Engineering New Aptamer Geometries for Electrochemical Aptamer-Based Sensors

Area of Science:

• Electrochemistry
• Biosensors
• Molecular Biology

Background:

• Electrochemical aptamer-based (E-AB) sensors offer a novel method for small molecule detection.
• These sensors utilize aptamers immobilized on electrodes, with redox markers for signal transduction.

Purpose of the Study:

• To optimize cocaine-detecting E-AB sensors by exploring novel aptamer architectures.
• To enhance signal transduction and sensor performance through structural modifications.

Main Methods:

• Designed and tested two new aptamer architectures: a poly-aptamer and a split aptamer with a thymine linker.
• Modified aptamer structures to position the redox tag further from the electrode in the target-free state.
• Evaluated sensor performance in terms of signal gain and selectivity in complex matrices like whole blood.

Main Results:

• The novel poly-aptamer and split aptamer constructs exhibited 2-3 times higher signal gains compared to the original architecture.
• All three tested sensor architectures demonstrated sufficient selectivity for direct use in undiluted whole blood.
• Successful detection of cocaine was achieved across all evaluated sensor designs in complex biological samples.

Conclusions:

• Optimized aptamer geometries significantly enhance the signaling efficiency of E-AB sensors.
• Novel aptamer designs enable sensitive and selective cocaine detection in challenging sample matrices.
• These findings contribute to the advancement of E-AB sensor technology for small molecule analysis.