Ratiometric SERS biosensor for sensitive and reproducible detection of microRNA based on mismatched catalytic hairpin assembly
Publication date: 15 October 2019Source: Biosensors and Bioelectronics, Volume 143Author(s): Jinyang Chen, Yan Wu, Cuicui Fu, Haiyan Cao, Xiaoping Tan, Wenbing Shi, Zhaoyang WuAbstractMicroRNAs (miRNAs) serve as significant regulators in a variety of diseases and have been emerging as a class of promising biomarkers for early cancer diagnosis. Herein, an enzyme-free surface-enhanced Raman scattering (SERS) platform was proposed for sensitive and reliable detection of target miRNA-21 using a corrective internal standard (IS)-based ratiometric SERS probe coupled with mismatched catalytic hairpin assembly (CHA) amplification. The 4-aminothiophenol (4-ATP) was used as IS molecule and modified on the surface of silver nanoparticles decorated silicon wafer. In principle, the presence of miRNA-21 could cyclically trigger the allosteric effects of mismatched CHA amplification and the 3′-R6G labeled hairpin probe 1 (H1) was opened. Then, the hairpin probe 2 (H2) hybridized with H1 to form H1–H2 complex and the released miRNA-21 was free to participate in the next cycle of CHA reaction. Meanwhile, the H1–H2 complex could hybridize with the capture DNA on the SERS chip, making the Raman tag of R6G close to the surface of SERS substrate, and the intensity of SERS signal from R6G labels increase while that from 4-ATP remain relatively unchanged. Benefiting from outstanding performances of the ratiometric SERS strategy and enzyme-free CHA amplification system, this platfo...
Conclusion RE may mitigate tumor growth and tumor malignancy parameters such as lower histopathological grade, assuming less nuclear pleomorphism and mitotic cells, smaller viable tumor area, and decreased tumor cell proliferation in both adenocarcinomas. In addition, RE induced tumor vascularization.
Authors: Nisker J Abstract Dissolution of Canada's single-tiered health system is now before the Supreme Court of British Columbia and will soon be before the Supreme Court of Canada. If our Supreme Court justices are persuaded to dissolve the Canada Health Act, financially advantaged Canadians will be permitted to purchase privileged access to physicians, diagnostic tests, and surgical facilities. This queue jumping will diminish access for the socioeconomically disadvantaged, among whom women are overrepresented, including women living with disabilities, women of Indigenous heritage, and women who have recently i...
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Duke University researchers found dangerous levels of pulegone in three mint-flavored e-cigarette liquids and warned that the FDA needs to regulate the chemical linked to cancers.
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