Aptamer-based electrochemical sensors with aptamer-complementary DNA oligonucleotides as probe

Area of Science:

• Electrochemistry
• Biosensors
• Nucleic Acid Chemistry

Background:

• Aptamer-based electrochemical sensors typically use aptamers as probes.
• Existing methods face challenges in regeneration and generalizability.
• A new strategy is needed for improved aptasensor development.

Purpose of the Study:

• To develop a facile and general strategy for aptamer-based electrochemical sensors.
• To utilize complementary DNA (cDNA) as the primary probe for electrochemical sensing.
• To achieve high specificity and ready regeneration of the aptasensors.

Main Methods:

• Designed cDNA probes with complementary ends and labeled with a redox moiety (ferrocene) and thiol group.
• Hybridized labeled cDNA with target-specific aptamers to form double-stranded DNA (ds-DNA).
• Self-assembled ds-DNA onto gold electrodes to create electrochemical aptasensors.

Main Results:

• Target binding induced aptamer dissociation, causing cDNA to form a hairpin structure.
• Conformational change in cDNA altered the electrochemical signal of the redox moiety.
• The developed aptasensors demonstrated high specificity, ready regeneration, and good target responses.

Conclusions:

• The proposed strategy using cDNA as probes offers a new and general approach for electrochemical aptasensor development.
• This method provides good analytical properties and potential for various applications.
• The aptasensors are highly specific and easily regenerated, overcoming limitations of previous methods.