Promiscuous dye binding by a light-up aptamer: application for label-free multi-wavelength biosensing

Area of Science:

• Biochemistry
• Molecular Biology
• Analytical Chemistry

Background:

• Label-free DNA aptamers offer stable, cost-effective signal transduction for biosensing.
• The dapoxyl DNA aptamer DAP-10-42 exhibits unique binding promiscuity with fluorogenic dyes.

Purpose of the Study:

• To develop a versatile aptasensor using DAP-10-42 for detecting specific gene mutations.
• To enable direct detection of a katG gene fragment from Mycobacterium tuberculosis associated with isoniazid resistance.

Main Methods:

• Design of a split DAP-10-42 aptasensor.
• Utilizing the aptamer's promiscuity to bind various fluorogenic dyes for signal generation (500-660 nm).
• Integration with nucleic acid sequence-based amplification (NASBA) for enhanced sensitivity.

Main Results:

• The DAP-10-42 aptamer successfully functions as a sensor with different dyes, emitting fluorescence at varied wavelengths.
• A split aptasensor was designed for specific detection of the katG gene fragment.
• Direct and efficient detection of the target gene fragment was achieved in a protein-containing NASBA sample.

Conclusions:

• The DAP-10-42 aptamer serves as a versatile platform for developing fluorescence-based biosensors.
• This aptasensor enables sensitive detection of drug resistance-conferring mutations in Mycobacterium tuberculosis.
• The findings support the broad applicability of this aptamer in various biosensing applications.