Use of quantum dots as mass and fluorescence labels in microarray biosensing

Area of Science:

• Biotechnology
• Nanotechnology
• Analytical Chemistry

Background:

• Interferometric reflectance imaging sensor (IRIS) is a sensitive technique for biomass detection.
• Quantum dots (QDs) offer unique optical and mass properties for bioassays.
• Current methods may lack absolute mass quantification or suffer from signal quenching.

Purpose of the Study:

• To demonstrate the efficacy of Quantum Dot (QD) mass labeling to enhance IRIS sensitivity.
• To explore the dual-mode capabilities of QDs for both mass and fluorescence detection.
• To investigate streptavidin-conjugated QDs (SA-QDs) as a probe in a microarray immunoassay.

Main Methods:

• Utilized a Quantum Dot (QD) mass label strategy with interferometric reflectance imaging sensor (IRIS).
• Employed streptavidin-conjugated QDs (SA-QDs) as a dual-role probe for mass and fluorescence detection.
• Developed a microarrays immunoassay to detect antibodies against β-lactoglobulin.

Main Results:

• Achieved enhanced sensitivity in the IRIS technique using QD mass labels.
• Demonstrated QDs' ability to provide absolute mass quantification.
• SA-QDs exhibited robust insensitivity to photobleaching and quenching, with a 655nm emission peak.
• Formed a detectable SA-QD monolayer of 6.2 ng/mm² under saturation conditions.

Conclusions:

• QD mass labeling significantly enhances the sensitivity of IRIS for biomass detection.
• QDs serve as effective dual-mode probes, offering both mass and fluorescence detection advantages.
• The developed SA-QD microarray immunoassay is a promising platform for allergen detection.