Liu Dingbin, Yang Jie, Wang He-Fang, Wang Zhongliang, Huang Xinglu, Wang Zhantong, Niu Gang, Hight Walker A R, Chen Xiaoyuan
State Key Laboratory of Medicinal Chemical Biology, Collaborative Innovation Center of Chemical Science and Engineering, and Research Center for Analytical Sciences, College of Chemistry, Nankai University , Tianjin, China.
Anal Chem. 2014 Jun 17;86(12):5800-6. doi: 10.1021/ac500478g. Epub 2014 Jun 4.
Ultrasensitive and quantitative detection of cancer biomarkers is an unmet challenge because of their ultralow concentrations in clinical samples. Although gold nanoparticle (AuNP)-based immunoassays offer high sensitivity, they were unable to quantitatively detect targets of interest most likely due to their very narrow linear ranges. This article describes a quantitative colorimetric immunoassay based on glucose oxidase (GOx)-catalyzed growth of 5 nm AuNPs that can detect cancer biomarkers from attomolar to picomolar levels. In addition, the limit of detection (LOD) of prostate-specific antigen (PSA) of this approach (93 aM) exceeds that of commercial enzyme-linked immunosorbent assay (ELISA) (6.3 pM) by more than 4 orders of magnitude. The emergence of red or purple color based on enzyme-catalyzed growth of 5 nm AuNPs in the presence of target antigen is particularly suitable for point-of-care (POC) diagnostics in both resource-rich and resource-limited settings.
由于癌症生物标志物在临床样本中的浓度极低，因此对其进行超灵敏和定量检测是一项尚未解决的挑战。尽管基于金纳米颗粒（AuNP）的免疫测定具有高灵敏度，但它们很可能由于线性范围非常窄而无法定量检测感兴趣的目标。本文描述了一种基于葡萄糖氧化酶（GOx）催化5纳米金纳米颗粒生长的定量比色免疫测定法，该方法可以检测从阿托摩尔到皮摩尔水平的癌症生物标志物。此外，这种方法检测前列腺特异性抗原（PSA）的检测限（LOD）（93 aM）比商业酶联免疫吸附测定（ELISA）（6.3 pM）高出4个多数量级。在存在靶抗原的情况下，基于酶催化5纳米金纳米颗粒生长而出现的红色或紫色特别适用于资源丰富和资源有限环境中的即时检测（POC）诊断。
