Recognition and quantification of oligonucleotide sequences play important roles in medical diagnosis. In this study, a new fluorescent oligonucleotide‐stabilized silver nanocluster beacon (NCB) probe was designed for sensitive detection of oligonucleotide sequence targets. This probe contained two tailored DNA strands. One strand was a signal probe strand containing a cytosine‐rich strand template for fluorescent silver nanocluster (Ag NC) synthesis and a detection sections at each end. The other strand was a fluorescence enhancing strand containing a guanine‐rich section for signal enhancement at one end and a linker section complementary to one end of the signal probe strand. After synthesis of the Ag NCs and hybridization of the two strands, the fluorescence intensity of the as‐prepared silver NCB was enhanced 200‐fold compared with the Ag NCs. Two NCBs were designed to detect two disease‐related oligonucleotide sequences, and results indicated that the two target oligonucleotide sequences in the range 50.0–600.0 and 50.0–200.0 nM could be linearly detected with detection limits of 20 and 25 nM, respectively. The developed fluorescence method using NCBs for oligonucleotide sequence detection was sensitive, facile and had potential for use in bioanalysis and diagnosis.

中文翻译：

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基于银纳米簇信标的荧光“关闭”的DNA生物测定。

寡核苷酸序列的识别和定量在医学诊断中起重要作用。在这项研究中，设计了一种新型的荧光寡核苷酸稳定化的银纳米簇信标（NCB）探针，用于灵敏地检测寡核苷酸序列靶标。该探针包含两条定制的DNA链。一条信号线是一条信号探针链，其中包含用于荧光银纳米簇（Ag NC）合成的富含胞嘧啶的链模板，并且在每个末端都有一个检测区域。另一条链是荧光增强链，在一端含有一个富含鸟嘌呤的区域，用于信号增强，另一个与信号探针链的一端互补。合成Ag NCs并杂交两条链后，与Ag NCs相比，制备的银NCB的荧光强度提高了200倍。设计了两个NCB来检测与疾病相关的两个寡核苷酸序列，结果表明，可以线性检测50.0–600.0和50.0–200.0 nM范围内的两个目标寡核苷酸序列，检测限分别为20和25 nM。使用NCBs进行寡核苷酸序列检测的已开发的荧光方法灵敏，易行，具有用于生物分析和诊断的潜力。