Surface-immobilized and self-shaped DNA hydrogels and their application in biosensing

Area of Science:

• Biomaterials Science
• Biosensor Technology
• Nanotechnology

Background:

• Hydrogels are valuable in biosensing due to biocompatibility and 3D scaffolding, but integration with surface biosensing systems remains limited.
• Existing hydrogel applications in biosensing face challenges in stability and direct detection of analytes in complex matrices like serum.

Purpose of the Study:

• To develop and characterize surface-immobilized pure DNA hydrogels for advanced biosensing applications.
• To demonstrate the utility of DNA hydrogels in direct colorimetric and electrochemical detection of specific biomarkers in serum.
• To establish a recyclable and stable biosensing platform using enzyme-immobilized DNA hydrogels.

Main Methods:

• Synthesis of surface-immobilized pure DNA hydrogels via a surficial primer-induced strategy on transparent ITO electrodes.
• Characterization of hydrogel stability and enzyme encapsulation capabilities.
• Direct colorimetric and electrochemical detection of hydrogen peroxide and bilirubin in serum samples.

Main Results:

• Successful construction of a DNA hydrogel 3D scaffold on an ITO electrode, facilitating dual-mode measurements.
• Demonstrated stable enzyme wrapping within the hydrogel, maintaining activity under various conditions.
• Achieved sensitive detection limits for hydrogen peroxide (22 nM colorimetric, 13 nM electrochemical) and bilirubin (32 nM) in serum.
• Showcased regeneration and recyclability of the enzyme@hydrogel system for multiple detection cycles.

Conclusions:

• Surface-immobilized DNA hydrogels represent a novel and effective platform for direct biosensing in complex biological samples.
• This approach overcomes limitations of traditional hydrogel applications, enabling sensitive and stable detection of biomarkers.
• The developed DNA hydrogel biosensing system holds significant potential for clinical diagnostics and environmental monitoring.