Label-Free and High-Throughput Detection of Biomolecular Interactions Using a Flatbed Scanner Biosensor

Area of Science:

• Biomedical Engineering
• Optical Biosensing
• Microarray Technology

Background:

• Fluorescence microarray detection offers sensitivity but suffers from probe immobilization variability and poor repeatability, hindering accurate quantification.
• Existing systems require calibration to ensure reliable and reproducible results.

Purpose of the Study:

• To develop a novel, label-free, high-throughput optical biosensor for the calibration of fluorescence microarrays.
• To demonstrate the transformation of a low-cost flatbed scanner into an Interferometric Reflectance Imaging Sensor (IRIS).

Main Methods:

• Utilized a commercial flatbed scanner with hardware and software modifications to create an IRIS.
• Developed label-free detection methods for DNA hybridization and antibody immobilization on microarrays.
• Achieved rapid scanning speeds for high-throughput analysis.

Main Results:

• Demonstrated a noise floor of approximately 30 pg/mm² for label-free detection.
• Achieved a scan speed of 5 seconds for a 2 mm × 2 mm area (50 seconds for 10 averaged frames).
• Successfully detected DNA hybridization and antibody immobilization without labels.

Conclusions:

• The developed IRIS is a cost-effective, high-throughput, label-free biosensor suitable for calibrating fluorescence microarrays.
• This system can enhance the quantification capabilities of existing fluorescence-based platforms.
• It holds potential as a standalone sensor in low-resource settings and for quality control in DNA and protein detection.