The Detection of Apolipoprotein E-epsilon 4 gene (APOE ϵ4) via Fluorescence Quenching of Quantum Dots Incorporated Magnetic Beads in Micro-fluidic Chip

Abstract

The APOE ϵ4 gene is a susceptibility gene or risk factor for Alzheimer's disease. The gene codes for a protein which limits the brain's ability to break down amyloid-beta, a protein that is toxic to the brain. In this study, we have prepared magnetic beads - CdSe/ZnS QDs-APOE probe DNA complexes for the detection of APOE DNA. QDs were conjugated to amine- functionalized magnetic beads by EDC/Sulfo-NHS coupling reaction. Thiol group modified single stranded probe oligonucleotides of APOE ϵ2 and APOE ϵ4 were immobilized on the surface of QDs to prepare magnetic bead-QDs-DNA complexes. APOE genes could be detected by fluorescence quenching of QDs by intercalation dye after hybridization. PDMS based micro-fluidic chips were prepared and the bead-QDs-DNA complexes were packed on the channel of the microfluidic chip. The APOE ϵ2 and APOE ϵ4 gene could be detected via fluorescence quenching of QDs on the channel.

Keywords:

• Alzheimer's disease
• APOE ϵ4 gene
• QD
• Microfluidic chip

Acknowledgment

This research was supported by the GRRC program of Gyeonggi province [(GRRC Gachon 2014-B01)].