A Highly Sensitive and Selective Competition Assay for the Detection of Cysteine Using Mercury-Specific DNA, Hg2+ and Sybr Green I

Sensors

关键词: cysteine;    competition assay;    mercury-specific DNA;    Hg2+;    Sybr Green I;   

DOI  :  10.3390/s111110187

来源: DOAJ

【 摘 要 】

We here report a rapid, sensitive, selective and label-free fluorescence detection method for cysteine (Cys). The conformation of mercury-specific DNA (MSD) changes from a random coil form to a hairpin structure in the presence of Hg2+ due to the formation of a thymine-Hg2+-thymine (T-Hg2+-T) complex. Cys can selectively coordinate with Hg2+ and extract it from the thymine-Hg2+-thymine complex. The hairpin structure dehybridizes and the fluorescence intensity of Sybr Green I (SG) decreases upon addition of Cys because SG efficiently discriminates mercury-specific DNA and mercury-specific DNA/Hg2+ complex. The detection can be finished within 5 min with high sensitivity and selectivity. In addition, we can obtain variable dynamic ranges for Cys by changing the concentration of MSD/Hg2+.

【 授权许可】

Unknown