College of Information Science and Engineering, Northeastern University, Shenyang 110819, China.
College of Information Science and Engineering, Northeastern University, Shenyang 110819, China; Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology, Qinhuangdao 066004, China; State Key Laboratory of Synthetical Automation for Process Industries, Shenyang 110819, China.
Talanta. 2022 Sep 1;247:123599. doi: 10.1016/j.talanta.2022.123599. Epub 2022 May 28.
An optical fiber SPR biosensor based on multimode fiber (MMF)- hollow core fiber (HCF)-MMF is proposed and experimentally confirmed for in situ DNA hybridization analysis. In order to improve the sensitivity of DNA hybridization detection, a sandwich model based on gold nanoparticles (AuNPs) amplification is proposed. In this model, the probe DNA (pDNA) is first modified on the optical fiber sensing area by covalent bonding, and then the biotinylated target DNA (tDNA) is modified on the AuNPs by the high affinity between biotin and streptavidin. Finally, the tDNA on the surface of the AuNPs specifically hybridizes with the pDNA on the optical fiber to form a sandwich model. The near field coupling enhancement between AuNPs and gold film and the high mass ratio of AuNPs give high sensitivity to DNA hybridization detection. Experimental results show that the sandwich-type fiber SPR sensor has a log-linear response in the DNA concentration range of 1 pM-10 nM, and the sensitivity and detection limit are 4.04 nm/log(μM) and 1pM, respectively. This is 1.44 times more sensitive than that without sandwich assay. In addition, the DNA sensor has good specificity and stability, which foreshadows its great application potential in the fields of disease diagnosis, microbial detection and environmental science.
一种基于多模光纤（MMF）-空心光纤（HCF）-MMF 的光纤 SPR 生物传感器被提出并通过实验证实可用于原位 DNA 杂交分析。为了提高 DNA 杂交检测的灵敏度，提出了一种基于金纳米粒子（AuNPs）放大的三明治模型。在该模型中，通过共价键将探针 DNA（pDNA）首先修饰在光纤传感区域上，然后通过生物素和链霉亲和素之间的高亲和力将生物素化的靶 DNA（tDNA）修饰在 AuNPs 上。最后，AuNPs 表面上的 tDNA 与光纤上的 pDNA 特异性杂交形成三明治结构。AuNPs 和金膜之间的近场耦合增强以及 AuNPs 的高质量比赋予了 DNA 杂交检测的高灵敏度。实验结果表明，三明治型光纤 SPR 传感器在 1 pM-10 nM 的 DNA 浓度范围内具有对数线性响应，灵敏度和检测限分别为 4.04nm/log(μM)和 1pM，比没有三明治检测时提高了 1.44 倍。此外，DNA 传感器具有良好的特异性和稳定性，预示着其在疾病诊断、微生物检测和环境科学等领域具有巨大的应用潜力。
