Fluorescent enzyme-linked immunoassay strategy based on enzyme-triggered in-situ synthesis of fluorescent copper nanoclusters
Fluorescent enzyme-linked immunoassay strategy based on enzyme-triggered in-situ synthesis of fluorescent copper nanoclusters
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DOI：
10.1016/j.snb.2018.09.128
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发表时间：
2019-02
期刊：
影响因子：
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通讯作者：
Ruiying Li;Qiang Liu;Yan Jin;Baoxin Li
中科院分区：
文献类型：
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作者：
Ruiying Li;Qiang Liu;Yan Jin;Baoxin Li
常规的酶联免疫吸附试验（ELISA）与比色读数是不适合检测低浓度的目标分子。本文提出了一种以碱性磷酸酶（ALP）为标记酶、铜纳米团簇（CuNCs）为荧光指示剂的灵敏荧光免疫分析方法。在该策略中，ALP特异性地催化抗坏血酸2-磷酸（AAP）水解产生抗坏血酸，然后所得抗坏血酸在DNA模板存在下与Cu 2+相互作用以原位合成荧光DNA模板化的CuNCs。相应的荧光信号与抗体上结合的ALP的量有关，荧光强度可用于通过ELISA平台检测靶抗原。采用人免疫球蛋白G（IgG）作为概念验证的模型抗原，可在0.05 - 12 ng/mL范围内检测到人IgG。检测限为7 pg/mL，远低于以往报道的大多数ELISA方法。这种简单的开启荧光ELISA平台为靶蛋白的灵敏检测提供了一种具有成本效益的方法。
The routine enzyme-linked immunesorbent assay (ELISA) with colorimetric readout is unsuitable for detecting low concentrations of target molecules. Herein, we proposed one sensitive fluorescence immunoassay strategy using alkaline phosphatase (ALP) as the labeling enzyme and copper nanoclusters (CuNCs) as fluorescent indicator. In this strategy, ALP specifically catalyzes the hydrolysis of ascorbic acid 2-phosphate (AAP) to yield ascorbic acid, and then the resultant ascorbic acid interacts with Cu2+in the presence of DNA template to in-situ synthesize the fluorescent DNA-templated CuNCs. The corresponding fluorescence signal is related to the amount of ALP conjugated on antibody, and the fluorescence intensity can be used to detect target antigen through an ELISA platform. Human immunoglobulin G (IgG) is taken as the model antigen for the proof-of-concept, and human IgG could be detected in 0.05 − 12 ng/mL range. The detection limit was 7 pg/mL, which is much lower than those in most of the previously reported ELISA. This simple turn-on fluorescent ELISA platform provides a cost-effective approach for sensitive detection of target proteins.