用于诱导纳米金快速聚集比色传感的DNA染料筛选  

Screening of DNA Dyes for Colorimetric Sensing Via Rapidly Inducing Gold Nanoparticles Aggregation

作　　者：叶子熠 刘霜 张信凤[1] YE Zi-yi;LIU Shuang;ZHANG Xin-feng(College of Materials and Chemistry&Chemical Engineering,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]成都理工大学材料与化学化工学院,四川成都610059

出　　处：《光谱学与光谱分析》2023年第9期2805-2810,共6页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(21475013),四川省科技厅应用基础项目(2018JY4066)资助。

摘　　要：近年来,金纳米粒子(AuNPs)因其极高的消光系数以及距离依赖性颜色而被广泛用于比色传感器的开发利用。常见的盐诱导AuNPs聚集通过电荷屏蔽的方式进行,聚集过程易受到干扰,聚集后颜色往往不稳定,而DNA染料通过电荷中和的方式实现AuNPs聚集,该方法具有用量少,聚集速度快,并且稳定性好的优势,因此对常见DNA染料进行筛选十分必要。系统筛选了8种常见DNA染料包括EB、AO、TO、SG、PG、TOTO^(-1)、TOTO-3和YOYO用于诱导AuNPs的快速聚集。实验发现诱导AuNPs团聚的染料用量在0.18~2.6μmol·L^(-1)之间,相比NaCl和Cys用量分别为60和20 mmol·L^(-1)的传统诱导聚集方法用量仅为万分之一。通过考察DNA染料诱导AuNPs聚集的“IC 50”值(即诱导剂使AuNPs聚集的最大吸光度变化(A 680/A 520)的50%的浓度)评价聚集效率,在筛选的8种DNA染料中,SG、PG、TOTO^(-1)、TOTO-3和YOYO分子的“IC 50”值在0.12~0.30μmol·L^(-1)之间,相对较小,诱导AuNPs聚集效率高。由于带正电的N原子数量对AuNPs的聚集有关键性的作用,即带正电的N原子数量越多,中和AuNPs时的用量越少。通过Marvin View中microspecies(微观结构式)和microspecies distribution(微观结构式分布)算出了具体带正电的N原子个数,结果表明,在pH=7条件下,SG、PG、TOTO^(-1)、TOTO-3和YOYO分子带正电荷的N原子较多,因此上述染料诱导AuNPs聚集效率高。通过乔布曲线(Job)计算出双链DNA(dsDNA)碱基对与DNA染料的结合比,结果表明相同条件下,筛选的8种DNA染料与dsDNA碱基对的结合比相差不大。结合实验拟合曲线计算出dsDNA与DNA染料的结合常数,计算表明SG,YOYO,TOTO-3,PG与dsDNA的结合常数较大,在2.75×109~3.12×1010 L·mol^(-1)之间,与DNA结合能力较强。综合考虑SG、PG、YOYO、TOTO-3等染料在快速诱导AuNPs聚集及比色传感方面效果较好。In recent years,gold nanoparticles(AuNPs)have been widely used in developing and utilising colorimetric sensors due to their extremely high extinction coefficient and distance-dependent color.Common salt-induced AuNP aggregation is carried out using charge shielding,the aggregation process is easily disturbed,and the color is often unstable after aggregation.DNA dyes achieve AuNPs aggregation by charge neutralization,which has the advantages of less dosage and faster aggregation speed.Fast and stable.Therefore,it is necessary to screen for common DNA dyes.In this paper,eight common DNA dyes,including EB,AO,TO,SG,PG,TOTO^(-1),TOTO-3 and YOYO,were systematically screened for inducing the rapid aggregation of AuNPs.Experiments found that the amount of dye to induce AuNPs agglomeration was between 0.18 and 2.6μmol·L^(-1),about 10000 times lower than the traditional method of inducing aggregation with NaCl and Cys dosages of 60 mmol·L^(-1)and 20 mmol·L^(-1),respectively.In addition,the aggregation efficiency was evaluated by examining the“IC 50”value of DNA dye-induced AuNPs aggregation(that is,the concentration of 50%of the maximum absorbance change(A 680/A 520)of AuNPs aggregation induced by the inducer).Among the eight DNA dyes screened,SG The“IC 50”values of,PG,TOTO^(-1),TOTO-3 and YOYO molecules were between 0.12 and 0.30μmol·L^(-1),which were relatively small,and the aggregation efficiency of AuNPs was high.Since the number of positively charged N atoms plays a key role in the aggregation of AuNPs,the more positively charged N atoms,the less the amount of neutralizing AuNPs.The number of positively charged N atoms was calculated through the microspecies and microspecies distribution in Marvin View.The results show that pH=7,SG,PG,TOTO^(-1),TOTO-3,And YOYO molecules have more positively charged N atoms,so the above dye-induced AuNPs aggregation efficiency is high.At the same time,the binding ratio of double-stranded DNA(dsDNA)base pairs to DNA dyes was calculated by the Job curve.The results showed

关 键 词：DNA染料 纳米金 结合常数 传感 

分 类 号：O657.3[理学—分析化学]