基于DNA模板合成的银簇建立“点亮型”荧光法检测卡那霉素  

Detection of Kanamycin by a “Light-up” Fluorescence Method Based on DNA Template Synthesized Silver Clusters

作　　者：林碧霞[1] 蒙佩怡 陈梦玲 吴峻宇 冷江东 黄月梅 杨诗意 俞英[1] LIN Bi-xia;MENG Pei-yi;CHEN Meng-ling;WU Jun-yu;LENG Jiang-dong;HUANG Yue-mei;YANG Shi-yi;YU Ying(Guangzhou Key Laboratory of Analytical Chemistry for Biomedicine,South China Normal University,Guangzhou 510006,China)

机构地区：[1]华南师范大学广州市生物医药分析化学重点实验室

出　　处：《分析测试学报》2019年第9期1051-1058,共8页Journal of Instrumental Analysis

基　　金：国家自然科学基金资助项目(21575043,21275056);广州市创新平台开放共享专项项目(15180001)

摘　　要：以DNA为模板合成弱荧光的银纳米簇。利用DNA模板中的适配体序列识别目标卡那霉素后,形成发夹结构使适配体序列上的G碱基和C碱基靠近银簇,导致银簇荧光增强。同时,DNA二级结构的改变使银纳米粒子形成小的银纳米簇也促使银簇的荧光增强。据此建立“点亮型”荧光法对卡那霉素进行定量分析。银簇荧光增强比值与卡那霉素浓度在0.075~8.0μmol/L范围内呈线性关系,线性方程为F/F0=0.616 8C+0.927 6,检出限为36 nmol/L。卡那霉素在牛奶和蜂蜜样品中的回收率为92.4%~112%。此外,随着卡那霉素加入浓度的增加,银簇的橙色荧光逐渐加深,根据荧光颜色深度可对卡那霉素进行可视化半定量检测。该方法具有灵敏度高、选择性好的优点,可用于复杂食品样品中痕量卡那霉素的定量检测。A“light-up”fluorescence method was developed for the quantitative analysis of kanamycin based on DNA template synthesized silver nanoclusters(AgNCs).The silver nanoclusters with weak fluorescence were synthesized with DNA as template.A hairpin structure was formed to make the G and C bases in the aptamer sequence of DNA template close to the silver nanoclusters when the target kanamycin was identified by the aptamer sequence,which could result in the increase of fluorescence of silver clusters.Meanwhile,the change of secondary structure caused the silver nanoparticles to transform into smaller silver nanoclusters,which also enhanced the fluorescence of silver clusters.A“light-up”fluorescence method was established based on this mechanism.There was a linear relationship between fluorescence intensity ratio of silver nanoclusters and kanamycin in the concentration range of 0.075-8.0μmol/L with a calibration curve of F/F0=0.616 8C+0.927 6,and a detection limit of 36 nmol/L.The spiked recoveries for kanamycin in milk and honey samples ranged from 92.4%to 112%.In addition,with the increase of kanamycin concentration,the orange fluorescence of silver nanoclusters was deepened gradually,which could be used for the visual semi-quantitative detection of kanamycin.With good sensitivity and selectivity,the method could be used in the quantitative determination of trace kanamycin in complex food samples.

关 键 词：DNA模板 银纳米簇(AgNCs) 卡那霉素 可视化检测 

分 类 号：O657.3[理学—分析化学] TQ460.72[理学—化学]