Use of microelectrodes for electrochemiluminescent detection in microfluidic devices

Microfluidic devices allow for fast detection with little reagent consumption. They also offer portability and the ability to mimic biological systems. Currently, many microfluidic devices are a hybrid of the microchip components, such as flow channels and wells, and larger instrumentation. There is a need to develop miniaturized detectors for lab-on-a-chip applications. Electrochemical detection methods have the advantage of ease of miniaturization. The electrochemical method, electrochemiluminescence, has the potential to be miniaturized and incorporated into a lab-on-a-chip device. As in other electrochemical methods, electrochemiluminescence is straightforward to miniaturize, but also possesses the sensitivity of a fluorescence detection method. In our laboratory, we have been developing carbon ink microelectrodes as the working electrode for a miniaturized electrochemiluminescence system. Since the signal is proportional to the electrode area, the challenge has been to maximize the signal-to-noise ratio and maintain low detection limits as the electrode size decreases.