RNA-Mediated Fluorescent Q-PbS Nanoparticles

Abstract

RNA-mediated fluorescent PbS nanoparticles have been synthesized in the quantum-confined region of a face-centered cubic phase. The binding of RNA to the surface of PbS nanoparticles has been exploited to tailor its size and to improve the stability and electronic properties. These particles display excitonic features and a relatively strong narrow emission band (fwhm 70 nm) at 675 nm with a broad excitation range extending from 330 to 620 nm. The manipulation of experimental conditions could control the relaxation dynamics of charge carriers in the illuminated particles. The multifunctionality of the RNA structure contributes to the observed electronic properties in a cooperative manner. Such biopolymeric nanostructures may find tremendous applications in the fabrication of solar cells, fluorescence imaging, and detection devices.

Facile Synthesis of High‐Quality, Water‐Soluble, Near‐Infrared‐Emitting PbS Quantum Dots

“…However, in previous reports on PbS, most of the synthetic efforts yielded irregularly shaped PbS nanocrystals; [29] few synthetic approaches were carried out to prepare spherical PbS QDs, [30][31][32][33] especially water-soluble spherical PbS QDs. [34] So far, only the group of Kumacheva succeeded in synthesizing highly luminescent PbS QDs in aqueous medium, by using a mixture of thioglycerol (TGL) and dithioglycerol (DTG) as the capping agents, which indicates that the direct aqueous synthesis of PbS QDs is very difficult because of the lack of suitable stabilizers.…”

Synthesis of PbS/Cu2S/ZnS nanoparticles and their optical properties

“…For example, the addition of a ZnS shell induces the absorption coefficient of PbS/ZnS nanoparticles to decrease in wavelength to the range of 350-500 nm from the absorption wavelength value of pure PbS nanoparticles of 600 nm, which results in a blue shift of the absorption signal. 26,29 The PL spectra for the material in this study reveals a blue shift for the core/shell system compared to the original PbS nanoparticles, where the relaxation dynamics of the charge carriers is influenced by the passivation of the surface, thereby enhancing the life-time and increasing the QY values. 29 This phenomena has been observed on systems that contain PbS nanoparticles, and has been attributed to PbS confinement.…”

“…26,29 The PL spectra for the material in this study reveals a blue shift for the core/shell system compared to the original PbS nanoparticles, where the relaxation dynamics of the charge carriers is influenced by the passivation of the surface, thereby enhancing the life-time and increasing the QY values. 29 This phenomena has been observed on systems that contain PbS nanoparticles, and has been attributed to PbS confinement. Even for increased particle sizes that normally produce a red shift in the absorption spectrum, heterostructures with a small conduction-band offset and a large valence-band offset suggest that electron wave functions extend into the ZnS shell while holes are efficiently confined in the PbS/Cu 2 S core, thereby reducing the electron-hole overlap that produces the blue shift observed in most of these types of systems.…”

Antibacterial Effect of Seidlitzia rosmarinus Extract and Silver Nanoparticles on Staphylococcus aureus and Klebsiella pneumoniae Isolated from Urinary Tract Infections

“…In many studies, antibacterial properties of nanoparticles such as Chromium, Iron, Zink, Silver, and their oxides has been proven (2). Silver, in nano-dimensions, influences the metabolism, respiration, and reproduction of microorganisms.…”