Electrochemical molecular beacon DNA biosensor for the detection and discrimination of the DF508 cystic fibrosis mutation

Paving the way towards continuous biosensing by implementing affinity-based nanoswitches on state-dependent readout platforms

Combining affinity-based nanoswitches with state-dependent readout platforms allows for continuous biosensing and acquisition of real-time information about biochemical processes occurring in the environment of interest.

Nucleic acid-based electrochemical biosensors for rapid clinical diagnosis: Advances, challenges, and opportunities

Clinical diagnostic tests should be quick, reliable, simple to perform, and affordable for diagnosis and treatment of diseases. In this regard, owing to their novel properties, biosensors have attracted the attention of scientists as well as end-users. They are efficient, stable, and relatively cheap. Biosensors have broad applications in medical diagnosis, including point-of-care (POC) monitoring, forensics, and biomedical research. The electrochemical nucleic acid (NA) biosensor, the latest invention in this field, combines the sensitivity of electroanalytical methods with the inherent bioselectivity of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). The NA biosensor exploits the affinity of single-stranded DNA/RNA for its complementary strand and is used to detect complementary sequences of NA based on hybridization. After the NA component in the sensor detects the analyte, a catalytic reaction or binding event that generates an electrical signal in the transducer ensues. Since 2000, much progress has been made in this field, but there are still numerous challenges. This critical review describes the advances, challenges, and prospects of NA-based electrochemical biosensors for clinical diagnosis. It includes the basic principles, classification, sensing enhancement strategies, and applications of biosensors as well as their advantages, limitations, and future prospects, and thus it should be useful to academics as well as industry in the improvement and application of EC NA biosensors.

A label-free, electrochemical SERS-based assay for detection of DNA hybridization and discrimination of mutations

A label-free, surface-enhanced Raman spectroscopy-based assay for detecting DNA hybridization at an electrode surface and for distinguishing between mutations in DNA is demonstrated. Surface-immobilized DNA is exposed to a binding agent that is selective for dsDNA and acts as a reporter molecule. Upon application of a negative potential, the dsDNA denatures into its constituent strands, and the changes in the spectra of the reporter molecule are monitored. This method has been used to distinguish between a wild-type, 1653C/T single-point mutation and ΔF508 triplet deletion in the CFTR gene. The use of dsDNA-selective binding agents as reporter molecules in a discrimination assay removes the burden of synthetically modifying the target to be detected, while retaining flexibility in the choice of the reporter molecule.