Toward a Plasmon-Based Biosensor throughout a Thermoresponsive Hydrogel

Area of Science:

• Biomaterials Science
• Nanotechnology
• Diagnostic Technology

Background:

• Thermoresponsive hydrogels offer tunable porosity for nanoparticle integration.
• Existing in vitro diagnostic (IVD) platforms require compatible substrates for advanced detection methods.
• AVAC technology provides precise detection of gold nanoparticles (AuNPs).

Purpose of the Study:

• To evaluate thermoresponsive hydrogels (TSHs) as substrates for AVAC technology in IVD.
• To ensure hydrogel permeability to AuNPs and non-interference with AVAC detection.
• To develop a hydrogel-coated silicon platform for enhanced diagnostic applications.

Main Methods:

• Fabrication of silicon-grafted hydrogel platforms ((Sil)-g-(PNIPAAm-co-MBA)) using varying cross-linker concentrations.
• Evaluation of hydrogel deposition methods: drop casting (DC), spin coating (SC), and 3D printing (3D).
• Characterization of hydrogel physical-chemical properties and validation of AuNP detection via AVAC technology.

Main Results:

• Drop casting yielded a homogeneous, thin hydrogel layer suitable for AVAC technology.
• The TSH successfully regulated nanoparticle absorption and allowed precise AuNP identification through the hydrogel matrix.
• The developed hydrogel platform meets prerequisites for integration into sandwich immunoassay devices.

Conclusions:

• Thermoresponsive hydrogels are viable dynamic substrates for AVAC-based IVD applications.
• Functionalization of hydrogels with biorecognition groups is the next step for biomarker detection.
• This approach combines 3D hydrogel structures with digital detection for advanced diagnostics.