Microfluidic devices synthesis

Ono, Y., Kitajima, M., Daikoku, S., Shiroya, T., Nishihara, S., Kanie, Y., Suzuki, K., Goto, S., and Kanie, O. (2008) Sequential enzymatic glycosyl-transfer reactions on a microfluidic device synthesis of a glycosaminogly-can linkage region tetrasaccharide. Lab Chip, 8, 2168-2173. 

Mitchell, M. C., Spikmans, V., Bessoth, F., Manz, a., de Mello, A., Towards organic synthesis in microfluidic devices multicomponent reactions for the construction of compound libraries, in van den Berg, A., Olthuis, W., Bergveld,... 

An additional advantage of using microfluidic devices, which we do not have the space to discuss in detail here, is the absence of turbulence (Koo and Kleinstreuer, 2003). In the context of nanoparticle synthesis, turbulence gives rise to unpredictable variations in physical conditions inside the reactor that can influence the nature of the chemical product and in particular affect the size, shape, and chemical composition. In microfluidic devices, turbulence is suppressed (due to the dominance of viscous over inertial forces) and fluid streams mix by diffusion only. This leads to a more reproducible reaction environment that may in principle allow for improved size and shape control. 

Several academic partners and Siemens Medical Solutions USA Inc. (Molecular Imaging) in Culver City, USA, made the synthesis of an [18F]fluoride-radiolabeled molecular imaging probe, 2-deoxy-2-[18F]fluoro-D-glucose in an integrated microfluidic device (see Figure 5.1) [21]. Five sequential processes were made, and they are [18F]fluoride concentration, water evaporation, radiofluorination, solvent exchange and hydrolytic deprotection. The half-life of [lsF]fluorine (t1/2 = llOmin) makes rapid synthesis of doses essential. This is one of the first examples of an automated multistep synthesis in microflow fashion. 

Microfluidic techniques have been recently used for the synthesis of microgel particles with dimensions of 1-30 pm. In these methods, microfluidic devices are used that provide emulsification of polymer solutions followed by physical [27, 28] or chemical [29] crosslinking. 

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. 

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