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

小分子的检测和定量对基础生物学和环境研究、药物开发和临床实践具有重要意义。基于寡核苷酸的传感器为小分子检测提供了一个强大的选择，但这些传感器的发展一直受到从惰性物质中分离潜在传感器分子的困难的阻碍。基于液滴的微流体技术是解决这些问题的独特之处；这些技术允许分离和处理单个传感器分子和小分子目标。该项目将专注于设计和表征一种产生液滴的微流体装置，该装置比现有装置具有更高的效率和功能。这项研究是与新加坡国立大学基于液滴的微流体专家赛义夫·汗博士合作完成的。适配体是一种短的寡核苷酸，具有高亲和力和特异性，是小分子检测的新工具，克服了目前基于抗体的传感器的问题，即生产成本高，热和生化稳定性低。然而，由于从大型寡核苷酸起始文库中划分适体候选体的问题，小分子靶标适体的开发尚未完全扩大。基于液滴的微流体可以用来克服分配问题，因为油中水滴在适体开发过程中的扩增和选择阶段为单个寡核苷酸的分离和处理提供了平台。为了使微流控装置成为适体开发过程的可行工具，该装置需要非常高的液滴生成速率。该项目旨在提高可汗实验室开发的3D微流控液滴发生器的液滴生成速率。该项目还将探索通道尺寸、连续相组成以及连续相与分散相的流量比对液滴直径和热稳定性的影响。该奖项由美国国家科学基金会和新加坡国家研究基金会共同资助，隶属于东亚和太平洋暑期研究所项目，支持美国研究生进行暑期研究。

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.