Optical detection in microfluidic systems

Optical detection schemes continue to be favoured for measurements in microfluidic systems. A selection of the latest progress mainly within the last two years is critically reviewed. Emphasis is on integrated solutions, such as planar waveguides, coupling schemes to the outside world, evanescent-wave based detectors and the field of opto-fluidics. The perspectives and limitations of the different solutions are discussed in terms of analytical performance and fabrication costs. There has been an increased focus on cheap solutions in polymer materials that are amenable for mass production in order to ease commercialisation of the devices. This work will hopefully result in more commercial products that benefit from integrated optics, because the impact on commercial devices so far has been modest.