Key Laboratory of Biomedical Engineering of Fujian Province, Department of Biomaterials, College of Materials, Xiamen University, Xiamen, 361005, China.
Department of Physics, Research Institute for Biomimetics and Soft Matter, Fujian Provincial Key Laboratory for Soft Functional Materials, Xiamen University, Xiamen, 361005, China.
Biosens Bioelectron. 2020 Oct 15;166:112424. doi: 10.1016/j.bios.2020.112424. Epub 2020 Jul 11.
Colorimetric biosensors have attracted wide attention due to their low cost, simple operation, rapid response and good reproducibility. However, insufficient sensitivity limits their applications. This report describes the design of a colorimetric biosensor based on a three-step multiple signal amplification strategy to detect breast cancer-associated BRCA1 mutation. The capture unit, signal unit, and target DNA form a sandwich construction. The signal probes are immobilized on the surface of nanomaterials to form the signal unit, which can catalyze the reduction of a colorimetric substrate 4-nitrophenol (4-NP). Firstly, 0D gold nanoparticles (AuNPs) are employed to catalyze 4-NP reduction and reaches 10-fold signal amplification. Then AuNPs are decorated on the surface of 2D material, such as graphene oxide (GO), the catalytic efficiency is further enhanced to 10-fold signal amplification. The third step amplification is achieved by replacing stable GO with oxidizable 2D material (BiSe nanosheets), resulting in a nearly 10-fold amplification. The sandwich-type BiSe-AuNPs biosensor shows excellent sensitivity and selectivity. The detection limit can reach up to 10 M and there is a good linear relationship between the reaction kinetics constant and the DNA concentration in the range of 10-10 M. In addition, one-base mismatch, two-base mismatch and non-complementary sequences can be distinguished clearly by this biosensor. This design may have beneficial clinical application prospects for cancer genetic screening and early diagnosis.
比色生物传感器由于其成本低、操作简单、响应迅速、重现性好而受到广泛关注。然而，其灵敏度不足限制了它们的应用。本报告介绍了一种比色生物传感器的设计，该传感器基于三步多重信号放大策略，用于检测与乳腺癌相关的 BRCA1 突变。捕获单元、信号单元和靶 DNA 形成三明治结构。信号探针固定在纳米材料表面形成信号单元，可催化比色底物 4-硝基苯酚（4-NP）的还原。首先，0D 金纳米粒子（AuNPs）用于催化 4-NP 的还原，达到 10 倍的信号放大。然后 AuNPs 被修饰在二维材料（如氧化石墨烯（GO））的表面，催化效率进一步增强，达到 10 倍的信号放大。第三步放大是通过将稳定的 GO 替换为可氧化的二维材料（BiSe 纳米片）实现的，导致近 10 倍的放大。三明治型 BiSe-AuNPs 生物传感器具有优异的灵敏度和选择性。检测限低至 10-10 M，在 10-10 M 的范围内，反应动力学常数与 DNA 浓度之间呈良好的线性关系。此外，该生物传感器可以清楚地区分单碱基错配、双碱基错配和非互补序列。这种设计可能对癌症遗传筛查和早期诊断具有有益的临床应用前景。
