One-pot synthesis of fluorescent oligonucleotide Ag nanoclusters for specific and sensitive detection of DNA

• Published in: Biosensors & bioelectronics 2011-01, Vol.26 (5), p.2431-2435
• Main Authors: Lan, Guo-Yu, Chen, Wei-Yu, Chang, Huan-Tsung
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biotechnology; DNA - analysis; DNA - genetics; DNA detection; DNA Mutational Analysis - instrumentation; Equipment Design; Equipment Failure Analysis; Fluorescent probes; Fundamental and applied biological sciences. Psychology; Hereditary tyrosinemia type I; In Situ Hybridization, Fluorescence - instrumentation; Nanoclusters; Nanostructures - chemistry; Oligonucleotides - chemistry; Polymorphism, Single Nucleotide - genetics; Silver - chemistry; SNPs; Solutions
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2010.10.026

In this study, we prepared fluorescent, functional oligonucleotide-stabilized silver nanoclusters (FFDNA-Ag NCs) through one-pot synthesis and then employed them as probes for single nucleotide polymorphisms (SNPs). The FFDNA-Ag NCs were obtained through the NaBH 4-mediated reduction of AgNO 3 in the presence of a DNA strand having the sequence 5′-C 12-CCAGATACTCACCGG-3′. The specific DNA scaffold combines a fluorescent base motif (C 12) and a specific sequence (CCAGATACTCACCGG) that recognizes a gene for fumarylacetoacetate hydrolase (FAH). The sensing mechanism of our new probe is based on the FFDNA-Ag NCs having different stabilities (fluorescence intensities) in solutions containing 150 mM NaCl in the absence and presence of perfect match DNA (DNA pmt). Under the optimal conditions (150 mM NaCl, 20 mM phosphate solution, pH 7.0), the fluorescence ratios of the FFDNA-Ag NC probes in the presence and absence of DNA pmt, plotted against the concentration of DNA pmt, was linear over the range 25–1000 nM ( R 2 = 0.98), with a limit of detection (S/N = 3) of 14 nM. This cost-effective and simple FFDNA-Ag NC probe is sensitive and selective for SNPs of a gene for FAH.