Thymine-Hg~(2+)-Thymine Structure-based Detection of Hg~(2+) Enhanced by Gold Nanoparticle
A simple and sensitive method was developed for the detection of mercury ions with quartz crystal microbalance(QCM),based on the specific thymine(T)-Hg2+-T structure and gold nanoparticles.The gold nanoparticles were prepared by the citrate reduction method.In a self-assembled way,the particle surface was modified with the probe oligonucleotides which were partially replaced by 6-Mercaptohexan-1-ol to reduce the steric hindrance of hybridization.The sensitivity was optimized by the oligonucleotide with a strand length of 9bp and a T number of 7.The linear range was 5.0-100 nmol/L with a detection limit of 2.0 nmol/L.And Ca2+,Mg2+ and other metal ions had no significant interferences.This method was successfully applied for the detection of Hg2+in environmental water samples,with RSD less than 2.9% and recoveries of 97.3%-101.2%.