Protein microarray scanning in label-free format by Kelvin nanoprobe

Area of Science:

• Biophysics
• Analytical Chemistry
• Materials Science

Background:

• Protein microarrays are crucial for biological research and diagnostics.
• Label-free detection methods are highly desirable for simplifying microarray analysis.
• Surface potential changes can indicate biochemical interactions.

Purpose of the Study:

• To investigate the use of scanning Kelvin nanoprobe technology for detecting surface-immobilized proteins in a microarray format.
• To evaluate the capability of this technique for analyzing protein deposition and interactions.
• To establish a novel label-free method for protein microarray analysis.

Main Methods:

• Surface-immobilized proteins were deposited on various substrates (amine-coated glass slides, gold, indium tin oxide).
• Time-of-flight secondary ion mass spectrometry (TOF-SIMS) was used to characterize protein deposition.
• Scanning Kelvin nanoprobe was employed to measure surface potential changes, detecting antibody-antigen interactions.

Main Results:

• TOF-SIMS confirmed protein deposition characteristics on different substrates.
• Scanning Kelvin nanoprobe demonstrated label-free detection of antibody-antigen interactions.
• High inter-spot reproducibility and homogeneity analysis at 100 nm resolution were achieved.
• This represents the first report of surface potential detection in protein microarray technology.

Conclusions:

• Scanning Kelvin nanoprobe is a viable label-free technique for protein microarray analysis.
• The method provides high-resolution imaging and reliable detection of biochemical interactions.
• This technology offers a promising new avenue for sensitive and efficient protein analysis.