基于金纳米团簇类酶活性的比色传感研究

金纳米团簇因具有独特的荧光性能、良好的生物相容性、超小的尺寸和良好的催化活性等特点而备受关注.近年的研究发现,金纳米团簇也具有类似天然酶的生物催化活性,在生物分析领域展现了较好的应用前景.本文详细介绍了金纳米团簇的类酶催化性质,总结了金纳米团簇类酶在比色传感领域中的应用研究进展,包括对不同种类物质如生物小分子、离子、蛋...     

DNA调节纳米金模拟酶活性的癌胚抗原比色检测

本文构建了一个DNA调节纳米金颗粒（AuNPs）过氧化物酶模拟酶活性的比色检测方法,用于癌胚抗原的检测。将癌胚抗原的核酸适配体及其互补链通过碱基互补配对构成双链DNA,修饰在磁性微球负载的纳米金颗粒上,制备出具有可调节过氧化物酶模拟酶活性的生物探针。癌胚抗原被生物探针上的核酸适配体捕获后,在AuNPs表面形成空间位阻效应屏蔽底物,从而抑制了AuNPs的酶活性。且为了指示纳米金颗粒的酶活性,用生物探针催化氧化色源底物3,3′,5,5′-四甲基联苯胺（TMB）显色。TMB颜色随着癌胚抗原浓度的增加而变浅,根据体系650nm处的吸光度与癌胚抗原浓度之间的反比关系实现了对癌胚抗原的测定,线性范围为2~18 ng/mL,检测限达0.375 ng/mL。此外,癌胚抗原浓度超过4.8 ng/mL时,颜色出现了可直接用肉眼判断的显著变化。为使检测更加便携,本文同时设计了倒置磁分离检测管,在管中就能完成纳米探针捕获癌胚抗原、磁分离、洗涤。最优条件下,比色检测体系回收率为99%~100%,与临床检验差异显著性分析表明,t检验低于3.182,无明显差异。     

基于氧化铈双重纳米酶活性的比率型比色传感器检测对氧磷

基于氧化铈(CeO₂)的类有机磷水解酶和类氧化酶活性发展了一种比率型比色传感方法,实现了对氧磷的灵敏、准确检测。具有类有机磷水解酶活性的CeO₂纳米粒子(CeO₂ NPs)可催化对氧磷水解为对硝基苯酚,其在400 nm处有明显吸收峰,溶液体系由无色变为黄色;Ce O₂还具有类氧化酶活性,催化3,3′,5,5′-四甲基联苯胺(TMB)氧化为氧化态TMB,在653 nm处有明显吸收峰,溶液由无色变为蓝色。当目标物对氧磷存在时,400 nm处吸光度(A₄₀₀)增高;同时对氧磷抑制其类氧化酶活性,653 nm处吸光度(A653)降低。基于对氧磷加入前后体系A₄₀₀/A653比值的变化,实现了对氧磷的灵敏、准确检测,检出限为0.03μmol/L(S/N=3)。利用本方法检测了韭菜样品中对氧磷的含量,加标回收率在92.0%～99.2%之间。本研究发展了一种基于CeO₂纳米酶双重活性的比率型比色传感检测方法,为食品中对氧磷残留的灵敏检测提供了新策略...     

基于金纳米粒子光学性质的比色传感器及其在食品安全检测中的应用

对金纳米粒子的合成方法的发展及其现状、金纳米粒子的光学性质及其功能化以及基于金纳米粒子光学性质的比色传感器的原理作了简要的回顾后,对其在食品安全检测领域在近十年间的应用概况作了综述,主要涉及重金属离子、DNA、致病菌、农药残留、抗生素等药物残留、有毒有害化学物质、真菌毒素等检测等七个方面,并对此领域的发展前景作了简要展望(引用文献59篇)。     

非聚集金纳米棒比色传感器测定半胱氨酸

基于半胱氨酸（Cys）中的–SH与Hg2+配合生成稳定的Hg(Cys)₂,有效抑制抗坏血酸（Vc）还原Hg2+生成Hg0,进而抑制Hg0与金纳米棒（AuNRs）纵向部位的Au作用而生成金汞齐,导致AuNRs的纵向等离子体共振（Longitudinal surface plasmon resonance,LSPR）吸收峰红移,相应的吸光度（A）增大,并且伴随着溶液颜色的显著变化,同时随着Cys浓度的增大,吸光度A也逐渐增大,据此建立了一种快速     

基于金纳米颗粒的比色传感体系用于前列腺特异性膜抗原的检测

发展了一种基于金纳米颗粒的比色传感体系用于检测前列腺特异性膜抗原的新方法.实验中合成了带有正电荷的金纳米颗粒,并设计了一段带有负电荷的前列腺特异性膜抗原的底物肽段.该方法基于金纳米颗粒聚集状态不同导致颜色变化的性质以及酶与底物的特异性识别作用,达到前列腺特异性膜抗原的检测.带正电荷的金纳米颗粒与带负电的肽段产生静电相互作用,引起金纳米颗粒的聚集;当体系中加入前列腺特异性膜抗原后,由于前列腺特异性膜抗原与肽段的特异性识别作用,带负电的肽段水解为谷氨酸碎片分子,导致金纳米颗粒的分散,反应体系颜色变化快速、明显.该方法简单、灵敏,线性范围为2～10 nmol/L,检测限为0.5 nmol/L.此外,该方法可用于标准加入法测定尿液中的PSMA.     

基于纳米金比色检测NOS1AP基因单碱基突变

基于单、双链DNA与纳米金颗粒间的不同静电作用, 建立了一种基于颜色反应检测NOS1AP基因单碱基突变的方法. 根据NOS1AP基因的单碱基多态位点设计检测探针、互补靶序列及带有单碱基突变序列寡核苷酸DNA. 室温下, 检测探针分别与互补序列、单碱基突变序列在缓冲液中进行杂交, 再分别加入纳米金溶液以及NaCl溶液. 用肉眼可以观察到纳米金溶液在两种不同杂交溶液中产生明显不同的颜色变化. 这种变化可通过紫外-可见分光光度计测定纳米金溶液的紫外吸收峰值的变化来证实. 实验结果表明, 纳米金溶液在一定浓度NaCl存在的条件下, 对互补双链NOS1AP DNA及单碱基突变NOS1AP DNA呈现出不同的颜色反应及紫外吸收光谱的改变. 此方法可望用于相关疾病的医学诊断及单碱基突变的检测.     

金纳米粒子比色探针检测牛奶及鸡蛋中的三聚氰胺

三聚氰胺能诱导金纳米粒子(AuNPs)团聚,溶液颜色由酒红色变为紫色或蓝灰色.以AuNPs作为比色探针,建立了快速检测牛奶和鸡蛋中三聚氰胺的方法.实验优化得最佳反应条件为:AuNPs粒径13 min、pH=7、反应时间10 min和温度为室温.对样品中常见物质进行了干扰实验.样品经10％三氯乙酸和氯仿提取、离心分离后可...     

“两面神”型金纳米粒子比色检测铁离子的新方法

制备了一种聚乙二醇(PEG)和柠檬酸根不对称修饰的"两面神"型金纳米粒子(Janus AuNPs)比色传感器,并基于此建立了铁离子(Fe~(3+))比色检测的新方法。首先,利用柠檬酸钠还原法制备了粒径相对较大的金纳米粒子,随后,以玻片为基底,将大粒径金纳米粒子修饰在玻片上,利用玻片掩蔽部分柠檬酸根位点,并进一步在金纳米粒子非接触区域上修饰大量PEG链,得到柠檬酸根和PEG不对称修饰的Janus AuNPs。引入Fe~(3+)后,有限区域内的柠檬酸根诱导Janus AuNPs发生定向聚集,形成金纳米粒子寡聚体并在水溶液中保持稳定。Janus AuNPs溶液吸光度比值与Fe~(3+)浓度在1μmol/L～10 mmol/L范围内呈线性变化(y=0.129x+0.317),检出限为715 nmol/L。与同类方法相比,该方法操作简便、灵敏度高,且可极大拓宽检测的线性范围。     

Colorimetric Determination of Lead Using Gold Nanoparticles

A combined homogeneous assay and colorimetric determination method using gold nanoparticles was developed for rapid determination of lead(II) in contaminated natural waters. The presence of lead(II) in the colloidal gold suspension causes a change in the absorbance of the suspension. An increase in the absorption property at 595 nm is accompanied by a change in the size of the gold nanoparticles. High concentrations of lead cause aggregation of the gold colloids. Colloidal gold nanoparticles were synthesized using tannic acid as the reducing agent; this reagent allowed selective determination of lead in 10 µL of water, with a detection limit of 310 ng mL^?1 with an analysis time of 5 min. The coefficient of variation for lead(II) within the working range of the assay (520 ng mL^?1–13 µg mL^?1) varied from 1.3% to 9.2%. The limit of detection using this method with a sample volume of 50 µL was 60 ng mL^?1. The coefficient of variation for lead over the working range of the determined concentrations (80 ng mL^?1–25 µg mL^?1) varied from 0.2% to 9.3%, while the values for the inter-day assay (n = 8) were less than 10%. The method was employed for the analysis of river, lake, marsh, and spring water; the recovery of lead was determined to be 72.5%–130% for 10 µL of water and 93.6%–114.7% for 50 µL.     

Highly Selective Colorimetric Detection of Copper Ions Using Cysteamine Functionalized Gold Nanoparticles

In this study, we designed a system of integrating gold nanoparticles and cysteamine to detect Cu2+ based on a colorimetric strategy. The quantified limit of detection towards Cu2+ is 0.4 µM, which is ～50 times lower than the maximum contamination level (～20 µM) in drinking water permitted by US environmental protection agency. The practicality of this system was further validated by detecting Cu2+ in different water samples.     

Electrochemical Sensor Based on Gold Nanoparticles Stabilized in Poly(Allylamine hydrochloride) for Determination of Vanillin

Gold nanoparticles stabilized in poly(allylamine hydrochloride) (AuNP‐PAH) were synthesized, characterized and applied in the development of a new sensor for the determination of vanillin by square‐wave voltammetry. Under optimized conditions, the calibration curve showed a linear range for vanillin of 0.90 to 15.0 µmol L^?1, with a limit of detection of 55 nmol L^?1. The sensor demonstrated acceptable selectivity and stability, as well as good intra‐day and inter‐day repeatability and electrode‐to‐electrode repeatability (with relative standard deviations of 3.5, 4.5 and 3.9 %, respectively). The sensor was successfully applied in the determination of vanillin in different commercial samples.     

基于纳米银的比色阵列传感器的构建及在蛋白质检测中的应用

蛋白质的快速高效检测和鉴定在医学诊断、不同疾病的治疗和蛋白质组学中具有巨大的前景。目前的检测手段大多存在一些问题,如操作繁琐、效率低等,因此开发一个理想的蛋白质检测方法尤为重要。以纳米银(AgNPs)为传感元件的阵列传感器在蛋白质检测方面具有操作便捷、准确率高、可视化等优点。本文合成两种不同颜色和形状的AgNPs:黄色球形和蓝色三角形,以此构建一个简单的比色阵列传感器,用于蛋白质的区分检测。该传感器可以准确地识别和区分不同种类的蛋白质,准确率为100%。在成功识别出不同类型的蛋白质的基础上,进一步评估了该阵列传感器应用于区分正常和变性蛋白质的能力,准确率为96.0%。此外,该阵列传感器对于未知样本的识别也具有高的准确率。     

An Electrochemical Sensor Based on Gold Nanoparticles Incorporated in Mesoporous MFI Zeolite for Determination of Purine Bases in DNA

An electrochemical sensor was developed based on gold nanoparticles incorporated in mesoporous MFI zeolite for the determination of purine bases. Au nanoparticles (AuNPs) were incorporated into the mesoporous MFI zeolite (AuNPs/m‐MFI) by post‐grafting reaction. The composite materials were characterized by transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS) and electrochemical methods. Au nanoparticles with a size of 5‐20 nm are uniformly dispersed in the pores of mesoporous MFI zeolite. And the morphology of MFI zeolite can be perfectly kept after pore expansion and Au nanoparticles incorporation. The electrocatalytic oxidation of purine bases (guanine and adenine in DNA) is investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The surface‐confined Au nanoparticles provide the good catalytic activity for oxidation of purine bases. The simultaneous detection of guanine and adenine can be achieved at AuNPs/m‐MFI composites modified glassy carbon electrode (GCE). The electrochemical sensor based on AuNPs/m‐MFI exhibits wide linear range of 0.5–500 μM and 0.8–500 μM with detection limit of 0.25 and 0.29 μM for guanine and adenine, respectively. Moreover, the electrochemical sensor is applied to evaluation of guanine and adenine in herring sperm DNA samples with satisfactory results.     

基于液体阵列比色传感器鉴别不同茶叶的新方法

基于茶多酚与三价铁的络合性以及对氧化铈的还原性,构建了交叉响应的液体阵列传感器,为茶叶种类的区分提供了一种新方法.利用水热法合成了硅酸锌空心微球和纳米棒作为三价铁的吸附剂,同时合成了可被茶多酚还原的纳米氧化铈,以硅酸锌-硫氰酸铁和氧化铈共同构建3×3阵列.对5种茶多酚和14种茶叶进行了检测,每个样本做5次平行实验,通过聚类分析(HCA)和主成份分析(PCA)方法对反应前后的图谱进行了分析.结果表明,该阵列能够将结构类似的茶多酚化合物准确区分,并且平行样本之间稳定性较好;同时对不同品种的茶叶样本区分效果良好,结合反应前后的差谱图可以实现对茶叶的定性分析.该方法在茶叶品质和食品质量的快速可视化检测方面具有潜在应用价值.     

磺化杯芳烃修饰的金纳米粒的合成及其对多环芳烃的比色检测

通过偶联修饰的方法合成了水溶性磺化杯芳烃修饰的金纳米粒, 并研了其对多环芳烃的比色检测. 结果表明, 磺化杯芳烃修饰的金纳米粒对蒽具有良好的识别选择性. 该比色探针对蒽的检测限可达到2×10-6 mol/L. 这种比色传感器能够实现现场原位检测.     

Colorimetric Sensing of Nitroaromatic Energetic Materials Using Surfactant-Stabilized and Dithiocarbamate-Functionalized Gold Nanoparticles

Abstract

There is an increasing need for sensitive/selective determination of explosive traces in soil and post-blast debris for environmental and criminal investigations. A colorimetric sensor was developed to detect and quantify trinitrotoluene (TNT) and tetryl by the use of surfactant-stabilized and dithiocarbamate-functionalized gold nanoparticles (AuNPs). The sensor was manufactured by modifying the nanoparticles with the cationic surfactant cetyl trimethyl ammonium bromide and incorporating diethyldithiocarbamate (DDTC) in the AuNPs synthesis. DDTC firmly bound to AuNPs may show charge-transfer interactions with the —NO₂ groups of the analytes, and a color change proportional to analyte concentration accompanied the agglomeration of nanoparticles, at which the absorbances were recorded at 534?nm and 458?nm for TNT and tetryl, respectively. Although the limit of detection was 8?mgL^?1 (3.52?×?10^?5?molL^?1) for TNT and 0.8?mgL^?1 (2.78?×?10^?6?molL^?1) for tetryl, providing moderate sensitivity, the cost was greatly reduced compared to those of other thiol-functionalized AuNPs sensors. Possible interferences of other energetic substances in synthetic mixtures, of camouflage materials used in passenger belongings (e.g., detergent, sugar, caffeine, and paracetamol) and common soil ions were also examined. The method was statistically validated against a reference gas chromatography/mass spectrometry method. This sensor may pave the way for the manufacture of novel low-cost nitroaromatic explosive sensors made of DDTC-based pesticides.     

A Sensitive Hydrogen Peroxide Sensor Based on Hemoglobin Immobilized on Gold Nanoparticles and 1,6-hexanedithiol Modified Gold Electrode

Hemoglobin (Hb) was successfully immobilized on a gold electrode modified with gold nanoparticles (AuNPs) via a molecule bridge 1,6-hexanedithiol (HDT). The AFM images suggested that the HDT/gold electrode could adsorb more AuNPs. UV-vis spectra indicated that Hb on AuNPs/HDT film retained its near-native secondary structures. The electrochemical behaviors of the sensor were characterized with cyclic voltammetric techniques. The resultant electrode displayed an excellent electrocatalytical response to the reduction of hydrogen peroxide (H₂O₂). The linear relationship existed between the catalytic current and the H₂O₂ concentration ranging from 5.0 × 10^?8 to 1.0 × 10^?6 mol · L^?1. The detection limit (S/N = 3) was 1.0 × 10^?8 mol · L^?1.