Electrochemical Nucleic Acid-Based Biosensing of Drugs of Abuse and Pharmaceuticals

Background: Studies on the interactions of DNA with small molecular drugs are currently performed both to explore their mechanism of action and to develop new drugs. Electrochemical biosensors offer a very promising alternative to more complex conventional techniques for drug determination due to rapidness, low cost, simplicity, high sensitivity and compatibility with use in different settings. In this review, selected electrochemical nucleic acid-based biosensing methods described so far for the determination of pharmaceuticals and illicit drugs are briefly overviewed, discussing their basics and main features. A section pointing out general conclusions and future directions in this field is also provided. Results: The 42 selected contributions described electrochemical platforms to determine drugs of interest by monitoring their specific interactions with nucleic acids (DNA and aptamers), DNA damage and specific DNA-protein interactions. The highlighted approaches reported the use of electrodes unmodified or modified with nanomaterials and/or polymers in which DNA-drug interaction was followed by electrochemical detection of DNA puric bases, active drug or diffusion-free markers, and monitoring changes in the surface layer morphology/permeability and charge transfer resistance using different electrochemical techniques. Conclusion: Although electrochemical nucleic acid biosensing approaches constitute an interesting option for drugs determination in terms of cost, simplicity and miniaturized instrumentation, validating exhaustively their performance in real samples against conventional methodologies and implementing them into portable and automatic high throughput devices, together with exploring novel electrode modifications with nanomaterials and polymers and studying in more detail their multiplexing ability for analysis of a large number of analytes, is still needed.