Re-engineering aptamers to support reagentless, self-reporting electrochemical sensors

Area of Science:

• Biosensors and electrochemical sensing
• Biotechnology and aptamer engineering
• Analytical chemistry and molecular recognition

Background:

• Electrochemical aptamer-based (E-AB) sensors combine aptamer specificity with electrochemical detection for versatile biosensing.
• These sensors can detect targets in complex samples like blood without extensive sample preparation.
• Aptamer selection does not inherently yield conformation-switching architectures needed for efficient E-AB signaling.

Purpose of the Study:

• To systematically compare different aptamer re-engineering strategies for E-AB sensors.
• To evaluate the impact of aptamer architecture on signal gain in E-AB sensors.
• To determine if optimal switching geometries are sequence-dependent.

Main Methods:

• Investigated aptamer re-engineering approaches for E-AB sensors.
• Utilized aptamers specific to adenosine triphosphate (ATP) and human immunoglobulin E (IgE).
• Quantified signal gain across various engineered aptamer constructs.

Main Results:

• Multiple aptamer architectures can support E-AB signaling.
• Signal gain varied significantly (over two orders of magnitude) across different constructs.
• Observed signal gain ranged from -10% to 200% for ATP sensors.
• Optimal switching architecture was found to be specific to the aptamer sequence.

Conclusions:

• Aptamer re-engineering is critical for maximizing signal gain in E-AB sensors.
• The optimal aptamer conformation-switching architecture is sequence-dependent.
• This study provides insights for designing high-performance E-AB biosensors.