DNA assembly of silicon quantum dots/gold nanoparticle nanocomposites

Abstract

Silicon quantum dots (Si-QDs) dispersible in water and exhibiting bright near infrared (NIR) luminescence are a very attractive nano-light-emitter usable in bioimaging and biosensing. Here, we demonstrate fabrication of NIR luminescent nanocomposites composed of Si-QDs and gold nanoparticles (Au-NPs) by DNA hybridization. We first develop processes to functionalize the surface of Si-QDs by different types of silane coupling agents without notably affecting the water solubility and the luminescence properties, and then conjugate the functionalized Si-QDs with single-stranded DNA (ssDNA). DNA hybridization with a Au-NP with complementary ssDNA results in the formation of Si-QDs / Au-NP nanocomposites.Semiconductor quantum dots (QDs) with size-tunable photoluminescence (PL) have been intensively studied as nanoprobes for biomedical applications 1-4 due to the high chemical and photophysical properties compared to organic dyes and fluorescent proteins. 5 However, toxic heavy metal

Silicon Nanocrystals and Their Composites: Syntheses, Fluorescence Mechanisms, and Biological Applications

“…It was found that the plasmon resonance on the surface of Au NPs could improve the PL intensity of Si NC, and the enhancement factor of the PL intensity approaches the maximum when the shell thickness was 10 nm. The same group also successfully prepared Si NCs/AuNP nanocomposites by DNA hybridization, which is expected to be applied to biosensing …”

Multifunctional 3D Hierarchical Bioactive Green Carbon-Based Nanocomposites

“…The inhibition of the physical interaction ability would be because of attaining a state of physical saturation that leads to J-aggregations 102−104 as well as considerable agglomeration of the nanocomposites and the genetic material. 52,105,106 Further investigations were conducted to evaluate the cytotoxicity (after the treatment time of 72 h) and biocompatibility of the synthesized nanoparticles as well as the role of each part (Figure 9). In this case, two cell lines were selected, PC12 and HEK-293, and the rGO/MWCNT/Fe 3 O 4 / ZnO nanocomposite, rGO/MWCNT/Fe 3 O 4 part, along with the role of addition of different concentrations of ZnO as (+a) and (+b) in the presence of CRISPR/Cas9 was screened.…”

“…However, by decreasing the mentioned ratio, the EGFP increased up to 11%, which is unprecedented among similar compounds and the highest recorded among nanocomposites (Figure b). − In addition, in the absence of the ZnO compartment, the EGFP trends were contrariwise, which showed the effect of ZnO nanoparticles on the morphology and step sizes of the final nanocomposite as the active interaction sites. − The reason for this observation could be due to the physical interaction between those nanocomposites and CRISPR/Cas9 as well as the AFM results, which indicates that by increasing the ratio of nanocomposite to CRISPR/Cas9, the size of the final nanoplex enhanced considerably as well as the ability of the nanocomposite to make a suitable physical interaction with the CRISPR/Cas9 was inhibited significantly. The inhibition of the physical interaction ability would be because of attaining a state of physical saturation that leads to J -aggregations − as well as considerable agglomeration of the nanocomposites and the genetic material. ,, …”

Growth of Core–Shell Silicon Quantum Dots in Borophosphosilicate Glass Matrix: Raman and Transmission Electron Microscopic Studies

“…31 Therefore, the codoped Si QDs have a core-shell structure consisting of a crystalline Si core and an amorphous shell made of B, Si and P (amorphous B x Si y P z shell). The amorphous B x Si y P z shell is responsible for many superior properties of codoped Si QDs such as hydrophilicity, 30 high resistance to HF etching, 27 stable luminescence in different environment, e.g., in water 30 and in air, 32 robustness of the luminescence for chemical treatments, 33 etc.…”