gold nanoparticles

Thymidine kinase 1 (TK1) is a marker of cell proliferation that can be used for early screening, treatment monitoring, and evaluating the prognosis of patients with tumors. The main purpose of this study was to develop clinically applicable TK1 antibodies, establish an appropriate detection method, and provide material and technical support for the research and clinical application for different types of tumors. Experimental mice were immunized with the C-terminal 31 peptide of human TK1 to screen monoclonal cell lines capable of stably secreting specific antibodies...

Utilizing electromagnetic hotspots within plasmonic nanogaps is a promising approach to create ultrasensitive surface-enhanced Raman scattering (SERS) substrates. However, it is difficult for many molecules to get positioned in such nanogaps. Metal-organic frameworks (MOFs) are commonly used to absorb and concentrate diverse molecules. Herein, we combine these two strategies by introducing MOFs into plasmon-coupled nanogaps, which has so far remained experimentally challenging. Ultrasensitive SERS substrates are fabricated through the construction of nanoparticle-on-mirror structures, where Au nanocrystals are encapsulated with a zeolitic imidazolate framework-8 (ZIF-8) shell and then coupled to a gold film...

Managing bacterial pathogens in the central nervous system is an immense issue for researchers all around the globe. The problem of these infections remains throughout the population, regardless of the discovery of several possible medicines. The major obstacle to drug delivery is the BBB, but only a few medicines that fulfill demanding requirements can penetrate it. Considering inadequate antibiotic alternatives and the increasing development of resistance, it is more important than ever to find new approaches to address this worldwide problem...

Targeted alpha therapy (TAT) is a methodology that is being developed as a promising cancer treatment using the α-particle decay of radionuclides. This technique involves the use of heavy radioactive elements being placed near the cancer target area to cause maximum damage to the cancer cells while minimizing the damage to healthy cells. Using gold nanoparticles (AuNPs) as carriers, a more effective therapy methodology may be realized. AuNPs can be good candidates for transporting these radionuclides to the vicinity of the cancer cells since they can be labeled not just with the radionuclides, but also a host of other proteins and ligands to target these cells and serve as additional treatment options...

Freeze-based immobilization of deoxyribonucleic acid (DNA) oligonucleotides on gold nanoparticles (AuNPs) is highly efficient for single-stranded oligonucleotides but typically does not accommodate structures such as snap-cooled DNA hairpins (Sc-HPs) and snap-cooled molecular beacons (Sc-MBs) frequently used for biorecognition applications. Recognizing this limitation, we have developed a modified, freeze-based technique specifically designed to enable the adsorption of such hairpin oligonucleotides onto AuNP surfaces while ensuring that they retain their biosensing capabilities...

The development of sustainable and anti-poisoning single-atom catalysts (SACs) is essential for advancing their research from laboratory to industry. Here, we present a proof-of-concept study on the poisoning of Au SACs, and the antidote of Au nanoparticles (NPs), with trace addition shown to reinforce and sustain propylene epoxidation. Multiple characterizations, kinetics investigations, and multiscale simulations reveal that Au SACs display remarkable epoxidation activity at a low propylene coverage, but become poisoned at higher coverages...

Direct analysis of solid samples is always challenging for ionic sensors due to solidified elemental presence and matrix interference. In this work, a "three-phase transforming" technique was first established to make solid sampling elemental sensors and visual detection possible in the future. For Cd transforming from soil samples, a metal ceramic heater (MCH) electrothermal vaporizer (ETV) coupled with a dielectric barrier discharge quartz trap (DBD-QT) was first utilized to fulfill the solid sampling and preconcentration of Cd in soil; for on-site analysis, a colorimetric sensor based on the trithiocyanuric acid (TMT) functionalized gold nanoparticles (AuNPs) was chosen as a chromogenic analysis model...

Extracellular vesicles (EVs) are well-known membrane-limited particles secreted by both healthy and cancerous cells. They are considered as biomarkers for early cancer diagnosis and are involved in many pathologies and physiological pathways. They could serve as diagnostic tools in liquid biopsies, as therapeutics in regenerative medicine, or as drug delivery vehicles. Our aim is here to encapsulate luminescent nanoprobes in the aqueous compartment of human EVs extracted from reproductive fluids. The analysis and labeling of the EVs content with easily detectable luminescent nanoparticles could enable a powerful tool for early diagnosis of specific diseases and also for the design of new therapeutics...

We synthesized Au/Fe3 O4 microparticles. Initially, citrate-capped Fe3 O4 micro-sized particles were synthesized by the co-precipitation method with an excess amount of trisodium citrate. Gold ions were reduced on the surface of citrate-capped Fe3 O4 and grew as gold sub-microparticles with an average diameter of 210 nm on the surface. The characteristic SPR peak of gold nanoparticles on the surface of Fe3 O4 was detected at 584 nm, whereas the absorption in the near-infrared region was increased...

Gold nanorods (AuNRs) with unique optical properties play a pivotal role in applications in plasmonic imaging, small molecule detection, and photothermal therapy. However, challenges in DNA functionalization of AuNRs hinder their full potential due to the presence of a dense cetyltrimethylammonium bromide (CTAB) bilayer, impeding close DNA contact. In this study, we introduced a convenient approach for the rapid assembly of polyadenine (polyA) tailed DNA on AuNRs with control of DNA density, rigidity, and valence...

Identification of protein profiling on plasma exosomes by SERS can be a promising strategy for early cancer diagnosis. However, it is still challenging to detect multiple exosomal proteins simultaneously by SERS since the Raman signals of exosomes detected by conventional colloidal nanocrystals or two-dimensional SERS substrates are incomplete and complex. Herein, we develop a novel three-dimensional (3D) surround-enhancing SERS platform, named 3D se-SERS, for the multiplex detection of exosomal proteins. In this 3D se-SERS, proteins and exosomes are covered with "hotspots" generated by the gold nanoparticles, which surround the analytes densely and three-dimensionally, providing sensitive and comprehensive SERS signals...

Glucose transporter protein-1 (Glut1), is highly expressed in many cancer types and plays a crucial role in cancer progression through enhanced glucose transport. Its overexpression is associated with aggressive tumor behavior and poor prognosis. Herein, the nucleic acids modified gold nanoparticles (AuNPs) was synthesized to deliver small interfering RNA (siRNA) against Glut1 by microRNA 21 (miR-21) triggers toehold-mediated strand displacement reaction for lung cancer starvation therapy. Overexpression of miR-21 triggers toehold-mediated strand displacement, releasing the siRNA to knockdown of Glut1 in cancer cell instead of normal cell...

We examined the effect of deformability of a solid substrate on the kinetics of a surface reaction that occurs between chemical species present in it and a liquid dispensed on it. In particular, we have dispensed aqueous solutions of gold and silver salt as sessile drops or as a liquid pool on a cross-linked film of poly(dimethylsiloxane) (PDMS). The PDMS surface contains organosilane (SiH), which reduces the salt, producing metallic nanoparticles at the solid-liquid interface. These experiments reveal that, for a sufficiently soft solid, the reaction proceeds about three times faster in the drop mode than in the pool mode...

Ultrasmall fluorescent nanomaterials have been widely studied as novel fluorescent probes; however, these nanomaterials are prone to structural damage or aggregation, and the sensitivity and accuracy of most single emission fluorescence probes were very low. Therefore, the controlled synthesis of stable dual-emission ratiometric fluorescence ultrasmall assembly probes still remains a challenge. Herein, star-like polymer unimolecular micelles were utilized as a scaffold template to encapsulate fluorescent ultrasmall carbon quantum dots (CQDs) and gold nanoclusters (AuNCs) via the polymer template directed self-assembly strategy to obtain multiple-responsive ratiometric fluorescent assemblies...

N -Heterocyclic carbenes (NHCs) have emerged as promising ligands for stabilizing metallic complexes, nanoclusters, nanoparticles (NPs) and surfaces. The carbon-metal bond between NHCs and metal atoms plays a crucial role in determining the resulting material's stability, reactivity, function, and electronic properties. Using Raman spectroscopy coupled with density functional theory calculations, we investigate the nature of carbon-metal bonding in NHC-silver and NHC-gold complexes as well as their corresponding NPs...

In this study, gold nanoparticles (AuNPs) were bioreduced from Ajuga bracteosa, a medicinal herb known for its therapeutic properties against various diseases. Different fractions of the plant extract were used, including the methanolic fraction (ABMF), the n-hexane fraction (ABHF), the chloroform fraction (ABCF), and the aqueous extract for AuNPs synthesis. The characterization of AuNPs was performed using UV-Vis spectrophotometry, FT-IR, XRD, EDX, and TEM. UV-Vis spectroscopy confirmed the formation of AuNPs, with peaks observed at 555 nm...

Down-regulator of transcription 1 (DR1) is considered as a biomarker of hashimoto's thyroiditis (HT), which is a risk factor for thyroid cancer. Here, a label-free electrochemical biosensor for DR1 detection was constructed based on polyamidoamine (PAMAM) polymer and the nanocomposite (WO3@AuNPs) composed of tungsten trioxide (WO3) and gold nanoparticles (AuNPs). WO3@AuNPs was obtained by combining monolayer WO3 nanosheets, which has high conductivity, and AuNPs. The modification of WO3@AuNPs can not only increase the conductivity of the electrode but also provide more active sites for signaling units, thus greatly improve the sensitivity of the sensor...

In this research, a cyanobacteria ( Leptolyngbia sp.)-based biological photovoltaic cell (BPV) was designed. This clean energy-friendly BPV produced a photocurrent as a result of illuminating the photoanode and cathode electrodes immersed in the aqueous medium with solar energy. For this purpose, both electrodes were first coated with conductive polymers with aniline functional groups on the gold electrodes. In the cell, the photoanode was first coated with a gold-modified poly 4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)benzamine polymer, P(SNS-Aniline)...

CRISPR therapy for hematological disease has proven effective for transplant dependent beta thalassemia and sickle cell anemia, with additional disease targets in sight. The success of these therapies relies on high rates of CRISPR-induced double strand DNA breaks in hematopoietic stem and progenitor cells (HSPC). To achieve these levels, CRISPR complexes are typically delivered by electroporation ex vivo which is toxic to HSPCs. HSPCs are then cultured in stimulating conditions that promote error-prone DNA repair, requiring conditioning with chemotherapy to facilitate engraftment after reinfusion...

BACKGROUND: Limited chemotherapy efficacy and cancer stem cells (CSCs)-induced therapeutic resistance are major difficulties for tumour treatment. Adopting more efficient therapies to eliminate bulk-sensitive cancer cells and resistant CSCs is urgently needed. METHODS: Based on the potential and functional complementarity of gold and silver nanoparticles (AuNPs or AgNPs) on tumour treatment, bimetallic NPs (alloy) have been synthesized to obtain improved or even newly emerging bioactivity from a combination effect...