Assembling Surface Linker Chemistry with Minimization of Non-Specific Adsorption on Biosensor Materials

Area of Science:

• Surface chemistry
• Biosensor technology
• Materials science

Background:

• Biosensor performance relies on specific surfaces with minimal biofouling.
• Thiosulfonate-based linkers offer potential for robust self-assembling monolayers (SAMs).

Purpose of the Study:

• To develop and assess thiosulfonate-based SAMs for chemoselective probe immobilization.
• To investigate methods for reducing biofouling on biosensing interfaces.
• To compare surface attachment on sensor materials like Si3N4 and AlN.

Main Methods:

• Constructed SAMs on hydroxylated surfaces using thiosulfonate linkers.
• Immobilized thiol-containing probes in an aqueous, coupling-free manner.
• Evaluated biosensing performance for avidin detection using an acoustic wave device.
• Assessed biofouling using bovine serum albumin (BSA), IgG antibody, and goat serum.
• Systematically improved SAMs by incorporating oligoethylene glycol backbones and diluents.

Main Results:

• Achieved chemoselective immobilization of probes onto SAMs under aqueous conditions.
• Demonstrated the efficacy of the SAMs as a biosensing interface.
• Identified that short diluents are critical for significantly reducing biofouling.
• Compared linker attachment to Si3N4 and AlN surfaces.

Conclusions:

• Thiosulfonate-based SAMs provide a robust and reliable platform for biosensor development.
• The strategic use of short diluents in SAMs is essential for mitigating biofouling.
• This approach enhances biosensor specificity and durability for biological fluid applications.