Highly Sensitive Aptasensor for Trace Arsenic(III) Detection Using DNAzyme as the Biocatalytic Amplifier

Area of Science:

• Analytical Chemistry
• Biotechnology
• Environmental Science

Background:

• Arsenic(III) (As³⁺) contamination poses significant health risks.
• Highly sensitive and selective detection methods for As³⁺ are crucial for environmental monitoring.
• Existing methods may lack the required sensitivity or speed for trace detection.

Purpose of the Study:

• To develop a highly sensitive fluorescence biosensing system for trace arsenic(III) detection.
• To utilize a target-triggered successive signal amplification strategy for enhanced sensitivity.
• To validate the biosensor's performance in real-world water samples.

Main Methods:

• Designing a fluorescence biosensor based on aptamer recognition of As³⁺.
• Employing Exonuclease III (Exo III)-mediated DNA recycling to generate DNAzymes.
• Utilizing DNAzymes to catalyze substrate cleavage, leading to amplified fluorescence signals.
• Incorporating magnetic separation for efficient processing.

Main Results:

• Achieved an ultrasensitive detection limit of 2 pM for As³⁺.
• Demonstrated excellent selectivity for As³⁺ over other metal ions.
• Successfully applied the biosensor for accurate As³⁺ determination in water samples.
• The system leverages synergetic signal amplification from Exo III and DNAzyme activity.

Conclusions:

• The developed fluorescence biosensor offers a sensitive, selective, and accurate method for As³⁺ detection.
• The target-triggered successive signal amplification strategy is effective for trace analyte monitoring.
• This platform shows potential as a universal approach for detecting various aptamer-binding molecules.