ECL sensor with mobile technology (NSF funded)
Paper Diagnostics
The mobile technology is quickly becoming the hub of future biosensor development. Many mobile devices have built-in sensors, cameras that can serve as detectors for biosensors. We are developing an Electrochemiluminescence (ECL) sensor utilizing existing mobile technology, transforming what was traditionally an expensive and bulky biosensor technology into a portable and affordable one. ECL sensors work by a simple principle - when a small voltage is applied to an ECL chemical and the chemical emits lights in the visible spectrum. The small voltage can be provided by the mobile device itself and the emitted light can be captured by the cameras. Then the captured images can be analyzed by a mobile app. Developing such a mobile sensor will dramatically reduce the cost of biosensors by replacing the need for an expensive detector, a designated computer, and monitors. Our goal is to make this new sensor platform equivalent not only in performance to that of existing high-end biosensors, but also more affordable and for many different biosensor needs. The ECL biosensor can be used for diagnosis of biomarkers of various diseases such as cancer. Its inexpensive and ubiquitous nature will make an ideal platform to respond to the disaster rescue and recovery. This project involves collaboration between engineering, computer programming and molecular biology.
Soft sensor development
Biofuel industry has gained substantial attraction as alternative fuel for the petroleum derived fuels in order to mitigate major concerns raised by fossil fuel consumptions. Biofuels market size in U.S. is expected to be worth around US$ 307.01 billion by 2030 and thus a need for improving the process also increases.
In the biofuel industry, real time measurements of production variables such as ethanol and substrate are important in order to properly control the process for quality control and higher productivity; however, these measurements are conducted delayed or less frequently. We plan to develop a soft-sensor that uses easily accessible on-line measurement to estimate other hard-to-measure variables in real time.
QCM-D Sensor
Dr. Kwon is an expert in the QCM-D sensor and related biosensor measurement. She also workes with EIS system, and developed combined FET system that complement QCM-D measurement. A sensing unit of QCM-D sensor is a thin quartz crystal (diameter 2.5 cm, thickness 1mm) with thin gold electrodes coated in both sides. The crystal is piezoelectric resonators where the resonant frequency varies linearly with the mass of adsorbed layers on the surface. By measuring several frequencies and the dissipation it becomes possible to determine whether the adsorbed film is rigid or water-rich. The QCM-D sensor monitors dissipation, allowing biomolecular detection in liquid.
Mathematical Modeling and Simulation
Dr. Kwon's lab has been actively working on developing mathematical models for biosensors for simultaneous fluid, diffusion-convection, and mass adsorption, skin adsorption of mass and light proprgation, and fluid migration with reatction in paper medium. A commercial PDE solver, COMSOL is used to simulate multyphysics.