Redox reaction-modulated fluorescence biosensor for ascorbic acid oxidase assay by using MoS₂ quantum dots as...

Area of Science:

• Biochemistry
• Materials Science
• Analytical Chemistry

Background:

• Ascorbic acid oxidase (AAO) plays a crucial role in biological processes.
• Accurate detection of AAO is essential for diagnostics and research.
• Existing detection methods may lack sensitivity or selectivity.

Purpose of the Study:

• To develop a sensitive and selective fluorescence (FL) biosensor for ascorbic acid oxidase (AAO) detection.
• To establish a detection platform based on fluorescence resonance energy transfer (FRET).
• To apply the developed biosensor for AAO determination in biological samples.

Main Methods:

• Fabrication of a FRET system using MoS2 quantum dots (MQDs) as donors and CoOOH nanoflakes as quenchers.
• Utilizing the redox reaction between ascorbic acid (AA) and CoOOH for signal recovery.
• Leveraging the enzymatic activity of AAO to re-quench the FL signal for sensitive detection.

Main Results:

• The FRET-based biosensor demonstrated effective quenching and recovery of FL signals.
• A sensitive detection range for AAO was established from 2 to 40 mU mL⁻¹.
• A low limit of detection (LOD) of 0.8 mU mL⁻¹ and limit of quantification (LOQ) of 2.6 mU mL⁻¹ were achieved.
• The biosensor exhibited high sensitivity and selectivity for AAO determination.

Conclusions:

• A sensitive and selective FL biosensor for AAO assay was successfully developed.
• The biosensor is based on the FRET mechanism between MQDs and CoOOH nanoflakes.
• The proposed method shows great potential for practical applications in determining AAO in human serum samples.