基于适配体的条带生物传感器中 DNA 功能化金纳米粒子探针的可视化检测卡那霉素

Visual detection of kanamycin with DNA-functionalized gold nanoparticles probe in aptamer-based strip biosensor.

机构信息

The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.

出版信息

Anal Biochem. 2019 Dec 15;587:113432. doi: 10.1016/j.ab.2019.113432. Epub 2019 Sep 12.

DOI:10.1016/j.ab.2019.113432

PMID:31521669

Abstract

Kanamycin has been widely used to treat human and animal diseases. The excessive use of kanamycin causes its accumulation in animal-derived foods, and eventually threats human health. In the present study, we develop a lateral flow strip biosensor for fast and sensitive detection of kanamycin. The strip biosensor combines the easy separation of magnetic microspheres (MMS) with target-mediated chain displacement of single-stranded DNA and the capture of the visible DNA-functionalized gold nanoparticles (AuNPs) probe. The presence of kanamycin can competitively bind to the aptamer and release cDNA to the supernatant. The concentration of free cDNA, which is the direct target of the strip, is proportional to the concentration of kanamycin. The capture of DNA-functionalized AuNPs on the test zone of the strip through cDNA-induced hybridization provides a visual detection signal. The assay can be completed within 20 min. The visual detection limit by naked eyes of the strip is 50 nM. A linear detection range of 5-500 nM is derived for quantitative determination, with the detection limit of 4.96 nM (S/N = 3). This lateral flow strip biosensor can quickly and sensitively detect kanamycin in different food samples, which holds great application potential in medicine and daily life.

摘要

卡那霉素被广泛用于治疗人类和动物疾病。卡那霉素的过量使用导致其在动物源性食品中的积累，最终威胁到人类健康。在本研究中，我们开发了一种用于快速灵敏检测卡那霉素的侧向流动条生物传感器。该条生物传感器将磁珠（MMS）的易于分离与单链 DNA 的目标介导链置换以及可见的 DNA 功能化金纳米颗粒（AuNPs）探针的捕获相结合。卡那霉素的存在可以竞争性地与适体结合，并将 cDNA 释放到上清液中。游离 cDNA 的浓度与卡那霉素的浓度成正比，cDNA 是条带的直接靶标。通过 cDNA 诱导的杂交，在条带的检测区捕获 DNA 功能化的 AuNPs 提供了可视化的检测信号。该测定可以在 20 分钟内完成。通过肉眼观察，条带的可视化检测限为 50 nM。定量测定得到 5-500 nM 的线性检测范围，检测限为 4.96 nM（S/N = 3）。这种侧向流动条生物传感器可以快速灵敏地检测不同食品样品中的卡那霉素，在医学和日常生活中具有很大的应用潜力。