分析化学2026，Vol.54Issue(2)：232-240,中插16-中插17,11.DOI:10.19756/j.issn.0253-3820.251275
基于五支DNA纳米结构组装银纳米多簇的比率荧光传感方法检测冠状病毒DNA标志物
Ratiometric Fluorescence Biosensing of Multi-Silver Nanoclusters Hosted in Five-Branched DNA Nanostructure for Detection of Coronavirus DNA Biomarker
摘要
Abstract
Exploring the spectral features of multi-Ag nanoclusters(5rAgNC)populated in five-branched DNA nanostructures(fbDNS)might be very fascinating for label-free ratiometric fluorescence biosensing.Herein,the complementary hybridization was used to self-assemble fbDNS for in situ synthesizing red multi-Ag nanoclusters(5rAgNC).By using fluorescent intensity ratio of 5rAgNC over green Ag nanocluster(gAgNC)as the signal,highly sensitive analytical method for detecting short-stranded DNA biomarker(I*,25-nt)related to severe acute respiratory syndrome coronavirus type 2(SARS-CoV-2)was developed.The specific recognition of I*enabled the sequential dissociation and hybridization for assembling rigid fbDNS within five functional hairpins,thereby displacing I* for repetitive recycling,and their five arms all tethered the same sticking toeholds.The sticking toeholds complement was encoded in the loop of dual-template hairpin(dtH)being able to host gAgNC and 5rAgNC between two conformations.The specific binding made dtH lose its hairpin structure to guide the immobilization in the sticking arms of fbDNS.Resultantly,the structure reconstruction of immobilized dtH released stem segment to connect 5'-toehold bases for 5rAgNC clustering.In a typical reaction route,the rising of I* concentration led to an opposite change with gradual increasing of fluorescent intensity of 5rAgNC and decreasing of fluorescent intensity ofgAgNC.Based on this,a sensitive detection method for I*concentration was fabricated.In the concentration range of 5 pmol/L–10 nmol/L,the fluorescence intensity ratio of 5rAgNC togAgNC had a linear relationship with logarithm of I*concentration.The limit of detection(LOD,3σ)for I*was 2.9 pmol/L.This method exhibited good specificity for I*.The strategy based on recycled amplification of I*and cooperative emission of multi-nanoclusters displayed superior advantages such as easy operation,fast reaction kinetics,efficient conversion,and improved analysis precision.关键词
比率荧光生物传感/五支DNA纳米结构/双色银纳米簇/协同增强/目标物循环放大/DNA/标志物Key words
Ratiometric fluorescence biosensing/Five-branched DNA nanostructure/Bicolor silver nanoclusters/Cooperative enhancement/Target recycling amplification/DNA/Biomarker引用本文复制引用
张宇晴,邓惠林,郑欣娅,许文菊..基于五支DNA纳米结构组装银纳米多簇的比率荧光传感方法检测冠状病毒DNA标志物[J].分析化学,2026,54(2):232-240,中插16-中插17,11.基金项目
国家自然科学基金项目(No.22476162)和重庆市自然科学基金项目(No.CSTB2024NSCQ-MSX0357)资助. Supported by the National Natural Science Foundation of China(No.22476162)and the Natural Science Foundation of Chongqing(No.CSTB2024NSCQ-MSX0357). （No.22476162）
