聚集诱导发光分子/适配体/外切酶Ⅰ体系对可卡因的检测

Detection of Cocaine Based on the System of AIEgen,Aptamer and Exonuclease Ⅰ

目前非法药物的滥用已经成为全球性的公共安全卫生问题之一[1~3].其中可卡因作为一种全球禁用的非法药物,长期滥用会对人体造成许多不良的影响,如精神疾病、失眠、抑郁和暴力倾向等,甚至威胁生命,同时,吸食可卡因还会导致出现各种社会问题[4,5].因此实现对可卡因的快速检测成为打击毒品犯罪、维护社会稳定的关键.目前对于可卡因的检测主要采用气相色谱/质谱(GC/MS)和液相色谱/质谱(LC/MS)等大型仪器.虽然能够实现对可卡因检测,但大多需要专业人员操作且耗时较长,因此开发一种简便、高效且可靠的可卡因检测方法成为研究的热点[6~8].其中,基于荧光探针的检测手段由于具有高效、灵敏及便捷等优势而备受关注,但传统的荧光探针面临聚集导致发光猝灭(ACQ)的难题[9,10],即这类分子在溶液中发光非常强,一旦聚集或在固体中发光显著减弱,非常不利于实际应用.

A new system for detection of cocaine was designed based on an AIEgen of TPE-TTA,anticocaine aptamer and exonucleaseⅠ(ExoⅠ).The ExoⅠcan specifically cleave the phosphodiester bonds of nucleotides in nucleic acids either from the ends or interior of single stranded DNA(ssDNA).Meanwhile,the cocaine can combine with anticocaine aptamer and switch its configuration to Y-shaped double stranded DNAs(dsDNA)that prevent the aptamer degradation in the presence of ExoⅠ.When cationic 4,4′,4″,4″′-{[ethene-1,1,2,2-tetrayltetrakis(benzene-4,1-diyl)]tetrakis(oxy)}-tetrakis(N,N,N-triethylbutan-1-aminium)bromide(TPE-TTA)was added to the Tris-HCl solution,it can combine with aptamer and the fluore-scence was turned on.The experiment conditions,including the amount of ExoⅠ,incubation time of the ExoⅠwith anticocaine aptamer,incubation temperature and time of anticocaine aptamer with cocaine were systematically investigated and the optimal conditions were obtained.With different concentrations of cocaine,the experimental results showed that the fluorescence intensity was progressively enhanced.The limit of detection(LOD)of 0.66μmol/L was deduced.Moreover,the developed method also was used to determine cocaine in real urine samples,and the LOD can reach as low as 1.0μmol/L.This work provides a new method for cocaine detection,which is promising for practical application.