DNA template-synthesized silver nanoparticles: A new platform for high-performance fluorescent biosensing of biothiols

Abstract

To develop the high-performance fluorescent bio-sensors, the metal nanoparticles were employed as nanoquenchers and attracted reasonable attention in the design of fluorescent biosensors. In this work, silver nanoparticles (AgNPs) were obtained via reduction of Ag + on FAM-labeled DNA template. For the tight binding between AgNPs and DNA, the template-synthesized AgNPs turned out high quenching efficiency and could be applied as super nanoquenchers to establish the biosensing platform for fluorescent detection. As an example, the template-synthesized DNA-AgNPs conjugates were employed in sensing thiols. By forming S-Ag bonds, thiols interact intensely with AgNPs and replace the FAM-labeled DNA off from the surface of AgNPs, resulting in a fluorescence enhancement. Besides the advantages of lower background and higher signal-to-background ratio (S/B), the conjugates present better stability, making them applicable in complicated biological fluids. To further evidence the feasibility of sensing thiols in real samples, the thiols in human urine were detected. The total amount of free thiols found in human urine was ranging from 229 μM to 302 μM with the proposed sensor. To conclude the reliability, low content of Cys was added and the recovery was 98%-103%. silver nanoparticles, DNA template-synthesized, thiols, fluorescent sensing

Targeted Intracellular Controlled Drug Delivery and Tumor Therapy through in Situ Forming Ag Nanogates on Mesoporous Silica Nanocontainers

“…In 50% FBS, PTX-MSNs@AgNPs is weakly fluorescent due to AgNPs quenching. 18,37,38 However, appreciable emission enhancement is observed as the result of the treatment with GSH, and the intensity increased in a GSH concentration-dependent manner (Figure 2B, inset). Upon addition of 10 μM GSH, physiologically corresponding to the maximum extracellular GSH concentration level, 13 the ROX fluorescence is slightly increased, while a dramatic increase in ROX fluorescence intensity is observed by 5.0 mM GSH, the intracellular GSH concentration level, 39 suggesting that the bound AgNPs were detached from MSNs through a special Ag−S reaction due to the interaction between template-synthesized AgNPs and DNA is much weaker than that of thiol group and silver.…”

“…Specially, these systems suffer from undesirable drug leakage, since the antioxidants exist abundantly not only in tumor cells, but also in extracellular compartments. Different from the previous strategies, the nanogates of our MSNs-based delivery system are obtained by in situ growth of AgNPs on MSNs surface through a DNA template-protected process, − and cargo release from the nanopores is achieved by selective detachment of the AgNPs by GSH-mediated ligand exchange process, that is, a special Ag–S interaction. − Importantly, through in situ formation, the hybrid AgNPs are easily optimized to ensure drug release triggered only by a high concentration of intracellular GSH and species, as well as lower drug leakage in the biological system. Although significant research progress has been made in developing various functionalized MSNs-based materials for drug delivery and biosensing applications, ,, several unique functions and features have been incorporated into the present system to deliver drugs in an optimal fashion.…”

Metal Nanoparticle–Microbe Interactions: Synthesis and Antimicrobial Effects

“…[ 137 ] Indeed, the bases G and A can act as relay stations in the DNA for the transport of holes, while C and T are used for excess electron transfer [ 138 ] and this process should possibly be kept in mind and studied in more detail for the examples mentioned in this review in which DNA is discussed as playing a crucial role in or during the metal ion reduction or coordination. [ 139–141 ]…”

A study of the catalytic ability of in situ prepared AgNPs–PMAA–PVP electrospun nanofibers

“…Nano-silvers, similar to other nanoparticles, [32][33][34] exhibit surface effects, catalytic performance and other special properties, which significantly depend on the particle size, specific surface area, as well as their state and shape. In such cases, the composite nanofibers produced by nanoparticles obtained by electrospinning are thought to exhibit high catalytic activity as a result of the fibers exhibiting large specific surface areas and high porosity.…”