Label-free reading of microarray-based proteins with high throughput surface plasmon resonance imaging

Area of Science:

• Biophysics
• Analytical Chemistry
• Materials Science

Background:

• Surface Plasmon Resonance (SPR) imaging is an emerging technology for label-free detection.
• Protein discrimination is crucial in various biological and diagnostic applications.

Purpose of the Study:

• To develop and demonstrate a simple, high-throughput method for discriminating different proteins using SPR imaging.
• To investigate the potential of SPR imaging for detecting protein structural changes via denaturation.

Main Methods:

• Fabrication of a protein array including bovine serum albumin (BSA), poly-l-lysine (PL), casein, and lactate dehydrogenase (LDG) on a gold surface.
• Utilizing SPR imaging to detect immobilized proteins based on variations in reflected light intensity and incident angular position.
• Inducing protein denaturation using 6M Guanidine Hydrochloride (GdnHCl) solution to observe changes in SPR signals.

Main Results:

• SPR imaging successfully discriminated between different immobilized proteins on the sensor surface.
• Obvious changes in reflected intensity were observed after protein denaturation, indicating alterations in molecular structure.
• The study achieved excellent chip-to-chip reproducibility for label-free protein discrimination.

Conclusions:

• SPR imaging is an effective and reproducible method for label-free discrimination of various proteins.
• SPR signal changes correlate with molecular structural alterations during protein denaturation.
• This technique holds promise for sensitive protein analysis and structural monitoring.