化学
纳米棒
光电流
生物传感器
检出限
劈开
电极
纳米技术
光电子学
DNA
材料科学
色谱法
生物化学
物理化学
作者
Yang Jiao,Weixin Li,Longhua Guo,Fang Luo,Bin Qiu,Zhenyu Lin,Lixin Wang
出处
期刊:Analytical Chemistry
[American Chemical Society]
日期:2022-09-20
卷期号:94 (39): 13575-13581
被引量:14
标识
DOI:10.1021/acs.analchem.2c03230
摘要
TiO2 was grown on both ends of gold nanorods (AuNRs) to form a dumbbell-shaped heterostructure (called AuNRs@end-TiO2) first, and then assembled on the fluorine tin oxide (FTO) electrode surface through hydrophobic interactions to construct a concise photoelectrochemical microRNA-21 (miRNA-21, model target) biosensor using carbon dots (CDs) as photosensitizers. Hairpin probes (HPs) were fixed on the AuNRs@end-TiO2-modified FTO electrode surface through the Au-S bond, and CDs-modified complementary DNA (CDs-cDNA) served as photosensitive probes. In the presence of the target, miRNA hybridized with the HP and triggered double-strand-specific nuclease to cleave the complementary part of the HP with miRNA, and miRNA was released, which can trigger another cycle to realize signal amplification. Many HPs were cleaved and the complementary sequence with cDNA was exposed, which can capture the photosensitive probes to the electrode surface and resulted in photocurrent enhancement. The photocurrent intensity system has a linear relationship with the logarithm of the miRNA concentration in the range of 0.1 fM to 100 pM with a low detection limit of 96 aM (S/N = 3). The biosensor has high sensitivity, good selectivity, and good reproducibility and shows satisfactory results in actual sample detection.
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