Chromium functionalized diglyme plasma polymer coating enhances enzyme-linked immunosorbent assay performance

Area of Science:

• Biochemistry
• Materials Science
• Analytical Chemistry

Background:

• Optimizing antibody orientation and density on surfaces is crucial for sandwich enzyme-linked immunosorbent assays (ELISAs).
• Current methods face challenges in achieving consistent and effective antibody immobilization, impacting assay sensitivity and reliability.

Purpose of the Study:

• To develop and characterize a novel surface treatment for enhanced antibody immobilization in ELISAs.
• To investigate the role of chromium functionalization on a plasma polymer coating for improving antibody binding and orientation.

Main Methods:

• Utilized a diethylene glycol dimethyl ether plasma polymer (DGpp) coating functionalized with chromium in 96-well plates.
• Employed time-of-flight secondary-ion-mass-spectrometry (ToF-SIMS) and principal component analysis to analyze surface molecular species.
• Combined X-ray photoelectron spectroscopy (XPS) with ToF-SIMS for comprehensive surface characterization.

Main Results:

• Achieved a tenfold improvement in ELISA signal intensity with the DGpp+Cr surface treatment compared to untreated surfaces for equivalent antibody amounts.
• Identified ion fragments indicative of antibody binding sites (lysine, methionine, histidine, arginine) complexed with chromium.
• Demonstrated antibody binding via a chromium complex on the functionalized surface.

Conclusions:

• The DGpp+Cr surface treatment significantly enhances antibody immobilization and orientation.
• This novel surface modification strategy shows great promise for improving the sensitivity and efficacy of sandwich ELISAs.
• The findings provide a foundation for developing more robust and sensitive diagnostic assays.