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Updated: Mar 22, 2026

Split Hybridization Probe Utilizing a DNA Fluorescent Light-up Aptamer as a Signal Reporter for Sequence-Specific Nucleic Acid Analysis
Published on: July 8, 2025
Terminal protection of a small molecule-linked loop DNA probe for turn-on label-free fluorescence detection of
Xuexu Chen1, Chunshui Lin2, Yiying Chen1
1Department of Chemistry and the MOE Key Laboratory of Spectrochemical Analysis & Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
Abstract:
A novel label-free turn-on fluorescence biosensor for the determination of streptavidin (SA) was proposed. Using terminal protection of small molecule-linked DNA chimeras, which can protect DNA from degradation by various exonucleases when the small molecule moieties are bound to their protein target, we designed a loop probe, where the 3'-end was modified with biotin to resist digestion by exonucleases in the presence of target SA. Coupled with an intercalating dye, SYBR Green I, strong enhancement of the fluorescence signals was obtained compared with that in the absence of SA. A linear correlation equation was obtained for SA from 0 to 200nM with a limit detection of 0.4nM. This strategy holds great promise for practical applications with good specificity and sensitivity.
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