Microfluidics in Biology and Genosensor Construction

We describe key stages in the development of a genosensor-based bioanalytical complex capable of functioning in a micro/nanofluidic system (MNFS), which is intended for detecting damaging agents in liquid media. Using the LIGA technology, we have developed an MNFS with a channel width of a few microns or more. Methods of (i) processing microfluid channels for positioning bacterial cells-genosensors and (ii) detecting fluorescent signals in a microfluid module are developed. A search for promoters ensuring the response of genosensor structures to a broad range of damaging factors of the external environment is carried out using a bioinformatics approach (based on GenSensor database). An experimental genosensor has been constructed based on the dps gene promoter of E. coli and the pRS-GFPvaa vector plasmid. It is shown that an E. coli/pDps-gfp genosensor in a microfluid module responds by GFPvaa protein synthesis to the presence of oxidative stress agents and agents capable of penetrating membranes in the same range of concentrations as those outside the module. The results of our investigation show that the proposed interdisciplinary approach can be used for obtaining bacterial cells-genosensors capable of functioning in MNFSs and detecting damaging factors of the external environment.