Electrochemical Biosensor Using DNA Embedded Phosphorothioate Modified RNA for Mercury Ion Determination

Area of Science:

• Environmental Science
• Analytical Chemistry
• Nanotechnology

Background:

• Mercury (Hg) contamination poses significant environmental and health risks.
• Accurate and rapid mercury detection methods are crucial for monitoring and mitigation.

Purpose of the Study:

• To develop a sensitive, label-free biosensor for detecting mercury(II) ions (Hg(II)).
• To utilize Hg(II)-induced RNA cleavage coupled with field-effect transistor technology.

Main Methods:

• A biosensor was constructed by linking Hg(II)-dependent phosphorothioate-modified RNA (Hg-DPR) to single-walled carbon nanotube field-effect transistors (SWNTs/FET).
• The sensor detects Hg(II) by measuring changes in SWNTs conductivity due to Hg(II)-induced cleavage of Hg-DPR.

Main Results:

• The Hg-DPR/SWNTs/FET biosensor achieved sensitive detection of Hg(II) down to 10 pM.
• Linear calibration curves were observed across different concentration ranges (50 pM–100 nM and 100 nM–10 μM).
• The biosensor demonstrated high sensitivity, portability, and cost-effectiveness.

Conclusions:

• The developed Hg-DPR/SWNTs/FET biosensor provides a promising platform for rapid and accurate Hg(II) detection.
• This technology offers a viable solution for environmental monitoring and public health surveillance of mercury contamination.