"Off-On"switching electrochemiluminescence biosensor for mercury(II) detection based on molecular recognition...

Area of Science:

• Analytical Chemistry
• Nanotechnology
• Biotechnology

Background:

• Mercury(II) poses significant environmental and health risks.
• Development of sensitive and selective biosensors for mercury detection is crucial.
• Electrogenerated chemiluminescence (ECL) offers advantages for biosensing applications.

Purpose of the Study:

• To develop a novel "off-On" electrogenerated chemiluminescence (ECL) biosensor for mercury(II) detection.
• To utilize molecular recognition technology for selective mercury(II) sensing.
• To achieve a low detection limit for mercury(II) ions.

Main Methods:

• Fabrication of an ECL substrate on a glass carbon electrode (GCE) using Ruthenium(II) tris-(bipyridine)/Cyclodextrins-Au nanoparticles/Nafion.
• Design and functionalization of a single hairpin DNA probe with a ferrocene tag for molecular recognition.
• Immobilization of the DNA probe onto the modified GCE via supramolecular noncovalent interaction.
• Monitoring ECL signal changes based on the formation of T-Hg(II)-T complexes.

Main Results:

• The biosensor exhibited an "off-On" ECL response, with ECL quenched in the absence of mercury(II).
• The presence of mercury(II) ions induced T-Hg(II)-T complex formation, leading to significant ECL recovery.
• The developed biosensor demonstrated high selectivity and sensitivity for mercury(II) detection.
• A low detection limit of 0.1 nM for mercury(II) was achieved.

Conclusions:

• A novel and effective "off-On" ECL biosensor for mercury(II) detection has been successfully developed.
• The biosensor leverages molecular recognition and ECL principles for sensitive and selective mercury(II) analysis.
• This platform offers a simple, rapid, and selective method for environmental and biological monitoring of mercury(II).