Thermostable DNA immobilization and temperature effects on surface hybridization

Area of Science:

• Surface science
• Biotechnology
• Materials science

Background:

• Nucleic acid monolayers on solid supports are crucial for diagnostic and bioanalytical tools.
• Elevated temperatures enhance performance and provide insights into layer organization.
• Understanding thermostability is vital for applications requiring high-temperature operation.

Purpose of the Study:

• To compare the thermostability of two DNA oligonucleotide immobilization methods on gold surfaces.
• To investigate the impact of temperature on DNA monolayer organization and hybridization activity.
• To demonstrate the utility of thermostable DNA films in surface-based assays.

Main Methods:

• Immobilization of DNA oligonucleotides onto gold substrates using a polymercaptosiloxane anchor layer versus direct thiol conjugation.
• Thermostability assessment of DNA monolayers across a temperature range of 25–90 °C.
• Measurement of reversible surface melting transitions and temperature-dependent competitive hybridization.

Main Results:

• The polymercaptosiloxane anchor layer method demonstrated superior thermostability for DNA monolayers.
• Hybridization activity was retained even at 90 °C.
• Temperature significantly influenced the kinetics of competitive hybridization, with rapid equilibrium achieved at higher temperatures.

Conclusions:

• Thermostable DNA monolayers can be achieved using an anchor layer strategy, enhancing their utility in demanding applications.
• Surface melting transitions and competitive hybridization are temperature-sensitive processes.
• The findings provide a foundation for developing advanced temperature-robust nucleic acid-based biosensors.