A New Development of Photoacoustic Detection for Microchip-CE Using a Simple Pick-up Device

A new approach to laser-based non-fluorescence detection was developed for microchip-capillary electrophoresis (microchip-CE) utilizing an electrical pick-up device. An intensity-modulated laser beam was irradiated on the microchip, and an acoustic wave was then generated by the periodic thermal expansion. Detection of signals was performed by the measurement of the induced electromagnetic wave with the use of a pickup device. The signal magnitude showed a linear relationship with the laser power and applied voltage, while the acoustic signal displayed a linear dependence on the concentration of the sample over a wide range. The separation of dye mixtures is achieved by the use of this new detection method for microchip-CE.