Printing materials in micro- and nano-scale: Systems for process control

Imprinting polymers is an outstandingly versatile and straightforward way for generating sensor materials. Combined with mass-sensitive devices they are e.g. also highly suitable for process control. We e.g. monitored the amount of methyl iodide above a reaction mixture of this compound and triethylamine. At the titration end point, the heatable QCM device indeed shows a significant frequency response to the reactant. When monitoring oxidative degradation processes in engine lubricants, applying MIP titanate nanoparticles leads to an increase in sensitivity by a factor of 2 compared to deposited thin films of the same material. With surface-imprinted polyurethanes, we succeeded in directly measuring insulin in aqueous solution over three orders of magnitude in concentration. Furthermore, fermenting yeast cells can directly be measured. To increase the reproducibility of the sensor signal, an artificial polymer stamp for preparing the MIPs is presented. (C) 2006 Elsevier B.V. All rights reserved.