以羧基碳纳米颗粒为淬灭剂的 “turn-on” 碳点标记生物荧光传感器的构建及应用...

生物荧光传感器因易操作、信号稳定、灵敏度高及选择性好等特点，已成为生物医药分析领域的重要工具。新型纳米材料碳点具有优良的光学特性，易溶于水，制备简单且无毒，作为荧光标记物，与适配体偶联形成的turn-on生物荧光传感器，可以高灵敏、高选择地检测生物分子。目前，该传感体系的淬灭剂多为碳纳米管、石墨烯等，由于这些材料水溶性较差，测定时不易分散在水相而导致操作困难，严重影响测定的准确度。近来报道羧基碳纳米颗粒水相分散性好，可淬灭荧光素的荧光，但未见作为淬灭剂，用于碳点标记的荧光传感器。本项目拟以羧基碳纳米颗粒为淬灭剂，将碳点标记在凝血酶、多巴胺及甲胎蛋白等生物分子的适配体上，构建turn-on生物荧光传感体系。利用该传感平台，通过分子识别原理，建立一系列高灵敏和高选择性的生物传感新方法。旨在为生物医药等领域提供非常有效的、新的分析手段和技术支撑，改进现有方法操作困难、检测准确性差及费用高等缺点。

Fluorescent biosensors have become very important tools in the field of biomedical analysis because of their easy operation, signal stability, high sensitivity and good selectivity. Carbon dots (CDs) is of high fluorescence intensity, water soluble, easy synthesis and nontoxic. Turn-on type fluorescent biosensors produced by coupling CDs with aptamer can detect biomolecules with high sensitivity and selectivity. However, carbon nanotubes, graphene, etc., commonly used as the quenchers in this type of biosensors, have the defect of poor solubility. These quenchers make turn-on type CDs marked fluorescent biosensors troublesome operating which introduces poor measurement accuracy. In very recent years there have been a few reports about carboxylic carbon nanoparticles (cCNPs) which have good dispersion in water, non-toxic and cheap, and can quench the fluorescent of a fluorescein. However, to the best of our knowledge, cCNPs have been not used in turn-on type CDs marked fluorescent biosensors. The present project plans to use cCNPs as a quencher and CDs as a fluorescent marker linked with aptamers of thrombin, dopamine, alpha fetoprotein, respectively, to form turn-on type fluorescent biosensors. Based on the molecular recognition principles, a series of new biosensing method with high sensitivity and high selectivity properties for some biomolecules will be established by using this fluorescent sensing platform. The aims are to provide very effective, new analysis methods and technical support for biomedical research fields, overcoming the defects of the existing methods, such as troubled operating, inaccuracy and high costs.