Hydrogel with chains functionalized with carboxyl groups as universal 3D platform in DNA biosensors

Area of Science:

• Biomaterials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Traditional planar surfaces limit DNA immobilization efficiency for biosensors.
• Developing 3D platforms can enhance probe availability and sensor performance.
• Hydrogels offer versatile matrices for biomolecule integration.

Purpose of the Study:

• To develop and characterize a novel N-isopropylacrylamide-based hydrogel for DNA immobilization.
• To evaluate the hydrogel's performance as a 3D platform for DNA hybridization and sensing.
• To determine the optimal hydrogel composition for enhanced DNA sensing capabilities.

Main Methods:

• Synthesis of N-isopropylacrylamide hydrogels with varying grafted carboxyl group content.
• DNA immobilization and hybridization studies using quartz crystal microbalance, electrochemical impedance spectroscopy, chronoamperometry, and ICP-LA.
• Reusability and stability assessment of the DNA-sensing layer.

Main Results:

• Hydrogel platform achieved DNA immobilization exceeding planar surfaces by over tenfold.
• Optimal carboxyl group content determined to be 5%, ensuring high DNA availability for hybridization.
• Achieved a detection limit of approximately 8x10(-13) M for target DNA, a significant improvement over planar sensors.

Conclusions:

• The 3D hydrogel platform provides a highly efficient and reusable matrix for DNA immobilization and sensing.
• The optimized hydrogel composition ensures robust analytical performance and superior detection limits.
• This technology represents a substantial advancement for sensitive and repeatable DNA detection in biosensing.