Department of Rehabilitation Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, People's Republic of China. The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China. Bioinspired Engineering and Biomechanics Center (BEBC), Xian Jiaotong University, Xian 710049, People's Republic of China.
Nanotechnology. 2020 Mar 20;31(23):235501. doi: 10.1088/1361-6528/ab776d. Epub 2020 Feb 18.
The fluorescence resonance energy transfer (FRET)-based diagnosis method has been widely used in fast and accurate diagnosis. However, the traditional FRET-based diagnosis method is unable to detect long-chain DNA sequences, due to the limitation of the distance between the donor and acceptor, while the long-chain DNA sequence enables higher selectivity and is quite important for confirming many major diseases. Therefore, it is urgently needed to develop an efficient FRET system for long-chain DNA detection. Herein a 'head-to-tail' structure was developed using NaYF:Yb,Er nanoparticles as the energy donor and gold nanoparticles (AuNPs) as the acceptor to detect long-chain oligonucleotides sequences (i.e., HIV DNA, 52 bp). We modified NaYF:Yb,Er nanoparticles with carboxylic acid groups by using poly(acrylic acid) to enhance its hydrophilic and then covalently attached 5 'end of capture oligonucleotides strand to the surface of the particles. In the presence of target HIV DNA, gold nanoparticles with reported DNA were brought close to NaYF:Yb,Er nanoparticles upon 'head-to-tail' sandwich hybridization with target HIV DNA, resulting in an efficient FRET. Moreover, benefited from both photostable nanoparticles of UCNPs and AuNPs, the photobleaching issue has also been settled down. This developed method possesses high selectivity, high sensitivity, and reached a nanomolar limitation level. To our knowledge, it is the first time to report a 'head-to-tail' structure FRET system for detecting long-chain DNA sequences.
荧光共振能量转移（FRET）诊断方法已被广泛应用于快速准确的诊断。然而，传统的基于 FRET 的诊断方法由于供体和受体之间的距离限制，无法检测长链 DNA 序列，而长链 DNA 序列具有更高的选择性，对于确认许多重大疾病非常重要。因此，迫切需要开发一种用于长链 DNA 检测的高效 FRET 系统。在此，我们使用 NaYF:Yb,Er 纳米粒子作为能量供体和金纳米粒子（AuNPs）作为受体，开发了一种“头到尾”结构，用于检测长链寡核苷酸序列（即 HIV DNA，52 bp）。我们通过使用聚丙烯酸对 NaYF:Yb,Er 纳米粒子进行羧基化修饰，增强其亲水性，然后将捕获寡核苷酸链的 5'端通过共价键连接到粒子表面。在存在靶 HIV DNA 的情况下，与靶 HIV DNA 进行“头到尾”三明治杂交后，带有报告 DNA 的金纳米粒子会被拉近到 NaYF:Yb,Er 纳米粒子附近，从而实现有效的 FRET。此外，得益于上转换纳米粒子（UCNPs）和金纳米粒子的光稳定性，也解决了光漂白问题。该方法具有高选择性、高灵敏度，检测限达到纳摩尔水平。据我们所知，这是首次报道用于检测长链 DNA 序列的“头到尾”结构 FRET 系统。
