Preconcentration nanofluidic device

The nanofluidic preconcentration device can be considered an equilibrium gradient device using a steep electric field gradient and an opposing bulk flow to focus analytes [243]. Other equilibrium gradient techniques have also been implemented in microfluidic channels. These techniques include temperatare... 

Besides the benefits such as low consumption resulting from miniaturizing the fluidic components, phenomena specific to micro- and nanofluidic systems can also be harnessed to enhance electrochemical response. For example, Wang et al. introduced a preconcentrating device that could be... 

The use of recirculating flows for the preconcentration of samples in microfluidic devices is, like TGF and nanofluidic filtering (see later), a relatively new approach (early 2000s). The technique, which has been termed flow-induced electrokinetic trapping (FIET), involves the concentration and... 

The preconcentration techniques that have to date been most used in microfluidic devices have been presented in the preceding pages. Most of the techniques were originally developed for conventional CE or liquid chromatography and have (more or less simply) been adapted to microchips. FASS, ITP, and lEF are examples of these types of techniques. A few new techniques have been developed for the preconcentration of samples on microfluidic devices. TGF and nanofluidic filtering are both examples of techniques that have been developed solely for microfluidic chips. High enrichment factors can be achieved with both techniques, on the order of 10,000 and 1,000,000, respectively. Table 50.1 summarizes the top performers in each device category with respect to preconcentration factor and time. 

---