School of Life Sciences, Central South University, Changsha, 410013, China.
School of Life Sciences, Central South University, Changsha, 410013, China.
Anal Chim Acta. 2020 Apr 1;1104:172-179. doi: 10.1016/j.aca.2020.01.014. Epub 2020 Jan 9.
Prostate specific antigen (PSA) is one of the most common biomarkers for the management of prostate cancer. However, it still remains urgent to develop highly sensitive, cost-effective and selective strategies for PSA assay. In this paper, we developed a low-cost, highly sensitive and specific analytical strategy for the detection of PSA by using a fluorescence sensor based on Pb-dependent DNAzyme. We designed a DNA sequence called cmMB with a hairpin structure, containing PSA-specific aptamers and Pb-dependent DNAzyme chains. Also, a fluorophore-labelled DNA sequence called Sub-FAM, which contains a cleavage site of Pb-dependent DNAzyme and serves as substrate, is also designed for the signal generation. In the presence of PSA, interaction between aptamer and PSA blocks the hairpin structure of cmMB, resulting in the formation of Pb-dependent DNAzyme with Pb. Then, Pb-dependent DNAzyme can cleavage Sub-FAM and produce a high fluorescence. In the absence of PSA, since Sub-FAM remains to be ssDNA and can be absorbed by GO, only low fluorescence can be detected. Under optimal experimental conditions, a good linear relationship in the range of 1-100 pg mL was exhibited, with a limit of detection (LOD) of 0.76 pg mL. In addition, the proposed method has potential value in the diagnosis and monitoring of prostate cancer because of its good selectivity and practical application in biological samples.
前列腺特异性抗原（PSA）是前列腺癌管理中最常用的生物标志物之一。然而，开发高度敏感、经济高效且具有选择性的 PSA 检测策略仍然迫在眉睫。在本文中，我们开发了一种基于 Pb 依赖性 DNA 酶的荧光传感器，用于检测 PSA 的低成本、高灵敏度和特异性分析策略。我们设计了一个名为 cmMB 的 DNA 序列，具有发夹结构，包含 PSA 特异性适体和 Pb 依赖性 DNA 酶链。此外，还设计了一个荧光标记的 DNA 序列，称为 Sub-FAM，它包含 Pb 依赖性 DNA 酶的切割位点，并作为信号产生的底物。在 PSA 的存在下，适体与 PSA 之间的相互作用阻止了 cmMB 的发夹结构形成，导致形成含有 Pb 的 Pb 依赖性 DNA 酶。然后，Pb 依赖性 DNA 酶可以切割 Sub-FAM 并产生高荧光。在没有 PSA 的情况下，由于 Sub-FAM 仍然是 ssDNA 并且可以被 GO 吸收，因此只能检测到低荧光。在最佳实验条件下，在 1-100pgmL 的范围内表现出良好的线性关系，检测限（LOD）为 0.76pgmL。此外，由于该方法具有良好的选择性和在生物样品中的实际应用价值，因此在前列腺癌的诊断和监测中具有潜在价值。
