Microfluidic chips advantages

Several sample pre-concentration strategies have been devised to enrich dilute samples. The microfluidic chip has the advantage to integrate various microstructures to achieve sample pre-concentration by stacking, extraction, or other methods. 

In conclusion, the advantages of microfluidic devices, parallel synthesis, and combinatorial approaches can be merged to integrate a fluorescent chemical sensor array in a microfluidic chip. Fluorescent microchannel array can be produced by parallel synthesis of fluorescent monolayers covalent attached to the walls of glass microchannels. 

Lockery et al. [32] (Fig. 4c) and Park et al. [33] constructed micropillar structures in microfluidic chips to mimic the natural soil environment where C. elegans live in the wild, and investigated the mobility behavioral of the worms in this artificial soil . These works showed the unique advantages of manipulating individual C. elegans and the capability for parallel analysis of microfluidic platform. 

An alternative option to packed channels is the use of monolithic materials, which may have many of the same benefits as packed beds, including high surface area and easily controlled surface chemistry. However, a distinct advantage of monoliths is the ability to prepare them easily and rapidly via polymerization of liquid precursors within the channels of the microdevice without the need for any retaining structures. Despite the popularity of monolithic capillary columns for separations of a variety of low and high molecular weight compounds in HPLC mode, > their first application in microfluidic chips dates back only to 2005. 

We have discussed different functional parts of microfluidic chips that are necessary for on-chip chemical cytometry. In order to take the full advantage of miniaturization, in chemical cytometry, different functional components need to be properly integrated into a microchip. In this section, we will overview some examples of highly integrated microfluidic chips with specific applications for chemical cytometry to show the current status in this research area. 

From aforementioned data, we know that increasing the concentration of the DNA probes in the microfluidic channel is one way to enhance the hybridization efficiency. Craisidering that one of the advantages of microchannels is the high surface-to-volume ratio, surfaces of the microfluidic structure can be the solid support for immobilizing the capturing DNA probe to increase the concentration of the DNA probes efficiently. In such surface-based DNA hybridization microfluidic chips, DNA probe molecules are usually immobilized mito the wall of the microchannel. One of the limitaticais of the surface-based DNA hybridization chips lies in... 

Optofluidics holds the most potential in lab-on-a-chip application. Being compatible with conventional microfluidics is the key advantage of elastomer-based tunable optofluidic devices. PDMS microfluidic chips are extensively utilized in biological and chemical studies. Due to similarities in materials and fabrication methods, PDMS-based tunable optofluidic devices can be easily integrated with other PDMS-based microfluidic devices to enable more complex and multiplexed functions. For example, tunable dye laser sources can be used... 

Another strategy to avoid packing beads in a microfluidic device is in situ polymerization of a porous monolithic stationary phase. Svec et al. [5] have formed monolithic columns in microfluidic chips by using methacrylate chemistry to form reversed phase or ion exchange stationary phases. Preconcentration was used to increase the concentration of GFP by a factor of 10. Another advantage to this technique lies in the ability to control the porosity of the monolith. The ability to control the porosity decreased the back pressure allowing for flow rates as high as 10 pl/min. 

Monolithic stationary phases have the same advantages as packed chromatographic beds in a capillary or a microchannel for electrochroma-tographic analysis, including high surface area and easily controlled surface chemistry. In particular, the preparation of monolithic materials is relatively easy as a prepolymerization solution with low viscosity is simply introduced into the channels. The resulting monoliths in microfluidic chips are well anchored onto the inner walls of... 

The same-single-cell analysis conducted in a microfluidic chip has demonstrated the advantages in identifying MDR modulators and in quantifying the MDR reversal effect of dmg candidates during the dmg efflux stage. A mathematical model based on the Michaelis-Menten... 

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