单颗粒-电感耦合等离子体质谱(ICP-MS)法表征纳米抗菌商品中纳米银颗粒粒径分布

建立了单颗粒-电感耦合等离子体质谱法(Single particle ICP-MS,SP-ICP-MS)测定纳米抗菌商品中纳米银颗粒(Silver nanoparticles,AgNPs)粒度分布的方法。首先采用微波消解-ICP-MS法测定了纳米抗菌商品中的总银含量,确定样品稀释倍数。然后在SP-ICP-MS模式下,测定3种AgNPs标准样品(30、50和80nm)的粒径,所得结果与供应商提供的TEM值接近,说明SP-ICP-MS法能够准确表征水溶液中AgNPs的粒径分布,同时采用SP-ICP-MS测定了纳米抗菌商品中纳米银颗粒粒径分布。方法简单快速、灵敏度高,能够为纳米抗菌材料中AgNPs表征提供准确的表征方法。     

基于单颗粒-电感耦合等离子体质谱法评价聚乙烯抗菌食品包装材料中纳米银颗粒的释放

基于单颗粒-电感耦合等离子体质谱法(SP-ICP-MS)研究了4种市售聚乙烯抗菌食品包装材料中纳米银(AgNPs)的释放行为。采用迭代算法对样品中银离子(Ag⁺)和AgNPs信号进行区分,考察了不同的食品模拟介质(水、 10%(V/V)乙醇、 3%(V/V)乙酸)、环境温度和放置时间等条件对银释放量的影响。结果表明,4种抗菌食品包装材料中总银含量为1.5～125.0μg/g;在聚乙烯食品装材料中存在AgNPs和Ag⁺的释放现象,低温储存可降低银释放量,酸性介质和有机溶剂会促使Ag⁺释放,对AgNPs无明显影响;AgNPs占总银释放量的0.3%～6.1%,其粒径主要分布在50 nm以下。本研究为食品装材料中纳米颗粒物的释放评价提供了依据和方法。     

超声提取-单颗粒电感耦合等离子质谱法测定牙膏中纳米银颗粒

建立了超声提取-单颗粒电感耦合等离子体质谱法(Single particle-inductively coupled plasma-mass spectrometry, SP-ICP-MS)同时测定牙膏中纳米银颗粒(AgNPs)的粒径分布、数量浓度和质量浓度的方法。以0.1%Tx-100超声提取牙膏中的AgNPs,在SP-ICP-MS模式下测定牙膏中AgNPs的粒径分布、数量浓度和质量浓度,考察了方法的最佳提取时间、准确性和检出限。实验结果表明:最佳提取时间为10 min,采用SP-ICP-MS法测定不同粒径的AgNPs标准品,测定结果与标准值一致;方法的粒径检出限、数量浓度检出限和质量浓度检出限分别为23 nm、3.9×10⁸ particles/kg和26 ng/kg;在牙膏样品的加标回收实验中,纳米颗粒回收率在86.6%～93.8%之间。本方法简单、快速,为牙膏中AgNPs的测定提供了准确的方法。     

纳米银的单颗粒-电感耦合等离子质谱法表征及其测定

建立单颗粒-电感耦合等离子体质谱法( SP-ICP-MS)测定稀溶液中纳米银颗粒粒度分布及纳米银颗粒数量浓度的方法。当停留时间为3 ms时,两个或多个纳米银颗粒同时进入检测器的可能性降至最低。采用5倍标准偏差迭代算法(5σ)区分纳米银颗粒信号和背景信号。采用SP-ICP-MS法测定3种商品级纳米银颗粒(30,50和100 nm)粒度分布和纳米颗粒浓度。结果表明：SP-ICP-MS法测定纳米银颗粒结果与纳米银的TEM值相近,可采用SP-ICP-MS法表征纳米银颗粒。本方法测定稀溶液中纳米银颗粒粒度检出限为25 nm,纳米银颗粒浓度检出限约为8×104个/L。将纳米银颗粒加入到自来水样品中并进行测定,获得相近的纳米银粒度分布及纳米颗粒浓度。本方法简单、快捷、灵敏度高,可为研究水环境中纳米银的风险评估提供可靠分析方法,并为饮用水中纳米银的监测提供分析技术。     

基于单颗粒电感耦合等离子体质谱技术的金纳米颗粒准确测定和表征

建立了基于单颗粒电感耦合等离子体质谱(SP-ICP-MS)技术的金纳米颗粒(AuNPs)数量浓度和粒径的准确测定方法,考察了传输效率计算方式、驻留时间、稀释试剂、进样方式等对测定结果的影响。传输效率对结果准确度影响较大,应根据测量目标参数选择传输效率计算方式,并在测定过程中保持传输效率的稳定,利用校准标准对其进行校正。驻留时间的选择直接影响结果的精确程度,应根据样品类型、粒径等性质慎重选择数据处理模式。当驻留时间为0.1 ms时,检测30 nm和60 nm AuNPs的线性范围分别为2～40 pg/g和10～200 pg/g,线性相关系数大于0.9998,数量浓度测定结果的相对标准偏差小于3.80%,颗粒数量浓度和粒径的检出限分别为110 NPs/g和9 nm。对合成的4种AuNPs和国际比对样品分别进行了测定,国际比对样品颗粒数量浓度结果与比对参考值偏差<5%,测定结果等效一致,扩展不确定度<15%(k=2),进一步验证了本方法的准确度和适用性。     

单颗粒-电感耦合等离子体质谱测定海水中银纳米颗粒

建立了单颗粒-电感耦合等离子体质谱法(SP-ICP-MS)量化与表征海水中银纳米颗粒(AgNPs)的方法。筛选了SP-ICP-MS检测海水中AgNPs时的最优驻留时间,通过探究海水基质对AgNPs检测的影响,确定了海水样品稀释倍数,并利用本方法对大连市近岸海域3个站位表层海水样品中的AgNPs进行测定。结果表明,仪器最优驻留时间为100μs, 150倍稀释海水样品可提高AgNPs浓度的测定准确度。本方法测定海水中AgNPs数量浓度检出限为9.75×10³ particles/mL,粒径检出限为12 nm,标称粒径50和100 nm AgNPs的平均加标回收率均大于70%。大连市近岸海域3个站位表层海水样品中均检测出AgNPs,数量浓度最大值为(2.1±0.004)×10⁶ particles/mL,最小值为(1.1±0.01)×10⁵ particles/mL,粒径分布在18～200 nm之间。本方法具有样品制备简单、分析速度快、颗粒物数量浓度检出限低等优点,为近岸海水中AgNPs的监测分析提供了可靠的分析方法。     

酶消解-单颗粒电感耦合等离子体质谱法测定农产品中纳米铂颗粒

铂纳米颗粒在汽车行业中被广泛用作汽车尾气催化剂。随着铂纳米颗粒在工业生产中的广泛应用,它在环境中广泛分布并可能从植物累积进入食物链中。因此,建立一种在农产品中的定量分析方法是至关重要的。以酶消解的前处理方法结合单颗粒-电感耦合等离子体质谱法(Single particle ICP-MS,SP-ICP-MS)测定农产品中纳米铂颗粒(PtNPs)粒径分布及颗粒数量浓度。通过优化前处理提取条件,当Macerozyme R-10酶为10 mg、柠檬酸缓冲溶液浓度为5 mmol/L、提取时间36 h时,农产品中PtNPs提取效果较高。PtNPs粒径检出限为20 nm,颗粒浓度检出限为5×10⁵particle/L,铂颗粒浓度回收率在(81±3)%～(91±4)%,加标后平均粒径(41±3)～(47±2) nm,与50 nm PtNPs标准溶液粒径接近。方法操作简单、检出限低、准确度高,适用于农产品中PtNPs定量分析,为客观评价农产品铂纳米毒性效应提供可靠的分析技术。     

基于单颗粒电感耦合等离子体质谱法测定环境基质水样中纳米银颗粒

采用单颗粒电感耦合等离子体质谱法(SP-ICP-MS)同时测定环境水样中纳米银颗粒(AgNPs)的颗粒浓度、质量浓度和粒径分布,并考察了溶液的pH值、溶解性有机质(DOM)浓度以及离子强度等对AgNPs测定的影响。结果表明：SP-ICP-MS方法对60nmAgNPs标准溶液的测定结果与标准值一致,准确性较好;pH值(5.0~7.0)、离子强度(≤1mmol/L)和DOM浓度(≤30mg/L)对测定结果影响较小;当溶液的pH值≤5.0或离子强度＞1mmol/L时,AgNPs的颗粒浓度和粒径随pH值的下降或离子强度的增强而减小。采用SP-ICP-MS方法测定河水、染料废水、养殖废水3种水样中AgNPs的加标回收率分别为98.1%、83.3%和93.3%,表明该方法在合适的基质条件下可用于快速准确测定环境水样中AgNPs的颗粒浓度、质量浓度和粒径分布。     

基于单颗粒电感耦合等离子体质谱法研究 含纳米银纺织品中银释放行为

利用单颗粒电感耦合等离子体质谱法(Single-particle ICP-MS)研究含纳米银颗粒(AgNPs)纺织品中银的释放行为,系统考察提取液和稀释对测量结果的影响.结果表明,含AgNPs纺织品可同时释放AgNPs和银离子(Ag+),但在模拟汗液和水中的释放行为存在显著差异.在模拟汗液中释放的AgNPs较水中尺寸更...     

热提取乳液进样-单颗粒电感耦合等离子体质谱法测定食品包装材料中的纳米银

建立了热提取乳液进样-单颗粒电感耦合等离子体质谱法测定抗菌包装材料中纳米银颗粒(AgNPs)的方法.采用十氢萘在高温条件下破坏聚乙烯高分子链,提取抗菌包装材料中的AgNPs,通过单颗粒电感耦合等离子质谱法(Single particle-inductively coupled plasma mass spectrome...     

Studying the size/shape separation and optical properties of silver nanoparticles by capillary electrophoresis

This paper describes the feasibility of employing capillary electrophoresis (CE) to separate silver particles in nanometer regimes. We have found that the addition of an anionic surfactant, sodium dodecyl sulphate (SDS), to the running electrolyte prevents coalescence of the silver particles during the process, which improves the separation performance; the concentration of SDS required for optimal silver nanoparticle separation is ca. 20 mM. By monitoring the electropherograms using a diode-array detection (DAD) system, we have also investigated the separation of suspended silver nanorods with respect to their shapes. Our results demonstrate that the combination of CE and DAD is a powerful one for the separation and characterization of various silver nanoparticles.     

Opportunities and challenges of translating direct single impact electrochemistry to high-throughput sensing applications

In this review, we address the opportunities and challenges of single impact electrochemistry as a detection framework applicable beyond the research laboratory. Focusing on the direct detection of nanoparticles, we discuss several aspects essential to the transfer of this technique into applications for ultralow concentration sensing. We cover particle size–dependent sensor performance and engineering approaches for improving mass transfer via microfluidics. Furthermore, we address interfering phenomena such as aggregation, adsorption, and the effect of electrolyte composition.     

Size-fractionation of silver nanoparticles using ion-pair extraction in a counter-current chromatograph

Size separation of silver nanoparticles was investigated in counter-current chromatography (CCC) based on a unique step-gradient extraction process. Carboxylate anions were modified on silver nanoparticles to produce water-dispersible nanoparticles. The aqueous nanoparticles were readily transferred to the organic phase (toluene/hexane = 1:1, v/v) together with the phase transfer catalyst, tetraoctylammonium bromide (TOAB), owing to the ion-pair adduct formation between silver nanoparticle anions and tetraoctylammonium cations. Smaller nanoparticles were found to be more readily transferred to the organic phase compared to larger nanoparticles. Various concentrations of TOAB in the organic elution phase were used in the CCC extraction experiments. It appeared that a concentration of 0.02 mM of TOAB was adequate to achieve optimum separation and recovery for the aqueous Ag nanoparticle sample (1.5 mg) in the CCC extraction experiments. Samples of 15.8 ± 5.3 nm were separated; the distributions of four fractions collected were 13.7 ± 1.9, 14.1 ± 3.5, 19.2 ± 4.3, and 22.2 ± 4.9 nm. Compared with the stepwise extraction performed in this study, the step-gradient extractions using CCC provided much better size discrimination.     

Size sorting of citrate reduced gold nanoparticles by sedimentation field-flow fractionation

Gold nanoparticles (GNPs) have been synthesized through the citrate reduction method; the citrate/gold(III) ratio was changed from 1:1 up to 10:1 and the size of the resulting nanoparticles was measured by sedimentation field-flow fractionation (SdFFF). Experimental data showed that the GNPs size decreases in the ratio range 1:1–3:1 and then increases from 5:1 to 10:1 passing through a plateau region in between, and is almost independent of the precursor solution concentrations. In the zone of minimum diameters the synthetic process does not produce monodispersed GNPs but often multiple distributions, very close in size, are observed as evidenced by the particle size distributions (PSDs) derived from the SdFFF fractograms. UV–vis spectrophotometry, being the most common technique employed in the optical characterization of nanoparticles suspensions, was used throughout this work. A confirmation of the nucleation–aggregation–fragmentation mechanism was inferred from the cross-correlation between UV–vis and SdFFF results.     

Hexazamacrocycle assisted sensing of silver ion through facile synthesis of silver nanoparticles

The ease of generation of silver nanoparticles by using hexazamacrocycle ligand, L1 is utilized for the visual detection of the presence of silver ions at lower concentrations.     

化学还原法制备多形貌银纳米材料

银纳米材料因具有导热导电性能好、光电性能优良及抗菌能力强等优点而引起广泛关注,近年来其制备方法得到广泛研究。已报道的制备方法可分为化学法、物理法和生物法等,其中化学还原法可以通过使用不同的还原剂、包裹试剂及助剂,实现不同形貌及粒径的银纳米材料的快速制备。本文综述了化学还原法制备颗粒状、线形、片状、立方体及其它形貌的银纳米材料的原理及应用,并展望了银纳米材料工业化制备及应用研究的发展趋势。可控制备多形貌银纳米材料对于电子行业、医药生物以及传感器等相关领域的发展具有重要意义。     

Characterization and biocompatibility of chitosan nanocomposites

Chitosan nanocomposites were prepared from chitosan and gold nanoparticles (AuNPs) or silver nanoparticles (AgNPs) of ～5 nm size. Transmission electron microscopy (TEM) showed the NPs in chitosan did not aggregate until higher concentrations (120-240 ppm). Atomic force microscopy (AFM) demonstrated that the nanocrystalline domains on chitosan surface were more evident upon addition of AuNPs (60 ppm) or AgNPs (120 ppm). Both nanocomposites showed greater elastic modulus, higher glass transition temperature (T(g)) and better cell proliferation than the pristine chitosan. Additionally, chitosan-Ag nanocomposites had antibacterial ability against Staphylococcus aureus. The potential of chitosan-Au nanocomposites as hemostatic wound dressings was evaluated in animal (rat) studies. Chitosan-Au was found to promote the repair of skin wound and hemostasis of severed hepatic portal vein. This study indicated that a small amount of NPs could induce significant changes in the physicochemical properties of chitosan, which may increase its biocompatibility and potential in wound management.     

Au/Ag核-壳结构纳米粒子的制备及其SERS效应

随着大量有关表面增强拉曼散射 (SERS)的实验和理论研究的开展 ,金属纳米粒子作为一类重要的 SERS增强介质 ,已引起了人们浓厚的研究兴趣 [1] .而 Au和 Ag作为最常用的活性基底物质 ,更是研究的热点 [2 ,3 ] .最近 ,美国印第安那大学的 Nie等 [4 ] 在单个银纳米粒子上 ,观察到高达 1 0 14 ～ 1 0 15的SERS因子 .同时 ,他们的另外一项工作表明银纳米粒子的形状和大小对 SERS活性有很大影响 [5] .但是 ,由于 Ag溶胶制备的重复性较差 ,且粒度分布不均匀 ,通过控制银颗粒大小而调控 SERS活性是相当困难的[6] .与 Ag相比 ,Au在可见光…     

Quantitative detection of dye labelled DNA using surface enhanced resonance Raman scattering (SERRS) from silver nanoparticles

The detection of dye labelled DNA by surface enhanced resonance Raman scattering (SERRS) is reported. The dye labels used are commercially available and have not previously been used as SERRS dyes. Detection limits using two excitation frequencies were determined for each label. This expands the range of labels which can be used for surface enhanced resonance Raman scattering with silver nanoparticles.