Friday, April 10

Application of external micro-spectrophotometric detection for microchips
Erika Garcia, LSAMP Bridge to the Doctorate Scholar

Abstract: A microphotometer (Schnellphotometer) has been modified to precisely select very small parts of a microfluidic channel pattern of a chip and to measure light absorbance on a magnified area of the selected part of the channel. The viability of combining a projection microscope and a spectrophotometer for external absorbance measurements on disposable PDMS chips was studied. Besides the external direct detection above a microfluidic channel, the optical pathlength was lengthened by detecting in the region of the perpendicular exit port. Increasing the cross-sectional area of the zone of irradiation improved the signal to noise ratio and the limits of detection (LOD).