Homogeneous Binary Visual and Fluorescence Detection of Tetanus Toxoid in Clinical Samples Based on Enzyme-Free...

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Analytical Chemistry

Background:

• CdTe quantum dots can differentiate DNA-templated copper nanoparticles from Cu2+ ions.
• Aptamer-based assays offer high specificity for target biomolecules.
• Developing rapid and sensitive diagnostic tools for infectious diseases is crucial.

Purpose of the Study:

• To develop a simple aptamer-based toxoid test with dual readout capabilities.
• To achieve highly sensitive detection of tetanus toxoid.
• To validate the test in clinical settings and for patient monitoring.

Main Methods:

• Integration of CdTe quantum dots with aptamers for specific binding.
• Utilizing enzyme-free triple parallel hybridization chain reaction and cation exchange reaction.
• Employing inkjet printing for assay fabrication.
• Developing fluorescence and binary visual readouts (color and distance-based).

Main Results:

• Achieved a limit-of-detection (LOD) of 0.25 fg/mL for tetanus toxoid using fluorescence.
• Obtained LODs of 10 fg/mL (color) and 1 fg/mL (distance) for visual readouts.
• Successfully validated quantitative results in 84 clinical serum samples.
• Demonstrated accurate monitoring of tetanus toxoid levels in patients undergoing drug treatment.

Conclusions:

• The developed aptamer-based toxoid test provides a sensitive and versatile platform for tetanus toxoid detection.
• The dual readout system (fluorescence and visual) enhances applicability in diverse settings.
• A cutoff value of 5 fg/mL is recommended for diagnosing tetanus infection based on clinical validation.