Key Laboratory of Chemo/Biosensing, Anhui Province, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, 241000, China.
Analyst. 2011 Oct 7;136(19):3973-80. doi: 10.1039/c1an15287d. Epub 2011 Aug 16.
A novel and efficient method to evaluate the DNA hybridization based on a fluorescence resonance energy transfer (FRET) system, with fluorescein isothiocyanate (FITC)-doped fluorescent silica nanoparticles (SiNPs) as donor and gold nanoparticles (AuNPs) as acceptor, has been reported. The strategy for specific DNA sequence detecting is based on DNA hybridization event, which is detected via excitation of SiNPs-oligonucleotide conjugates and energy transfer to AuNPs-oligonucleotide conjugates. The proximity required for FRET arises when the SiNPs-oligonucleotide conjugates hybridize with partly complementary AuNPs-oligonucleotide conjugates, resulting in the fluorescence quenching of donors, SiNPs-oligonucleotide conjugates, and the formation of a weakly fluorescent complex, SiNPs-dsDNA-AuNPs. Upon the addition of the target DNA sequence to SiNPs-dsDNA-AuNPs complex, the fluorescence restores (turn-on). Based on the restored fluorescence, a homogeneous assay for the target DNA is proposed. Our results have shown that the linear range for target DNA detection is 0-35.0 nM with a detection limit (3σ) of 3.0 picomole. Compared with FITC-dsDNA-AuNPs probe system, the sensitivity of the proposed probe system for target DNA detection is increased by a factor of 3.4-fold.
一种新颖、高效的荧光共振能量转移（FRET）体系用于评估 DNA 杂交的方法被报道。该方法以异硫氰酸荧光素（FITC）掺杂荧光硅纳米粒子（SiNPs）作为供体，金纳米粒子（AuNPs）作为受体。基于特定 DNA 序列检测的策略是基于 DNA 杂交事件，通过激发 SiNPs-寡核苷酸偶联物并将能量转移到 AuNPs-寡核苷酸偶联物来检测。当 SiNPs-寡核苷酸偶联物与部分互补的 AuNPs-寡核苷酸偶联物杂交时，就会产生 FRET 所需的接近度，从而导致供体 SiNPs-寡核苷酸偶联物的荧光猝灭，并形成弱荧光复合物 SiNPs-dsDNA-AuNPs。当目标 DNA 序列加入到 SiNPs-dsDNA-AuNPs 复合物中时，荧光恢复（开启）。基于恢复的荧光，提出了一种用于目标 DNA 的均相测定方法。我们的结果表明，目标 DNA 检测的线性范围为 0-35.0 nM，检测限（3σ）为 3.0 皮摩尔。与 FITC-dsDNA-AuNPs 探针系统相比，该探针系统用于目标 DNA 检测的灵敏度提高了 3.4 倍。
