Introduction
Microfluidic systems have been widely recognized as a new
emerging technology for the development of microanalytical
systems, especially for bioassays.1,2 Microfluidic systems exploit
the properties of liquid having low Reynolds number, such as
laminar flow and diffusion-induced mixing.1,3,4 Such systems
usually can be identified as having one dimension of the channel
less than 1 mm down to only tens of micrometres.4–6 Most of the
microfluidic devices are made u