Immunoassay of Goat Antihuman Immunoglobulin G Antibody Based on Luminescence Resonance Energy Transfer between Near-Infrared Responsive NaYF4:Yb, Er Upconversion Fluorescent Nanoparticles and Gold Nanoparticles
Immunoassay of Goat Antihuman Immunoglobulin G Antibody Based on Luminescence Resonance Energy Transfer between Near-Infrared Responsive NaYF4:Yb, Er Upconversion Fluorescent Nanoparticles and Gold Nanoparticles
复制标题
基于近红外响应 NaYF4:Yb、Er 上转换荧光纳米粒子和金纳米粒子之间的发光共振能量转移的山羊抗人免疫球蛋白 G 抗体的免疫测定。
DOI：
10.1021/ac901808q
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发表时间：
2009-11-01
影响因子：
7.4
通讯作者：
Xu, Shu-Kun
中科院分区：
文献类型：
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作者：
Wang, Meng;Hou, Wei;Xu, Shu-Kun
近红外（NIR）光可以穿透生物样品甚至组织而不造成样品损伤，并且在荧光检测中避免了生物样品的自身荧光。因此，基于近红外辐射激发的发光共振能量转移（LRET）免疫分析是一种很有前途的生物样品分析方法。本研究利用近红外上转换纳米颗粒（UCNPs）作为能量供体，在近红外照射下可发出可见光；利用金纳米颗粒（Au NPs）作为能量受体，可吸收来自供体的可见光，建立了一种三明治型lret免疫分析法，用于山羊抗人免疫球蛋白G （IgG）的检测。首先制备了氨基功能化的NaYF(4):Yb、Er UCNPs和Au NPs，分别与人IgG和兔抗山羊IgG结合。人igg偶联的NaYF(4):Yb, Er UCNPs （λ (max) = 542 nm）与兔抗山羊igg偶联胶体Au NPs （λ (max) = 530 nm）的nir激发荧光发射带部分重叠，满足LRET供体和受体光谱重叠的要求。然后将山羊抗人IgG加入到人IgG修饰的NaYF(4):Yb、Er UCNPs（供体）和兔抗山羊IgG修饰的Au NPs（受体）的混合物中形成LRET系统。添加的山羊抗人IgG（一抗）与两种不同的蛋白（供体和受体表面的抗原和二抗）之间的三明治式免疫反应架桥了供体和受体，从而缩短了它们之间的间隔，导致近红外照射后从UCNPs到Au NPs发生LRET。因此，nir激发的UCNPs荧光的猝灭与系统中存在的山羊抗人IgG的浓度（在3-67 μ g × mL（-1）范围内）呈线性相关，从而能够检测和定量抗体。这种基于lret的三明治型方法对山羊抗人IgG的检出限很低（0.88 μ g × mL(-1)），说明该方法适用于微量蛋白质的检测。一旦供体和受体纳米颗粒被能够识别目标生物分子的适当分子修饰，这种方法有望扩展到其他生物分子的检测。
Near-infrared (NIR) light can penetrate biological samples and even tissues without causing sample damage and avoid autofluorescence from biological samples in fluorescence detection. Thus, a luminescence resonance energy transfer (LRET)-based immunoassay that can be excited by NIR irradiation is a promising approach to the analysis of biological samples. Here we demonstrate the use of NIR-to-visible upconversion nanoparticles (UCNPs) as an energy donor, which can emit a visible light upon the NIR irradiation, and gold nanoparticles (Au NPs) as an energy acceptor, which can absorb the visible light emitted from the donor, to develop a sandwich-type LRET-based immunoassay for the detection of goat antihuman immunoglobulin G (IgG). Amino-functionalized NaYF(4):Yb, Er UCNPs and Au NPs were first prepared and then conjugated with the human IgG and rabbit antigoat IgG, respectively. The NIR-excited fluorescence emission band of human IgG-conjugated NaYF(4):Yb, Er UCNPs (lambda(max) = 542 nm) partially overlaps with the visible absorption band of the rabbit antigoat IgG-conjugated colloidal Au NPs (lambda(max) = 530 nm), satisfying the requirement of spectral overlap between donors and acceptors for LRET. A LRET system was then formed when goat antihuman IgG was added to a mixture of human IgG-modified NaYF(4):Yb, Er UCNPs (donor) and rabbit antigoat IgG-modified Au NPs (acceptor). The sandwich-type immunoreactions between the added goat antihuman IgG (primary antibody) and the two different proteins (antigen and secondary antibody on the surface of the donors and acceptors, respectively) cross-bridge the donors and acceptors and thus shorten their spacing, leading to the occurrence of LRET from UCNPs to Au NPs upon NIR irradiation. As a result, the quenching of the NIR-excited fluorescence of the UCNPs is linearly correlated to the concentration of the goat antihuman IgG (in the range of 3-67 microg x mL(-1)) present in the system, enabling the detection and quantification of the antibody. Such sandwich-type LRET-based approach can reach a very low detection limit of goat antihuman IgG (0.88 microg x mL(-1)), indicating that this method is applicable for the trace protein detection. This approach is expected to be extended to the detection of other biological molecules once the donor and acceptor nanoparticles are modified by proper molecules that can recognize the target biomolecules.