In this lecture, we continue the discussion on the oxygen sensor. It starts with a review of the measurement of O2 concentration levels through electrical currents. This is called an amperometric meter. Then, the subject shifts to glucose and the role of the pancreas in producing insulin to control glucose levels. However, in diabetics, the pancreas stops producing insulin and we come into the problem of detection. There is an enzyme called Glucose Oxidase (GOD) that converts glucose and O2 into Gluconic Acid which does not have the harmful effects of glucose, and Hydrogen Peroxide. This leads us to the application of the glucose sensor which has an outer cellophane membrane, a gel with GOD in the middle, and finally the O2 sensor mentioned at the beginning on top. The Glucose and O2 can get inside and the gel then creates the products. The more glucose we have, the less the concentration of O2 there is. This creates the idea that the current of the O2 sensor on top is proportional to the O2 concentration which is proportional to 1/Glucose Concentration.
My research group is focused on the application of sub-wavelength optical phenomena and fabrication methods to the development of novel devices and instrumentation for the life sciences. The group is highly interdisciplinary, with expertise in the areas of microfabrication, nanotechnology, computer simulation, instrumentation, molecular biology, and cell biology. In particular, we are working on biosensors based upon photonic crystal concepts that can either be built from low-cost flexible plastic materials, or integrated with semiconductor-based active devices, such as light sources and photodetectors, for high performance integrated detection systems.
Using a combination of micrometer-scale and nanometer-scale fabrication tools, we are devising novel methods and materials for producing electro-optic devices with nanometer-scale features that can be scaled for low-cost manufacturing. Many of our techniques are geared for compatibility with flexible plastic materials, leading to applications such as low cost disposable sensors, wearable sensors, flexible electronics, and flexible displays. Because our structures manipulate light at a scale that is smaller than an optical wavelength, we rely on computer simulation tools such as Rigorous Coupled Wave Analysis (RCWA) and Finite Difference Time Doman (FDTD) to model, design, and understand optical phenomena within photonic crystals and related devices.
In addition to fabricating devices, our group is also focused on the design, prototyping, and testing of biosensor instrumentation for high sensitivity, portability, and resolution. Advanced instruments enable high resolution imaging of biochemical and cellular interactions with the ability to monitor images of biochemical interactions as a function of time. Using the sensors and instrumentation, we are exploring new applications for optical biosensor technology including protein microarrays, biosensor/mass spectrometry systems, and microfluidics-based assays using nanoliter quantities of reagents. The methods and systems developed in the laboratory are applied in the fields of life science research, drug discovery, diagnostic testing, and environmental monitoring. -From Professor Cunningham's Faculty Profile
University of Illinois at Urbana-Champaign, Urbana, IL