EAPSI: Designing Microfluidic Tools with Applications in the Development of Small Molecule Detection Sensors

Acevedo Andrew J, Allston MA

Investigators

Abstract

The detection and quantification of small molecules is of great importance to fundamental biological and environmental research, pharmaceutical development, and clinical practice. Oligonucleotide-based sensors provide a robust and powerful option for the detection of small molecules, but the development of these sensors has been hindered by the difficulty of separating potential sensor molecules from inert species. Droplet-based microfluidic technologies are uniquely situated to address these issues; these technologies allow for the separation and handling of individual sensor molecules and small molecule targets. This project will focus on the design and characterization of a droplet-generating microfluidic device with improved efficiencies and functionality over existing devices. This research is being done in collaboration with Dr. Saif Khan, an expert in droplet-based microfluidics, at the National University of Singapore. Aptamers, short oligonucleotides that bind targets with high affinity and specificity, are promising new tools for small molecule detection that overcome problems with current antibody based sensors, namely high production costs and low thermal and biochemical stability. However, the development of aptamers for small molecule targets has not been fully scaled up due to issues with partitioning aptamer candidates from large starting libraries of oligonucleotides. Droplet-based microfluidics can be utilized to overcome the partitioning issues as water-in-oil droplets provide a platform for the separation and handling of single oligonucleotides at both the amplification and selection stages during the aptamer development process. In order for microfluidic devices to be a viable tool for the aptamer development process, the devices require very high rates of droplet generation. The project aims to improve the rate of droplet generation of the 3D microfluidic droplet generators developed in the Khan lab. The project will also explore how channel dimensions, continuous phase composition, and the flowrate ratio between continuous phase and dispersed phase affect droplet diameter and thermal stability. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the National Research Foundation of Singapore.