Highly sensitive colorimetric sensor for Hg(2+) detection based on cationic polymer/DNA interaction.
The detection of ultralow concentrations of mercury is a currently significant challenge. Here, a novel strategy is proposed: the colorimetric detection of Hg(2+) based on the aggregation of gold nanoparticles (AuNPs) driven by a cationic polymer. In this three-component system, DNA combines electrostatically with phthalic diglycol diacrylate (PDDA) in a solution of AuNPs. In the presence of Hg(2+), thymine (T)-Hg(2+)-T induced hairpin turns are formed in the DNA strands, which then do not interact with PDDA, enabling the freed PDDA to subsequently facilitate aggregation of the AuNPs. Thus, according to the change in color from wine-red to blue-purple upon AuNPs aggregation, a colorimetric sensor is established to detect Hg(2+). Under optimal conditions, the color change is clearly seen with the naked eye. A linear range of 0.25-500nM was obtained by absorption spectroscopy with a detection limit of approximately 0.15nM. Additionally, the proposed method shows high selectivity toward Hg(2+) in the presence of other heavy metal ions. Real sample analysis was evaluated with the use of lake water and the results suggest good potential for practical application.
School of Biotechnology and Food Engineering, Changshu Institute of Technology, Changshu, Jiangsu 215500, China.
Yingyue
Y
Zhu
School of Biotechnology and Food Engineering, Changshu Institute of Technology, Changshu, Jiangsu 215500, China; School of Chemical Engineering & Technology, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China.
Yilin
Y
Cai
School of Biotechnology and Food Engineering, Changshu Institute of Technology, Changshu, Jiangsu 215500, China.
Yibo
Y
Zhu
School of Biotechnology and Food Engineering, Changshu Institute of Technology, Changshu, Jiangsu 215500, China.
Lixue
L
Zheng
School of Biotechnology and Food Engineering, Changshu Institute of Technology, Changshu, Jiangsu 215500, China.
Jianying
J
Ding
School of Biotechnology and Food Engineering, Changshu Institute of Technology, Changshu, Jiangsu 215500, China.
Ying
Y
Quan
School of Biotechnology and Food Engineering, Changshu Institute of Technology, Changshu, Jiangsu 215500, China.
Limei
L
Wang
School of Biotechnology and Food Engineering, Changshu Institute of Technology, Changshu, Jiangsu 215500, China. Electronic address: qbcslg@163.com.
Bin
B
Qi
D002412:Cations; D003124:Colorimetry / Q000295:instrumentation*; D004247:DNA / Q000737:chemistry*; D004784:Environmental Monitoring / Q000295:instrumentation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D011095:Polyethylenes / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
D002412:Cations; D011095:Polyethylenes; D011108:Polymers; D000644:Quaternary Ammonium Compounds; D014874:Water Pollutants, Chemical; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; D006046:Gold; D004247:DNA; D008628:Mercury
AuNPs aggregation; Colorimetric sensor; Mercury ion; T-Hg(2+)-T