- 标题
- 摘要
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- 实验方案
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A phenylboronate-based SERS nanoprobe for detection and imaging of intracellular peroxynitrite
摘要： A surface-enhanced Raman scattering (SERS) based nanoprobe was developed for detection and imaging of endogenous peroxynitrite in living cells. The probe was fabricated by assembling 3-mercaptophenylboronic acid pinacol ester onto the surface of gold nanoparticles (AuNPs). The detection of peroxynitrite is accomplished via measurement of the changes in the SERS spectra (at 882 cm?1) that are caused by the reaction between probe and peroxynitrite. The probe has a fast response (<30 s), a 0.4 μM lower detection limit and a wide linearity range from 5.0 × 10?7 to 1.0 × 10?4 M. It is biocompatible and highly stable on storage and under various pH conditions. Both the reaction and the SERS signal are highly specific over other species. The nanoprobe was successfully applied to SERS imaging of peroxynitrite that is produced in macrophages under oxidative stress. Conceivably, the method has a most viable tool for use in studies on peroxynitrite-related physiological and pathological processes.
关键词： Surface-enhanced Raman scattering,Boronate ester,Specific reaction,Reactive oxygen species,Gold nanoparticles,Living cell,Oxidative stress,Biosensor
更新于2025-09-23 15:19:57
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Microtubule network as a potential candidate for targeting by gold nanoparticle-assisted photothermal therapy
摘要： Photothermal therapy is achieving ever-increasing attention as a promising method for killing cancer cells. Although, gold nanoparticles are regarded as one of the most effective photothermal therapy agents, the mechanisms underlying their action have to be addressed. Moreover, studies have showed that gold nanoparticles induce apoptosis in treated cultures. Hence, in this study, we investigated the interaction of folic acid functionalized gold nanoparticles and gold-shelled Fe3O4 nanoparticles with microtubule and microtubule associated protein tau in order to introduce intracellular targets of these nanoparticles and provide a holistic view about the mechanism of action of gold nanoparticles used in photothermal therapy. Various spectroscopic methods were used to find gold nanoparticles interaction with Tubulin and Tau. Our results indicated that these gold nanoparticles interact with both Tau and Tubulin and their affinity increases as temperature rises. Also, the results illustrated that quenching mechanism for gold nanoparticles interaction with Tubulin and Tau was static. The hydrophobic interaction was determined as driving force for gold nanoparticles binding to Tubulin and Tau. Moreover, it was showed that both type of gold nanoparticles stabilize microtubule polymers. These results suggest Tau and Tubulin as intracellular target of gold nanoparticles and propose that microtubule network is at the heart of apoptosis mechanisms initiated by photothermal therapy.
关键词： Gold-shelled Fe3O4 nanoparticles,Tubulin,Gold nanoparticles,Tau protein,Photothermal therapy
更新于2025-09-19 17:15:36
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Surface Plasmon Enhanced Light Scattering Biosensing: Size Dependence on the Gold Nanoparticle Tag
摘要： Surface plasmon enhanced light scattering (SP-LS) is a powerful new sensing SPR modality that yields excellent sensitivity in sandwich immunoassay using spherical gold nanoparticle (AuNP) tags. Towards further improving the performance of SP-LS, we systematically investigated the AuNP size effect. Simulation results indicated an AuNP size-dependent scattered power, and predicted the optimized AuNPs sizes (i.e., 100 and 130 nm) that afford extremely high signal enhancement in SP-LS. The maximum scattered power from a 130 nm AuNP is about 1700-fold higher than that obtained from a 17 nm AuNP. Experimentally, a bio-conjugation protocol was developed by coating the AuNPs with mixture of low and high molecular weight PEG molecules. Optimal IgG antibody bioconjugation conditions were identified using physicochemical characterization and a model dot-blot assay. Aggregation prevented the use of the larger AuNPs in SP-LS experiments. As predicted by simulation, AuNPs with diameters of 50 and 64 nm yielded significantly higher SP-LS signal enhancement in comparison to the smaller particles. Finally, we demonstrated the feasibility of a two-step SP-LS protocol based on a gold enhancement step, aimed at enlarging 36 nm AuNPs tags. This study provides a blue-print for the further development of SP-LS biosensing and its translation in the bioanalytical field.
关键词： signal amplification,surface plasmon resonance,gold nanoparticles,surface plasmon enhanced light scattering,gold enhancement
更新于2025-09-19 17:15:36
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Split aptamer based sensing platform for adenosine deaminase detection by fluorescence resonance energy transfer
摘要： In this paper, a split aptamer based fluorescence resonance energy transfer (FRET) platform was constructed for the determination of adenosine deaminase (ADA) activity by using gold nanoclusters (AuNCs) and gold nanoparticles (AuNPs). A single adenosine triphosphate (ATP) aptamer was split into two fragments (referred to as P1 and P2). P1 was covalently attached to the AuNCs at the 5′ end (P1-AuNCs), and P2 was labeled with AuNPs at the 3′ end (P2-AuNPs). In the presence of ATP, ATP bound with the two fragments with high affinity to link P1-AuNCs and P2-AuNPs together, thus the fluorescence of P1-AuNCs was quenched via FRET from P1-AuNCs to P2-AuNPs. With the addition of ADA, ATP was transformed into inosine triphosphate (ITP), and then P1 and P2 were released to cause the fluorescence recovery of the system. So a split aptamer based FRET platform for ADA detection can be established via the fluorescence intensity change of the system. This platform showed a good linear relationship between the fluorescence intensity and ADA concentration in the range of 2-120 U L-1, and the limit of detection (LOD) was 0.72 U L-1. Moreover, the detection of ATP in human serum sample demonstrated the accuracy and applicability of the method for ADA detection in real sample.
关键词： Split aptamer,Gold nanoclusters,Adenosine deaminase,Fluorescence,Gold nanoparticles
更新于2025-09-19 17:15:36
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Development of <i>Lactobacillus kimchicus</i> DCY51 <sup>T</sup> -mediated gold nanoparticles for delivery of ginsenoside compound K: <i>in vitro</i> photothermal effects and apoptosis detection in cancer cells
摘要： We report a non-covalent loading of ginsenoside compound K (CK) onto our previously reported gold nanoparticles (DCY51T-AuCKNps) through one-pot biosynthesis using a probiotic Lactobacillus kimchicus DCY51T isolated from Korean kimchi. The ginsenoside-loaded gold nanoparticles were characterized by various analytical and spectroscopic techniques such as field emission transmission electron microscopy (FE-TEM), energy-dispersive X-ray (EDX) spectroscopy, elemental mapping, X-ray powder diffraction (XRD), selected area electron diffraction (SAED), Fourier-transform infrared (FTIR) spectroscopy and dynamic light scattering (DLS). Furthermore, drug loading was also determined by liquid chromatography–mass spectrometry (LC–MS). In addition, DCY51T-AuNps and DCY51T-AuCKNps were resistant to aggregation caused by pH variation or a high ionic strength environment. Cell-based study confirmed that DCY51T-AuCKNps exhibited slightly higher cytotoxicity compared to ginsenoside CK treatment in A549 cells (human lung adenocarcinoma cell line) and HT29 (human colorectal adenocarcinoma cell line). Upon laser treatment, DCY51T-AuCKNps showed enhanced cell apoptosis in A549, HT29 and AGS cells (human stomach gastric adenocarcinoma cell line) compared with only DCY51T-AuCKNps treated cells. In conclusion, this preliminary study identified that DCY51T-AuCKNps act as a potent photothermal therapy agents with synergistic chemotherapeutic effects for the treatment of cancer.
关键词： green synthesis,gold nanoparticles,Ginsenoside CK,photoluminescence,photothermal therapy,anticancer activity,drug delivery
更新于2025-09-19 17:15:36
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[BestMasters] Topographic Organization of the Pectine Neuropils in Scorpions (An Analysis of Chemosensory Afferents and the Projection Pattern in the Central Nervous System) || Organised Colloidal Metal Nanoparticles for LSPR Refractive Index Transducers
摘要： This work is focused on optimizing adhesion and distribution of colloidal gold nanoparticles on silanized glass substrates intended as nanostructured plasmonic transducer for sensing applications. This system will be used as platform for subsequent functionalization and/or enzyme immobilization. All preparation steps have been monitored by UV-Vis absorption spectroscopy and X-ray photoelectron spectroscopy (XPS).
关键词： Surface plasmon resonance,Silanized substrate,Gold nanoparticles
更新于2025-09-19 17:15:36
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Plasmonic photocatalysis applied to solar fuels
摘要： The induction of chemical processes by plasmonic systems is a rapidly growing field with potentially many strategic applications. One of them is the transformation of solar energy into chemical fuel by the association of plasmonic metal nanoparticles (M NPs) and a semi-conductor (SC). When the localized surface plasmon resonance (LSPR) and the SC absorption do not match, one limitation of these systems is the efficiency of hot electron transfer from M NPs to SC through the Schottky barrier formed at the M NPs/SC interfaces. Here we show that high surface area 1wt.%Au/TiO2-UV100, prepared by adsorption of a NaBH4-protected 3 nm gold sol, readily catalyzes the photoreduction of carbon dioxide with water into methane under both solar and visible-only irradiations with a CH4 vs. H2 selectivity of 63%. Tuning Au NPs size and titania surface area, in particular via thermal treatments, highlights the key role of the metal dispersion and of the accessible Au-TiO2 perimeter interface on the direct SC-based solar process. The impact of Au NPs density in turn evidences the dual role of gold as co-catalyst and recombination sites for charge carriers. It is shown that the plasmon-induced process contributes up to 20% of the solar activity. The plasmon-based contribution is enhanced by a large Au NP size and a high degree of crystallinity of the SC support. By minimizing surface hydroxylation while retaining a relatively high surface area of 120 m2 g-1, pre-calcining TiO2-UV100 at 450°C leads to an optimum monometallic system in terms of activity and selectivity under both solar and visible irradiation. A state-of-the-art methane selectivity of 100% is achieved in the hot electron process.
关键词： Methane production,Gold nanoparticles,Titania,Selectivity,CO2 reduction,Hot electrons,Plasmonic photocatalysis,Solar fuels
更新于2025-09-19 17:15:36
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Gold Nanoparticle-Based Fluorescent Theranostics for Real-Time Image-Guided Assessment of DNA Damage and Repair
摘要： Chemotherapeutic dosing, is largely based on the tolerance levels of toxicity today. Molecular imaging strategies can be leveraged to quantify DNA cytotoxicity and thereby serve as a theranostic tool to improve the efficacy of treatments. Methoxyamine-modified cyanine-7 (Cy7MX) is a molecular probe which binds to apurinic/apyrimidinic (AP)-sites, inhibiting DNA-repair mechanisms implicated by cytotoxic chemotherapies. Herein, we loaded (Cy7MX) onto polyethylene glycol-coated gold nanoparticles (AuNP) to selectively and stably deliver the molecular probe intravenously to tumors. We optimized the properties of Cy7MX-loaded AuNPs using optical spectroscopy and tested the delivery mechanism and binding affinity using the DLD1 colon cancer cell line in vitro. A 10:1 ratio of Cy7MX-AuNPs demonstrated a strong AP site-specific binding and the cumulative release profile demonstrated 97% release within 12 min from a polar to a nonpolar environment. We further demonstrated targeted delivery using imaging and biodistribution studies in vivo in an xenografted mouse model. This work lays a foundation for the development of real-time molecular imaging techniques that are poised to yield quantitative measures of the efficacy and temporal profile of cytotoxic chemotherapies.
关键词： Cy7MX-loaded gold nanoparticles,DNA repair mechanism,AP-targeted delivery,chemotheranostic,molecular probe,real-time imaging
更新于2025-09-19 17:15:36
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Surface Coverage-Regulated Cellular Interaction of Ultrasmall Luminescent Gold Nanoparticles
摘要： Investigations for accurately controlling the interaction between functional nanoparticles (NPs) and living cells set a long-thought benefit in nanomedicine and disease diagnostics. Here, we reveal a surface coverage-dependent cellular interaction by comparing the membrane-binding and uptake of three ultrasmall luminescent gold NPs (AuNPs) with different surface coverages. Lower surface coverage leads to fast cellular interaction and strong membrane-binding but low cellular uptake, whereas high surface coverage induces slow cellular interaction and low membrane-binding but major cellular uptake. The slight number increase of cell-penetrating peptide on the surface of AuNPs shows improved cellular interaction dynamics and internalization through direct cellular membrane penetration. Furthermore, the different intrinsic emissions resulted from the surface coverage variation, especially the pH-responsive dual emissions, make the AuNPs as powerful optical probes for subcellular imaging and tracking. The findings advance the fundamental understanding of the cellular interaction mechanisms of ultrasmall AuNPs and provide a feasible strategy for the design of functional NPs with tunable cellular interaction by surface regulation.
关键词： ultrasmall gold nanoparticles,surface coverage,imaging,luminescence,cellular interaction
更新于2025-09-19 17:15:36
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Ultrasonic-Enhanced Fabrication of Metal Nanoparticles by Laser Ablation in Liquid
摘要： Laser ablation in liquid (LAL) is known to be a promising method for synthesizing metal nanoparticles. In this study, gold and silver nanoparticles were fabricated by ultrasonic-assisted LAL. Gold and silver plates were ablated using a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, with a wavelength of 532 nm and energy of 26.4 J cm?2, in distilled water in the presence and absence of an ultrasonic ?eld. The fabricated solution was analyzed with an ultraviolet?visible (UV?vis) nanoparticle colloidal spectrometer, a transmission electron microscope (TEM) with energy-dispersive X-ray spectroscopy (EDS), and ζ-potential measurement. The craters on the silver plates were analyzed by a scanning electron microscope (SEM), a laser microscope, and MATLAB to observe their morphology and calculate the volume to obtain the concentration of the fabricated nanoparticle solution. Optical emissions were observed to study the characteristics of the laser. The results showed that ultrasonic-assisted LAL has considerable potential for fabricating superior metal nanoparticles.
关键词： Silver nanoparticles,Ultrasonic-assisted,Nd:YAG laser,Laser ablation in liquid,Gold nanoparticles
更新于2025-09-19 17:13:59