An aptamer array for discriminating tetracycline antibiotics based on binding-enhanced intrinsic fluorescence

Area of Science:

• Biochemistry
• Analytical Chemistry
• Molecular Biology

Background:

• Tetracyclines are structurally similar antibiotics, making differentiation challenging.
• Aptamers offer specific molecular recognition capabilities.
• Intrinsic fluorescence of tetracyclines can be leveraged for detection.

Purpose of the Study:

• To identify and characterize aptamers capable of differentiating between oxytetracycline (OTC), tetracycline (TC), and doxycycline (DOX).
• To develop a sensitive and label-free detection method for tetracycline antibiotics using aptamers.

Main Methods:

• Selection and analysis of aptamer sequences targeting tetracyclines.
• Measurement of fluorescence enhancement upon aptamer-tetracycline binding.
• Development of a sensor array utilizing selective aptamers.
• Application of principal component analysis (PCA) for discrimination.

Main Results:

• Three aptamers (OTC43, OTC22, OTC2) were identified with selective fluorescence enhancement for OTC, DOX, and TC, respectively.
• Limits of detection (LOD) were as low as 0.3 nM for TC (OTC2), 0.4 nM for DOX (OTC22), and 0.7 nM for OTC (OTC43).
• A sensor array combined with PCA successfully discriminated between the three tetracyclines and other molecules.

Conclusions:

• Novel aptamers enable selective and sensitive detection of individual tetracycline antibiotics.
• Aptamer-based sensor arrays provide a powerful platform for differentiating structurally similar compounds.
• These aptamers hold promise for the development of diagnostic tools for tetracycline antibiotic monitoring.