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Updated: May 19, 2026
An Anaerobic Biosensor Assay for the Detection of Mercury and Cadmium
Published on: December 17, 2018
[Detection of mercury (II) ions (Hg(2+)) in water by a nanobiosensor]
Wen-he Wu1, Xiao-lan Hong, Xu-wu Xiang
1Wenzhou Medical College, Zhejiang Provincial Key Laboratory of Medical Genefics, Wenzhou, Zhejiang, China.
Objective:
To develop a nanobiosensor for rapid colorimetric detecting Mercury (II) Ions (Hg(2+)) in water by mercury-specific oligonucleotides (MSOs) probe and gold nanoparticles.
Methods:
The nanobiosensor was assembled by adsorbing the optimized MSOs on the surface of gold nanoparticles. A direct colorimetric probe of Hg(2+) which relied on the T-T mismatches in DNA duplexes was used to selectively and strongly capture Hg(2+). Hg(2+) induces the aggregation of gold nanoparticles with appropriate amount of salts, resulting the color change (red to blue).
Results:
The diameter and concentration of the gold nanoparticle preparation were 15 nm and 2.97 nmol/L, respectively. Truncated MSOs (9 bp) showed the similar Hg(2+)-binding activity. The optimum concentration of the NaNO3 solution was 0.5 mol/L. The nanobiosensor could detect Hg(2+)in a range of 10 ∼ 1000 µmol/L within few minutes and the specificity was 100%.
Conclusion:
A new nanobiosensor is developed successfully for rapid colorimetric detecting Hg(2+) in water, avoiding either MSOs labeling or gold nanoparticles modification. This technique is simple, convenient and rapid detecting method with high sensitivity and specificity.
