免疫纳米金催化共振散射光谱法测定痕量IgM

用粒径为10 nm的金纳米微粒标记羊抗人免疫球蛋白M（IgM）,制备了IgM的免疫纳米金共振散射光谱探针。在pH4.49的KH2PO4-Na2HPO4缓冲溶液及PEG存在下,金标羊抗人IgM与IgM发生特异性结合生成胶体金免疫复合物,离心分离,获得未反应的金标抗上层清液。以此纳米金标抗作为催化剂,在pH 1.93的盐酸-柠檬酸钠缓冲溶液,催化NH2OH·HCl还原吸附在免疫纳米金表面的金络离子物种（AuCl4-）生成粒径更大的金纳米微粒,导致580 nm 处金纳米微粒的共振散射强度急剧增大。结果表明,随着IgM浓度增大,离心上层液中金标抗降低,I 580 nm线性降低,其△I580 nm与IgM浓度在0.06～4.80 ng· ml-1范围内呈良好的线性关系,其回归方程为ΔI580 nm=14.5cIgM + 1.8,检出限为0.03 ng·ml-1。本法具有灵敏、快速和较高的特异性,用于定量分析人血清中IgM,结果满意。     

免疫纳米金催化氯金酸与盐酸羟胺反应：共振散射光谱检测超痕量免疫球蛋白G

用粒径为10nm的金纳米粒子标记羊抗人IgG抗体获得纳米金标记羊抗人IgG抗体（AuGIgG）．在pH2．27的柠檬酸钠-盐酸缓冲溶液中,AuGIgG对氯金酸-盐酸羟胺生成较大粒径金颗粒这一慢反应具有较强的催化作用,该金颗粒在796nm处有一个较强的共振散射峰．在一定条件下,AuGIgG与IgG发生特异性结合生成纳米金免疫复合物,以16000r·min^-1速度离心分离获得未反应的AuGIgG,以它作催化剂催化氯金酸-盐酸羟胺反应生成较大粒径金颗粒,用共振散射光谱做检测技术,建立了测定IgG的免疫共振散射光谱新方法．结果表明,随着IgG浓度增大,离心溶液中AuGIgG浓度降低,I796mn线性降低,其降低值△I796mn与IgG浓度在0．08-16．0ng·mL^-1范围内呈良好线性关系,检出限为0．02ng·mL^-1.本法具有灵敏度高、选择性好和快速等特点,用于定量分析人血清IgG,结果满意．     

痕量铜蓝蛋白的免疫纳米金催化-氧化亚铜微粒共振散射光谱分析

用15 nm的纳米金标记羊抗人铜蓝蛋白抗体(GCP)可获得铜蓝蛋白(CP)纳米金探针(AuGCP). 在pH 7.8柠檬酸-磷酸氢二钠缓冲溶液中, CP与AuGCP发生特异性结合生成胶体金免疫复合物. 离心分离后, 离心液中的AuGCP可作为酒石酸铜(C4H4O6Cu)-葡萄糖反应体系的催化剂, 生成的Cu2O微粒在620 nm处有一共振散射峰. 在选定条件下, 620 nm处共振散射信号降低值△I620 nm与铜蓝蛋白浓度cCP在0.18～45 ng/mL范围内存在良好线性关系, 回归方程为 ΔI620 nm＝2.27cCP＋5.05, 相关系数为0.9940, 检出限为0.14 ng/mL. 该法用于人血清中铜蓝蛋白的检测, 结果满意.     

金纳米微粒共振光散射光谱探针测定维生素B_4-水溶性腺嘌呤的研究

建立了一种以金纳米微粒为探针共振光散射(RLS)法测定维生素B4的新方法.在弱酸性介质中(pH 4.2),金纳米微粒在635 nm有一最大共振散射峰.加入微量维生素B4后,金纳米微粒与维生素B4通过静电引力结合.形成了粒径较大的聚集体,导致RLS强度显著增强.研究了体系的共振光散射光谱特征和反应适宜条件,探讨了共振光散射增强的机理.结果表明,维生素B4质量浓度在0.1～5.0μg/mL 时与散射强度(△I)呈线性关系,检出限(3σ)为12.0 ng/mL,相对标准偏差(RSD)为2.2%.该方法已用于片剂中维生素B4的测定.     

鲱鱼精DNA修饰纳米金催化Fehling反应——共振散射光谱法检测痕量Hg~(2+)

用鲱鱼精DNA(hsDNA)修饰10nm的纳米金制备了Hg2+的hsDNA修饰纳米金共振散射光谱探针(AuhsDNA).在pH7.0Tris-HCl缓冲溶液中及0.017mol/LNaCl存在下,Hg2+与AuhsDNA形成稳定的Hg2+-DNA结合物,引起AuhsDNA中的纳米金析出并聚集形成纳米金簇.该溶液用150nm滤膜过滤后,滤液中过量的AuhsDNA可催化Fehling试剂-葡萄糖反应生成氧化亚铜微粒,该微粒在580nm处有一个较强的共振散射峰.随着汞离子浓度增大,形成的纳米金簇越多,滤液中AuhsDNA越少,生成的氧化亚铜微粒减少,580nm处氧化亚铜微粒的共振散射光强度线性降低,其共振散射光强度降低值ΔI580nm与汞离子浓度在1～833nmol/L范围内成线性,回归方程、相关系数、检出限分别为ΔI580nm2+Hg=0.37C+0.9,0.9990,0.3nmol/LHg2+.该法用于废水中Hg2+的检测.     

免疫纳米金共振散射光谱探针检测痕量免疫球蛋白A

将纳米金的共振散射效应和纳米金标记免疫反应结合起来建立了一种测定免疫球蛋白A的新方法. 采用柠檬酸三钠改良法制备了粒径约为10 nm的纳米金, 用于标记羊抗人免疫球蛋白A获得了免疫球蛋白A (IgA)的免疫共振散射光谱探针. 在pH 5.6的Na₂HPO₄-C₆H₈O₇缓冲溶液和PEG 6000存在下, 金标羊抗人免疫球蛋白A与IgA产生特异性结合, 引起金纳米粒子聚集, 导致金纳米粒子580 nm处的共振散射峰增强. 对免疫分析的条件进行了优化, IgA浓度在0.0054～1.35 μg•mL^－1范围内与580 nm处的共振散射强度呈线性关系, 方法的检测限(3σ)为2.0 ng•mL^－1, 相关系数为0.9983. 用于定量分析人血清中的免疫球蛋白A, 结果满意.     

痕量甲胎蛋白的免疫纳米金催化-氧化亚铜微粒共振散射光谱分析

用粒径15 nm 的纳米金标记单克隆羊抗人甲胎蛋白(GAFP), 制备了甲胎蛋白(AFP)的免疫纳米金探针(AuGAFP). 纳米金及AuGAFP均对葡萄糖还原铜(Ⅱ)生成Cu₂O微粒这一慢反应具有较强的催化作用, Cu₂O微粒在620 nm处产生1个较强的共振散射峰. 将AFP-AuGAFP免疫反应与离心分离技术结合, 建立了超痕量AFP的免疫纳米金催化-Cu₂O微粒共振散射光谱新方法. 随着AFP浓度的增大, AFP-AuGAFP免疫复合物微粒增多, 离心液中AuGAFP浓度降低, 620 nm处的共振散射光强度I_{620 nm}线性降低, 其降低值ΔI_RS与AFP质量浓度ρ(AFP)在0.10～16.0 ng/mL范围内呈现良好的线性关系, 其回归方程为ΔI_RS=4.27ρ(AFP)+1.28, 检出限为0.05 ng/mL. 本方法所用试剂易得, 反应易控制, 灵敏度高, 选择性好, 用于定量分析人血清中的AFP, 结果令人满意.     

金纳米粒子的非线性共振散射及光强度函数研究

液相金纳米粒子在320nm、470nm、580nm720nm处产生四个共振散射峰。它是一种非线性光学介质,当入射光的频率v不同时可获得金纳米粒子的2v倍频、v/2分频、v/3分频、2v/3 分频、3v／2分频散射峰。探讨了影响液相金纳米粒子散射光信号强度I（λ）的主要因素即散射光能量分布、粒径d、△λ（λem-λex)和散射光辐射度Rλex。给出了共振散射光强度与△λ之间的高斯分布函数。建立了一个合理的金纳米粒子的共振散射光强度函数。     

一种新的测定痕量IgG的纳米金标免疫共振散射光谱探针

在pH8.5条件下，用粒径为9nm的金纳米微粒标记羊抗人IgG获得IgG金标免疫探针。在pH5.8磷酸氢二钠-柠檬酸缓冲溶液中及聚乙二醇存在下，金标记羊抗人IgG与人IgG产生特异性结合,羊抗人IgG包裹的金纳米微粒释放出来，聚集形成较大的微粒，导致体系在580 nm处的共振散射峰增强。IgG浓度在1.3~1.5×10³ ng·mL^-1范围内与580 nm处的共振散射光强度增加值呈线性，方法的检出限为0.78ng.mL^-1。该法用于定量分析人血清IgG,，简便快速，结果令人满意。     

免疫金铂纳米合金催化共振散射光谱法测定痕量人绒毛膜促性腺激素

以NaBH₄为还原剂, 制备了金与铂物质的量比为49∶1的金铂纳米合金(GP). 用兔抗人绒毛膜促性腺激素抗体(RhCG)修饰AuPt获得了免疫纳米合金探针(GP-RhCG). 在pH 5.8磷酸氢二钠-柠檬酸缓冲溶液及KCl存在的条件下, GP-RhCG探针发生非特异性聚集, 在590 nm处有一个较强的共振散射峰. 当有人绒毛膜促性腺激素(hCG)存在时, 聚集的GP-RhCG探针与hCG发生特异性结合, 生成分散性较好的GP-RhCG-hCG免疫复合物, 导致590 nm处共振散射峰强度降低. 其共振散射峰强度降低值ΔI_{590 nm}与hCG浓度在6.67～86.7 ng/mL范围内呈现良好线性关系. 免疫反应液中形成的GP-RhCG-hCG免疫复合物对葡萄糖-铜(II)体系具有较强的催化作用, 其产物在610 nm处有一较强共振散射峰. 随着hCG浓度增大, 形成的GP-RhCG-hCG复合物越多, 其催化作用增强, 610 nm处的共振散射峰增强. 其共振散射峰增大值ΔI_{610 nm}与hCG浓度在3.33～133 ng/mL范围内呈线性关系.     

Resonance scattering spectral detection of ultratrace IgG using immunonanogold-HAuCl<Subscript>4</Subscript>-NH<Subscript>2</Subscript>OH catalytic reaction

Nanogold particles of 10 nm were used to label goat anti-human IgG (GIgG) to obtain nanogold-labeled GIgG (AuGIgG). In a citrate-HCI buffer solution of pH 2.27, AuGIgG showed a strong catalytic effect on the reaction between HAuCl₄ and NH₂OH to form big gold particles that exhibited a resonance scattering (RS) peak at 796 nm. Under the chosen conditions, AuGIgG combined with IgG to form immunocomplex AuGIgG-IgG that can be removed by centrifuging at 16000 r/min. AuGIgG in the centrifuging solution also showed catalytic effect on the reaction. On those grounds, an immunonanogold catalytic RS assay for IgG was designed. With addition of IgG, the amount of AuGIgG in the centrifuging solution decreased; the RS intensity at 796 nm (I _{796 nm}) decreased linearly. The decreased intensity ΔI _{796 nm} was linear with respect to the IgG concentration in the range of 0.08–16.0 ng · mL⁻¹ with a detection limit of 0.02 ng · mL⁻¹. This assay was applied to analysis of IgG in sera with satisfactory sensitivity, selectivity and rapidity. Supported by the National Natural Science Foundation of China (Grant No. 20667001), Natural Science Foundation of Guangxi Province (Grant No. 0728213), and the Foundation of New Century Ten-Hundred-Thousand Talents of Guangxi Province     

一种快速高选择性检测痕量癌胚抗原的共振散射光谱法

用10 nm的金纳米粒子标记单克隆癌胚抗原抗体制备了检测癌胚抗原（CEA）的共振散射光谱探针（Au-CEAAb）。在pH 6.8 的Na2HPO4- NaH2PO4缓冲溶液中及聚乙二醇-6000存在下, CEA与Au-CEAAb发生免疫反应聚集形成疏水性的、平均粒径为227.0 nm的免疫复合物微粒,并在321 nm、581 nm产生2个共振散射峰。随着癌胚抗原（CEA）浓度的增大,581 nm处的共振散射强度I581nm线性增加,其增加值△I581nm与CEA浓度在1.0～50.0 ng·mL-1范围内呈良好的线性关系,相应的回归方程、相关系数、检出限(3σ)分别为ΔI581nm=1.63 C +5.6、0.9940、0.52 ng·mL-1。该法简便、快速、灵敏且选择性好,用于检测人血清中癌胚抗原（CEA）,结果满意。     

A highly sensitive and selective immunonanogold resonance scattering spectral assay for sudan I

A sensitive and selective resonance scattering spectral (RSS) assay was proposed for the determination of sudan I (SDI), using 10 nm nanogold to label the antibody against sudan I (anti-SDI Ab) to obtain a RSS probe for SDI. The immunonanogold reaction between nanogold-labelled anti-SDI Ab and SDI took place in pH 4.92 KH₂PO₄–Na₂HPO₄ buffer solution and in the presence of polyethylene glycol (PEG)-6000, and the intensity of resonance scattering peak at 580 nm decreased greatly. The decreased intensity ΔI_{580 nm} was proportional to the concentration of SDI in the range of 0.23–45.0 ng mL^?1. The linear regression equation was calculated as ΔI_580nm = 1.20c + 2.01 (R = 0.9975, n = 6), with a detection limit (3σ) of 0.13 ng mL^?1. The SDI in egg samples was assayed, with satisfactory results.     

A New and Sensitive Catalytic Resonance Scattering Spectral Assay for the Detection of Laccase Activity Using H2O2‐I−‐TDMAC System

In pH 3.8 acetic acid‐sodium acetate (HAC‐NaAC) buffer solution, laccase exhibited a strong catalytic effect on the H₂O₂ oxidation of I ^? to form I₂, and I₂ combined with excess I ^? to form I₃^? that reacted with cationic surfactants of tetradecyl dimethylbenzyl ammonium chloride (TDMAC) to produce the (TDMAC‐I₃)_n association complex particles, which exhibited a strong resonance scattering (RS) peak at 468 nm. Under the chosen conditions, as the concentration of laccase activity increased, the RS intensity at 468 nm (I_{468 nm}) increased linearly. The increased RS intensity ΔI_{468 nm} was linear to laccase activity in the range of 0.08–0.96 U/mL, with a regression equation of ΔI_{468 nm}?88.8U?1.9, and a detection limit of 0.02 U/mL laccase. This proposed method was applied to detect laccase activity in waste water, with satisfactory results.     

鲱鱼精DNA修饰纳米金催化Fehling反应——共振散射光谱法检测痕量Hg2＋

用鲱鱼精DNA (hsDNA)修饰10 nm的纳米金制备了Hg^2＋的hsDNA修饰纳米金共振散射光谱探针(AuhsDNA). 在pH 7.0 Tris-HCl缓冲溶液中及0.017 mol/L NaCl存在下, Hg^2＋与AuhsDNA形成稳定的Hg^2＋-DNA结合物, 引起AuhsDNA中的纳米金析出并聚集形成纳米金簇. 该溶液用150 nm滤膜过滤后, 滤液中过量的AuhsDNA可催化Fehling试剂-葡萄糖反应生成氧化亚铜微粒, 该微粒在580 nm处有一个较强的共振散射峰. 随着汞离子浓度增大, 形成的纳米金簇越多, 滤液中AuhsDNA越少, 生成的氧化亚铜微粒减少, 580 nm处氧化亚铜微粒的共振散射光强度线性降低, 其共振散射光强度降低值?I₅₈₀ nm与汞离子浓度在1～833 nmol/L范围内成线性, 回归方程、相关系数、检出限分别为 ?I_{580 nm}＋0.9, 0.9990, 0.3 nmol/L Hg^2＋. 该法用于废水中Hg^2＋的检测.     

A highly selective nanogold-aptamer catalytic resonance scattering spectral assay for trace Hg using HAuCl4-ascorbic acid as indicator reaction

Single strand DNA (ssDNA) was used to modify nanogold to obtain a nanogold-aptamer resonance scattering (RS) probe (NGssDNA) for Hg²⁺, based on the formation of stable thymine-Hg²⁺-thymine (T-Hg²⁺-T) mismatches and aggregation of the released nanogold particles. After removing the aggregated particles by filtrate membrane, the excess NGssDNA in the filtration solution exhibit catalytic effect on the gold particle reaction between HAuCl₄ and ascorbic acid (AA) that appear as RS peak at 596 nm. When Hg²⁺ concentration increased, the RS intensity at 596 nm decreased. The decreased intensity is linear to Hg²⁺ concentration in the range of 0.00008-0.888 ng/mL Hg²⁺, with detection limit of 0.000034 ng/mL. The nanogold-aptamer catalytic RS assay was applied to determination of Hg²⁺ in water with satisfactory results.     

A highly sensitive resonance scattering spectral assay for IgG using Fehling reagent-glucose-immunonanogold reaction

Nanogold exhibits strong catalytic effect on the slow reaction between glucose and Fehling reagent at 70 °C. The production of Cu₂O particles have two stronger resonance scattering (RS) peaks at 390 nm and 505 nm. The catalytic effect of nanogold-labeled goat anti-human IgG (AuIgG) on the reaction was investigated with the RS technique. Coupled the immunoreaction and the immunonanogold catalytic reaction and centrifugal technique, a highly sensitive and selective RS method was developed for the detection of immunoglobulin G (IgG) as a model. With the concentration of IgG increased, the RS intensity at 505 nm decreased. The decreased intensity at 505 nm ΔI_505 nm was proportional to IgG concentration in the range of 0.13-53.3 ng mL⁻¹, with a detection limit of 0.04 ng mL⁻¹ IgG. This new immunonanogold-catalytic Cu₂O-particle RS bioassay was applied to the determination of IgG in serum sample, with high sensitivity, good selectivity, and low cost.     

A Label-Free Deoxyribozymes Resonance Rayleigh Scattering Assay for Trace Lead(II) Based on Nanogold Catalysis of Chloroauric Acid-Vitamin C Particle Reaction

In pH 7.2 Tris-HCl buffer solution, the substrate strand DNA (SDNA) was hybridized to the enzyme strand DNA (EDNA) forming a double strand DNA (dsDNA). The SDNA in dsDNA could be cleaved by lead(II) to release a cleavaged single-stranded (ssDNA) that prevented the gold nanoparticles (AuNPs) from forming a stable AuNPs-ssDNA conjugate. The unconjugated AuNPs were aggregated to form AuNP aggregation (AuNPsA) that appeared as a resonance Rayleigh scattering (RS) peak at 532 nm. When the lead(II) concentration increased, the AuNPs-ssDNA increased, the AuNPsA decreased, the color changed from blue to red, and the RS intensity at 532 nm decreased. The decreased RS intensity ΔI _532 nm was linear to the lead(II) concentration in the range of 0.67–60 nmol/L, with a detection limit of 0.3 nmol/L. The AuNPs-ssDNA exhibited a strong catalytic effect on the reaction between chloroauric acid and vitamin C (VC) that can be detected by an RS method at 620 nm. When the lead(II) concentration increased, the intensity at 620 nm increased, and the increased intensity ΔI _620 nm was linear to the lead(II) concentration in the range of 1.33–120 pmol/L, with a detection limit of 0.5 pmol/L. The proposed method was applied to detect lead(II) in water samples, with satisfactory results.