Fabrication and Set-Up Optimization of Microbubble Resonator for Biosensing

Gabriela Hall

In Collaboration with Jie Liao and Jinran Qie

PI: Lan Yang (Micro/Nano Phonotics Lab)

Washington University in St. Louis

Abstract

Increasing the reliability, sensitivity, speed, and cost-effective nature of biological assays for medically relevant molecules holds great potential to improve medical practice and make it more widely available. Many researchers have tapped into the potential of microresonators for ultra-sensitive detection and assays of proteins1, 7, oligonucleotides2, pH3, temperature4, and more. Microresonators provide highly sensitive detection on the order of picomolar concentrations, cheap and fast fabrication, recyclability, label-free detection, rapid detection time, accuracy in complex media, and multiplexing5, 6. Examples of microresonators include microrings, microspheres, microbubbles, and microtoroids. To detect particles using microresonators, targets bind to the chemically altered surface and change the path of light traveling through the microresonators. This change is measured and used to detect individual particles or small concentrations of particles. This project explored two methods of fabricating microbubbles in the Micro/Nano Photonics Lab at Washington University in St. Louis. The bubbles were analyzed by determining their Q-factors and measuring their response to changes in salt concentrations flowing through the bubbles. By having a robust microbubble platform, various biomarkers can be quantified for multiple medical applications.