Hybridization chain reaction and its applications in biosensing.

Area of Science:

• Biotechnology and Molecular Diagnostics
• Nanotechnology and Theranostics

Background:

• Sensitive detection of biomolecules is crucial for bioanalysis and disease diagnosis.
• Conventional polymerase chain reaction (PCR) requires enzymes and thermal cycling, limiting its application.
• Hybridization chain reaction (HCR) is an isothermal, enzyme-free amplification technique initiated by target analytes.

Purpose of the Study:

• To review the fundamentals of Hybridization Chain Reaction (HCR).
• To summarize recent advances in HCR-based biosensors for biosensing and RNA imaging.
• To discuss the challenges and future perspectives of HCR in biosensing and theranostic applications.

Main Methods:

• HCR utilizes a cascade of hybridization events to amplify signals.
• The process yields a long nicked double-stranded DNA (dsDNA) molecule.
• HCR operates under mild, enzyme-free conditions, contrasting with PCR.

Main Results:

• HCR has been successfully employed in developing sensitive and economic biosensors for various analytes (nucleic acids, small molecules, cells, proteins).
• HCR facilitates the assembly of nanostructures for targeted drug delivery, including anticancer drugs.
• Recent progress includes endogenous RNA imaging in living cells/animals and imaging-guided photodynamic therapy.

Conclusions:

• HCR is a powerful tool for signal amplification, enabling sensitive and efficient biomolecule detection.
• HCR applications extend to advanced RNA imaging and theranostics, offering a promising path for disease diagnosis and treatment.
• Further research into HCR holds significant potential for future biosensing and theranostic innovations.