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The article details a groundbreaking platform for detecting microRNAs (miRNAs), crucial biomolecules involved in gene regulation and linked to various diseases. This innovative platform combines the CRISPR-Cas13a system's precise ability to specifically target and cleave RNA molecules with the amplification capabilities of the hybridization chain reaction (HCR). HCR aids in signal enhancement by creating branched DNA structures. Additionally, the platform employs electrochemiluminescence (ECL) for detection, noted for its high sensitivity and low background noise, making it particularly effective. A key application of this technology is in the detection of miR-17, a biomarker associated with multiple cancer types. It exhibits remarkable detection capabilities, characterized by low detection limits (14.38 aM) and high specificity. Furthermore, the platform's ability to distinguish between similar miRNA sequences and accurately quantify miR-17 in cell lysates underscores its significant potential in clinical and biomedical fields. This combination of precise targeting, signal amplification, and sensitive detection positions the platform as a powerful tool for miRNA analysis in medical diagnostics and research. [Display omitted] • Construction of a novel sensing platform to realize the detection of miRNAs. • This research strategy combines CRISPR-Cas13a with HCR for detection by ECL methodology. • Highly sensitive and specific in miR-17 detection, with low detection limits (14.38 aM). • This research strategy has a very high potential for clinical and biomedical applications. [ABSTRACT FROM AUTHOR]

Glypican-3 (GPC3) is a heparan sulfate proteoglycan (HSPG) that binds to the cell membrane via glycosylphosphatidylinositol (GPI). It is not found in healthy adult liver but is overexpressed in human hepatocellular carcinoma (HCC). The protein marker GPC3 on extracellular vesicles (GPC3+ EVs) is also useful for HCC detection. Nevertheless, the absence of practical and dependable quantitative techniques to evaluate EVs proteins prevents their clinical implementation. Here, using an immuno-recombinase polymerase amplification (immuno-RPA) process and dual amplification of clustered regularly interspaced short palindromic repeats (CRISPR)-Cas13a, we firstly create an extraction-free one-pot immuno-RPA-CRISPR (opiCRISPR) for the direct and extremely sensitive detection of EVs proteins. The EVs protein-targeted detection probe is amplified by RPA to generate a long repetitive sequence containing multiple CRISPR RNA (crRNA) targeting barcodes, and the signal is further amplified by the CRISPR-Cas13a side-chain cleavage activity to generate a fluorescent signal. The results show that circulating extracellular vesicle GPC3 (eGPC3) levels are a reliable marker for GPC3 expression in tumor, opening up new avenues for tumor diagnosis. We created an eGPC3 assay based on the CRISPR-Cas13a system, and successfully study the significance of extracellular vesicle GPC3 markers in hepatocellular carcinoma. [Display omitted] • Sulfo-SMCC linking antibodies to sequences for isothermal amplification. • A highly sensitive method to identify proteins on extracellular vesicle membranes. • Glypican-3 on extracellular vesicle has been validated as an human hepatocellular carcinoma (HCC) diagnostic marker. • The entire reaction occurs at 37 °C and is very fast. [ABSTRACT FROM AUTHOR]