic therapies while minimizing effects on healthy tissue.
View Article and Find Full Text PDFR Soc Open Sci
January 2025
Department of Experimental Physics, Faculty of Science, Palacký University Olomouc, Olomouc, Czech Republic.
Gold-silver synergism has been well documented in many scientific works dealing with luminescent nanostructures that are exploitable in biomedical and environmental application. Frequently, the ratio of Au : Ag in synthetic mixtures was varied to influence the extent of Au-Ag synergism of the resulting luminescent gold-silver nanoclusters (GSNCs). However, in our approach, a new step, maturing under differing conditions using the same Au : Ag ratio (5 : 1), has been investigated systematically for the very first time.
View Article and Find Full Text PDFFront Oncol
January 2025
Department of Epidemiology and Health Statistics, Xiangya School of Public Health, Central South University, Changsha, China.
Background: Gynecological cancers are characterized by uncontrolled cell proliferation within the female reproductive organs. These cancers pose a significant threat to women's health, impacting life expectancy, quality of life, and fertility. Nanoparticles, with their small size, large surface area, and high permeability, have become a key focus in targeted cancer therapy.
View Article and Find Full Text PDFJ Photochem Photobiol B
January 2025
PG. Department of Chemistry, Pachaiyappa's College for Men, Kanchipuram, Tamilnadu, India.
Green synthesis of metal nanoparticles using plant extracts has emerged as an eco-friendly alternative to conventional methods, offering potential applications in biomedicine and environmental remediation. This study demonstrates the successful biosynthesis of silver nanoparticles (SNPs) and gold nanoparticles (GNPs) using Euphorbia acaulis leaf extract as a reducing and capping agent. The nanoparticles were thoroughly characterized using UV-Vis spectroscopy, HR-SEM, EDX, TEM, AFM, XRD, and FTIR analyses, confirming their successful synthesis and revealing their predominantly spherical morphology with sizes ranging from 1 to 100 nm.
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