Optical detection methods for lab on a chip systems

Optical detection methods, such as laser induced fluorescence, are well suited for high-sensitivity biochemical analysis on miniaturised platforms. While instrumentation for fluorescence sensing is well-established for conventional systems, the application of these technologies to lab on a chip (LOC) platforms prohibit the use of these systems as portable, point-of-care (POC) medical diagnostics due to the size and cost of these components. In this work we have developed several novel methods to eliminate the requirement for conventional bulk optics. This is accomplished through the direct replacement of these components with integrated optics and through the use of non-imaging optics by instead relying on the proximity between components to achieve high optical efficiencies. We demonstrate methods for on-chip light delivery using integrated optical waveguides with comparable sensitivity to conventional detection systems. In an extension to this work, dye-doped waveguides are fabricated which act as integrated optical filters, removing the need for external dielectric interference filters. Finally, we report the development of a novel hybrid fluorescence-based capillary electrophoresis (CE) system. This system consists of a polymer microfluidic chip and a high-voltage CMOS microchip capable of providing optical detection as well as supplying the high-voltage required for CE. This system has the capability of being integrated into a portable "USB-key" style platform.