Fast synthesis of gold nanoparticles by cold atmospheric pressure plasma jet in the presence of Au^(+) ions and a capping agent

Homogeneous gold nanoparticles were synthesized under atmospheric pressure using a nonthermal helium plasma jet in a single-step process.A current power supply was used to generate the plasma discharge rich in diverse reactive species.These species induce rapid chemical reactions responsible for the reduction of the gold salts upon contact with the liquid solution.In this study,spherical and monodispersed gold nanoparticles were obtained within 5 min of plasma exposure using a solution containing gold(Ⅲ)chloride hydrate(HAuCl_(4))as a precursor and polyvinylpyrrolidone(PVP)as a capping agent to inhibit agglomerations.The formation of these metal nanoparticles was initially perceptible through a visible change in the sample's color,transitioning from light yellow to a red/pink color.This was subsequently corroborated by UVvis spectroscopy,which revealed an optical absorption in the 520-550 nm range for Au NPs,corresponding to the surface plasmon resonance(SPR)band.An investigation into the impact of various parameters,including plasma discharge duration,precursor and capping agent concentrations,was carried out to optimize conditions for the formation of well-separated,spherical gold nanoparticles.Dynamic light scattering(DLS)was used to measure the size of these nanoparticles,transmission electron microscopy(TEM)was used to observe their morphology and X-ray diffraction(XRD)was also employed to determine their crystallographic structure.The results confirm that homogeneous spherical gold nanoparticles with an average diameter of 13 nm can be easily synthesized through a rapid,straightforward,and environmentally friendly approach utilizing a helium atmospheric pressure plasma.

Biological Interaction and Imaging of Ultrasmall Gold Nanoparticles

Ultrasmall gold nanoparticles(AuNPs)typically includes atomically precise gold nanoclusters(AuNCs)and AuNPs with a core size below 3 nm.Serving as a bridge between small molecules and traditional inorganic nanoparticles,the ultrasmall AuNPs show the unique advantages of both small molecules(e.g.,rapid distribution,renal clearance,low non-specific organ accumulation)and nanoparticles(e.g.,long blood circulation and enhanced permeability and retention effect).The emergence of ultrasmall AuNPs creates significant opportunities to address many challenges in the health field including disease diagnosis,monitoring and treatment.Since the nano–bio interaction dictates the overall biological applications of the ultrasmall AuNPs,this review elucidates the recent advances in the biological interactions and imaging of ultrasmall AuNPs.We begin with the introduction of the factors that influence the cellular interactions of ultrasmall AuNPs.We then discuss the organ interactions,especially focus on the interactions of the liver and kidneys.We further present the recent advances in the tumor interactions of ultrasmall AuNPs.In addition,the imaging performance of the ultrasmall AuNPs is summarized and discussed.Finally,we summarize this review and provide some perspective on the future research direction of the ultrasmall AuNPs,aiming to accelerate their clinical translation.

Applications and safety of gold nanoparticles as therapeutic devices in clinical trials

Use of gold nanoparticles(GNPs)in medicine is an emerging field of translational research with vast clinical implications and exciting therapeutic potential.However,the safety of using GNPs in human subjects is an important question that remains unanswered.This study reviews over 20 clinical trials focused on GNP safety and aims to summarize all the clinical studies,completed and ongoing,to identify whether GNPs are safe to use in humans as a therapeutic platform.In these studies,GNPs were implemented as drug delivery devices,for photothermal therapy,and utilized for their intrinsic therapeutic effects by various routes of delivery.These studies revealed no major safety concerns with the use of GNPs;however,the number of trials and total patient number remains limited.Multi-dose,multicenter blinded trials are required to deepen our understanding of the use of GNPs in clinical settings to facilitate translation of this novel,multifaceted therapeutic device.Expanding clinical trials will require collaboration between clinicians,scientists,and biotechnology companies.

不同尺寸的AuNPs对废水中污染物的催化降解性能

废水中难降解、强毒性污染物的处理仍是目前亟待解决的问题。金纳米颗粒(AuNPs)具有较大的比表面积、良好的催化活性和生物相容性,在废水处理领域获得广泛的关注。然而,AuNPs的催化活性受颗粒尺寸的影响较大。本文采用化学还原法制备出不同尺寸的AuNPs,并分别对废水中污染物铁氰化钾K_(3)Fe(CN)6和对硝基苯酚(4-NP)进行催化降解以探究AuNPs的催化活性。透射电镜(TEM)和紫外-可见吸收光谱(UVvis)表征结果显示,所制备的AuNPs具有与尺寸相关的催化活性,随尺寸的降低催化活性逐渐增强,4 nm的AuNPs能实现200 s内K_(3)Fe(CN)6和4-NP的快速还原,38 nm以上的AuNPs催化性能较低,且在小尺寸区间,催化活性变化更快。此外,AuNPs循环使用6次后仍保持50%以上的催化活性。

Theoretical investigation of F-P cavity mode manipulation by single gold nanoparticles

The ability to manipulate microlaser is highly desirable towards high-performance optoelectronic devices.Here we demonstrate feasible mode manipulation of Fabry-Perot type microlasers of a perovskite nanowire via incorporation of single gold nanoparticles.The influences of resonant wavelength,quality factor and emission directions are successively investigated using a two-dimensional finite-difference time-domain method.It is found that blueshift of resonant wavelength could be achieved together with either promoted or degraded quality factor of the microlaser via single Au NPs with varied sizes.Unidirectional emission could also be realized which is favorable for on-chip integration.Our results provide useful reference for feasible manipulation of light-matter interactions and mode selection.

Molecular fluorescence significantly enhanced by gold nanoparticles@zeolitic imidazolate framework-8

Noble metal nanoparticles exhibit unique surface plasmon resonance dependent optical properties.On this basis,gold nanoparticles(AuNPs)encapsulated in metal–organic frameworks(MOFs)can form AuNPs@MOFs composites to modulate the optical properties of fluorescent molecules,which is less reported.In this paper,based on the fluorescence enhancement effect of AuNPs on 2-(2-hydroxyphenyl)-1H-benzimidazole(HPBI)molecules,zeolitic imidazolate framework-8(ZIF-8)crystals with structural stability were introduced.AuNPs@ZIF-8 exhibited a significantly pronounced fluorescence enhancement of the HPBI molecules.In addition,by comparing the fluorescence characteristics of the HPBI molecules adsorbed on AuNPs@ZIF-8 and those captured in AuNPs@ZIF-8,we found that the ZIF-8 can act as a spacer layer with highly effective near-field enhancement.All our preliminary results shed light on future research on the composite structures of noble metal particles and MOFs for fluorescent probes and sensing applications.

Synthesis and optical properties research of gold nanoparticles with different morphologies

This paper presents an approach to synthesis of gold nanoparticles with different morphologies and investigation of the relationship between morphologies and their optical properties.Spherical gold nanoparticles with different sizes are synthesized via reduction method.Using seed-mediated solution growth method,gold nanoparticles with shuttle,star and stick shapes can be obtained.The sizes and morphologies of the gold nanoparticles are characterized by transmission electron microscopy （TEM）.The characterization results illustrate the growth process of the gold nanoparticles with different morphologies.Absorption spectroscopy and Raman spectroscopy measurements are performed to demonstrate the relationship between the morphologies and optical properties.The results of Raman characterization show that the gold nanoparticles with different morphologies can be used to probe molecules with different concentrations.

基于ZrO_(2)/AuNPs膜修饰电极的适配体传感器用于凝血酶的检测研究

提出了一种简单、无标记、可再生的电化学方法研究适配体和凝血酶之间的相互作用,采用亚甲基蓝(MB)做电化学指示剂,氧化锆(ZrO_(2))-金纳米粒子(AuNPs)涂层修饰玻碳电极(GCE)。利用金-硫键及杂交化学反应,捕获探针和适配体依次修饰到电极表面,亚甲基蓝插入到DNA上,形成适配体传感器。电极表面的DNA双链在凝血酶的存在下发生解旋,MB在DNA上的吸附量随之减少,峰电流也显著降低,达到检测凝血酶的目的。实验显示,凝血酶在20 pmol/L~150 nmol/L的浓度范围内,峰电流的减小量随凝血酶浓度的升高而增大,检出限为20.6 fmol/L。该方法简单、灵敏、选择性好,并成功用于实际样品检测。

Theoretical investigations on CO oxidation reaction catalyzed by gold nanoparticles

It is crucial to understand the mechanism of low temperature CO oxidation reaction catalyzed by gold nanoparticles so as to find out the origin of the high catalytic reactivity and extend the indus‐trialization applications of nano gold catalysts. In this work, some theoretical works on CO adsorp‐tion, O2 adsorption, atomic oxygen adsorption, formation of surface gold oxide films, reaction mechanisms of CO oxidation involving O2 reaction with CO and O2 dissociation before reacting with CO on gold surfaces and Au/metal oxide were summarized, and the influences of coordination number, charge transfer and relativity of gold on CO oxidation reaction were briefly reviewed. It was found that CO reaction mechanism depended on the systems with or without oxide and the strong relativistic effects might play an important role in CO oxidation reaction on gold catalysts. In particular, the relativistic effects are related to the unique behaviors of CO adsorption, O adsorption, O2 activation on gold surfaces, effects of coordination number and the wide gap between the chem‐ical inertness of bulk gold and high catalytic activity of nano gold. The present work helps us to understand the CO oxidation reaction mechanism on gold catalysts and the influence of relativistic effects on gold catalysis.

高表面增强拉曼散射活性rGO-AuNPs的合成及其在氧氟沙星检测中的应用

目的:为氧氟沙星含量检测提供新的研究方向。方法:利用生物质还原法合成具有高表面增强拉曼散射(SERS)活性的还原氧化石墨烯—金复合纳米材料(rGO-AuNPs),通过紫外可见光谱、透射电子显微镜、扫描电子显微镜证明rGO-AuNPs的成功合成,测量并计算其拉曼增强因子(EF)。基于SERS热点效应与核酸适配体的特异性结合能力建立OFL含量检测体系,优化检测条件,建立标准曲线,并将其应用于池塘水样OFL检测中。结果:以百合花瓣生物质成功合成了rGO-AuNPs,金纳米粒子生长在还原氧化石墨烯片层上,EF为3.88×10^(7)。体系SERS强度与氧氟沙星质量浓度在1~500 ng/mL范围内有较好的线性关系,检测限为0.3 ng/mL。加标回收率为96.28%~102.84%,相对标准偏差<10%。结论:合成的rGO-AuNPs具有高SERS活性,在OFL检测方面具有较好的应用前景。

rGO/AuNPs复合物的制备及其对4-硝基苯酚的催化还原性能研究

本文以氧化石墨烯(GO)和氯金酸(HAuCl_(4))为原料,在碱性条件下优化pH值、反应温度、反应时间和HAuCl_(4)浓度,成功制备了还原氧化石墨烯/纳米金(rGO/AuNPs)复合物,并以此为催化剂考察了其在NaBH_(4)存在下对4-硝基苯酚(4-NP)的催化还原性能。rGO/AuNPs复合物的制备条件决定着其中rGO的还原程度和AuNPs的尺寸形貌。在pH=10,HAuCl_(4)浓度为3 mmol/L条件下,90℃反应9 h后得到了还原程度较高的rGO(C/O=5.89),且平均粒径为(14.79±3.86)nm的球形AuNPs均匀分布在rGO表面。rGO/AuNPs复合物对4-NP的催化还原反应表现出良好的催化剂活性。30℃时,在0.1 mol/L(20 mL)的NaBH_(4)存在下,反应20 min后,0.05 mL rGO/AuNPs对0.2 mmol/L(20 mL)4-NP的去除率可以达到98.2%,反应速率常数为0.2358 min^(-1)。研究结果表明,通过简单地控制反应体系pH值制备的rGO/AuNPs复合物具有优异的4-NP催化活性。

Effect of Gold Nanoparticles on the Photocatalytic and Photoelectrochemical Performance of Au Modified BiVO_4

An efficient visible light driven photocatalyst, gold nanoparticles(NPs) modified Bi VO_4(Au/Bi VO_4), has been synthesized by deposition-precipitation with urea method. Au/Bi VO_4 exhibits enhanced photocatalytic activity for phenol degradation underλ>400 nm irradiation but negligible activity underλ>535 nm,indicating that the surface plasmon resonance(SPR) effect is too weak for organic photodegradation. According to the photoelectrochemical results of the porous powder electrodes of Bi VO_4 and Au/Bi VO_4, the SPR effect of Au NPs has been assessed. The role of Au NPs as electron sinks or sources, which is controllable by incident photon energy and applied potentials, has been discussed.

Anisotropic gold nanoparticles: Preparation and applications in catalysis

Despite the high amount of scientific work dedicated to the gold nanoparticles in catalysis, most of the research has been performed utilising supported nanoparticles obtained by traditional impreg‐nation of gold salts onto a support, co‐precipitation or deposition‐precipitation methods which do not benefit from the recent advances in nanotechnologies. Only more recently, gold catalyst scien‐tists have been exploiting the potential of preforming the metal nanoparticles in a colloidal suspen‐sion before immobilisation with great results in terms of catalytic activity and the morphology con‐trol of mono‐and bimetallic catalysts. On the other hand, the last decade has seen the emergence of more advanced control in gold metal nanoparticle synthesis, resulting in a variety of anisotropic gold nanoparticles with easily accessible new morphologies that offer control over the coordination of surface atoms and the optical properties of the nanoparticles （tunable plasmon band） with im‐mense relevance for catalysis. Such morphologies include nanorods, nanostars, nanoflowers, den‐dritic nanostructures or polyhedral nanoparticles to mention a few. In addition to highlighting newly developed methods and properties of anisotropic gold nanoparticles, in this review we ex‐amine the emerging literature that clearly indicates the often superior catalytic performance and amazing potential of these nanoparticles to transform the field of heterogeneous catalysis by gold by offering potentially higher catalytic performance, control over exposed active sites, robustness and tunability for thermal‐, electro‐and photocatalysis.

A Concise Review of Gold Nanoparticles-Based Photo-Responsive Liposomes for Controlled Drug Delivery

The focus of drug delivery is shifting toward smart drug carriers that release the cargo in response to a change in the microenvironment due to an internal or external trigger. As the most clinically successful nanosystem, liposomes naturally come under the spotlight of this trend. This review summarizes the latest development about the design and construction of photo-responsive liposomes with gold nanoparticles for the controlled drug release. Alongside, we overview the mechanism involved in this process and the representative applications.

Improving the performance of solid oxide electrolysis cell with gold nanoparticles-modified LSM-YSZ anode

Gold, as the common current collector in solid oxide electrolysis cell(SOEC), is traditionally considered to be inert for oxygen evolution reaction at the anode of SOEC. Herein, gold nanoparticles were loaded onto conventional strontium doped lanthanum manganite-yttria stabilized zirconia(LSM-YSZ) anode, which evidently improved the performance of oxygen evolution reaction at 800 °C. The current densities at 1.2 V and 1.4 V increased by 60.0% and 46.9%, respectively, after loading gold nanoparticles onto the LSM-YSZ anode. Physicochemical characterizations and electrochemical measurements suggested that the improved SOEC performance was attributed to the accelerated electron transfer of elementary process in anodic polarization reaction and the newly generated triple phase boundaries in gold nanoparticles-loaded LSMYSZ anode.

Fluorescence quenching method for the determination of catechol with gold nanoparticles and tyrosinase hybrid system

The determination method of catechol by fluorescence quenching was developed.The assay was based on the combination of the unique property of gold nanoparticles with tyrosinase enzymatic reaction.In the presence of tyrosinase,the fluorescence of gold nanoparticles was quenched by catechol which can be employed to detect catechol.Under the optimal conditions,a linear range 5.0×10^(-7)-1.0×10^(-3) mol L^(-1) and a detection limit 1.0×10^(-7) mol L^(-1) of catechol were obtained.o-Quinone intermediate produced...

Hesperetin conjugated PEGylated gold nanoparticles exploring the potential role in anti-inflammation and anti-proliferation during diethylnitrosamine-induced hepatocarcinogenesis in rats

Liver cancer is the fifth most common cancer and one of the leading causes of death in the world, and second most common cause of death in men. Natural products emerge as the most enduring approaches in the development of anticancer targeting drug. Hesperetin(HP), one of the abundant flavonoids found naturally in citrus fruits, has received considerable attention in anti-cancer promotion and progression. The present study was conducted to decipher the role of 0.5 ml hesperetin conjugated gold nanoparticles(Au-m PEG(5000)-S-HP NPs) during diethylnitrosamine(DEN)-induced hepatocarcinogenesis in male Wistar albino rats and shows the better antioxidant that possesses anti-inflammatory,anti-proliferation and anticarcinogenic properties and may modulate signaling pathways.The confirmation of polymer functionalized gold nanoparticles and drug loaded polymer gold nanoparticles were characterized by HR-TEM with EDAX, and DLS with Zeta potential techniques. The drug encapsulation efficiency and release properties were carried out in PBS at pH 7.4 for Au-mPEG(5000)-S-HP and compared with the control pure hesperetin(HP).Here, we review the role of mast cell counts, tumor necrosis factor alpha(TNF-α), transcription factor nuclear factor-κB(NF-κB), levels of glycoconjugates, proliferating cell nuclear antigen(PCNA) and argyrophilic nucleolar organizing regions, are the master regulator of inflammation and proliferation, in the development of hepatocellular injury, liver fibrosis and HCC. DEN-administered animals showed increased mast cell counts, tumor necrosis factor alpha, transcription factor nuclear factor-κB, glycoconjugates, proliferating cell nuclear antigen, and argyrophilic nucleolar organizing regions. Whereas Au-mPEG(5000)-S-HP NPs supplementation considerably suppressed all the above abnormalities. These results suggest that the Au-m PEG(5000)-S-HP NPs exhibited the better potential anticancer activity by inhibiting cell inflammation and proliferation in DEN-induced hepatocellular carcinogenesis.

Optical manipulation of gold nanoparticles using an optical nanofiber

Gold nanoparticles are gaining increasing attention due to their biological and medical applications.In this letter,we experimentally demonstrate the optical manipulation of 250-nm-diameter gold nanoparticles along an optical nanofiber（550 nm in diameter） injected by an 808-nm laser light.The nanoparticles situated in the evanescent optical field are trapped by optical gradient force and move along the direction of light propagation due to optical scattering force.The velocities reach as high as 132 μm/s at an optical power of 80 mW.

Efficacy of Gold Nanoparticles against Nephrotoxicity Induced by Schistosoma mansoni Infection in Mice

Objective In this study, the ameliorative effects of gold nanoparticles （gold NP） on the renal tissue damage in Schistosoma mansoni （S. mansoni）-infected mice was investigated. Methods High-resolution transmission electron microscopy was used for the characterization of NP. The gold NP at concentrations of 250, 500, and 1000 μg/kg body weight were inoculated into 5. mansoni-infected mice. Results The parasite caused alterations in the histological architecture. Furthermore, it induced a significant reduction in the renal glutathione levels; however, the levels of nitric oxide and malondialdehyde were significantly elevated. The parasite also managed to downregulate KIM-I, NGAL, MCP-1, and TGF-8 mRNA expression in infected animals. Notably, gold NP treatment in mice reduced the extent of histological impairment and renal oxidative damage. Gold NP were able to regulate gene expression impaired by 5. Mansoni infection. Conclusion The curative effect of gold NP against renal toxicity in 5. mansoni-infected mice is associated with their role as free radical scavengers.

Self-organization of Gold Nanoparticles Protected by 9-(5-Thiopentyl)-carbazole

Through the reduction of [AuCl4] by aqueous sodium borohydride in the presence of 9-(5-thiopentyl)-carbazole, the gold nanoparticles has been prepared and characterized.