羧甲基壳聚糖-分子信标-金纳米生物传感器检测鼠伤寒沙门氏菌

Detection on Salmonella typhimurium by Carboxymethyl Chitosan-Molecular Beacon-Gold Nano Biosensor

基于传统的沙门氏菌检测方法检测周期长、效率不高等缺陷,本研究通过合成一种羧甲基壳聚糖-分子信标-金纳米材料,采用一种新的基于分子信标共价功能化的壳聚糖技术和金纳米团聚比色的方法对含SSeC基因的鼠伤寒沙门氏菌进行检测。在羧甲基壳聚糖上交联环状结构的适配体,当加入靶标之后,由于靶标与环状结构适配体结合导致分子信标刚性结构崩解,插入茎状结构中的金纳米颗粒(GNRs)释放出来,当在溶液中加入一定量的NaCl溶液后,金纳米颗粒会发生团聚,根据聚合度的不同,产生相应颜色变化,从而实现对含SSeC基因的鼠伤寒沙门氏菌的快速检测,结果表明:通过检测金纳米颗粒发生的显色反应的吸光度可以实现对含有SSeC基因的鼠伤寒沙门氏菌进行快速检测,并且这种方法具有较高的特异性和灵敏度。在此检测体系中,靶标浓度和显色反应的吸光度值在0.05~0.5μmol/L内具有良好的线性关系,并且对于靶标DNA的检测下限为50nmol/L。

Based on the defects of traditional Salmonella detection methods such as long-term,low-efficiency,a novel carboxymethyl chitosan-molecular beacon-gold nanomaterial was synthesized.Salmonella typhimurium containing SSeC gene was detected by a novel chitosan technique based on covalent functionalization of molecular beacons and gold nano-agglomeration colorimetric method.The aptamer of the cyclic structure was cross-linked on carboxymethyl chitosan.After the target was added,the molecular beacon rigid structure disintegrates due to the binding of the target to the cyclic aptamer,and the gold nanoparticle inserted into the stem structure is inserted.The particles(GNRs)were released.When a certain amount of NaCl solution was added to the solution,the gold nanoparticles would agglomerate,and corresponding color changes would be produced according to the degree of polymerization,thereby realizing rapid detection of Salmonella typhimurium containing SSeC gene.The experimental results showed that the rapid detection of Salmonella typhimurium containing SSeC gene would be achieved by detecting the absorbance of the color reaction of gold nanoparticles,and this method had high specificity and sensitivity.In this detection system,the target concentration and the absorbance value of the color reaction had a good linear relationship in the range of 0.05μmol/L to 0.5μmol/L,and the detection limit for the target DNA was 50 nmol/L.