Mathematical Model for Laboratory System of Bioluminescent Whole-Cell Biosensor with Optical Element

The fiber-optic biosensor with encapsuled bioreporters use a special optical element (OE) from pure silica with an active layer contents bioluminescent bioreporters was developed as a real in-situ detector for on-line measurement in remote localities. The active layer of biosensor contents bioluminescent bioreporters – genetic modified cells, which are sensitive to its surrounding environment-immobilized in silica matrix on the end of OE. Bioreporters are able to react by emission of visible light (≈500 nm) – bioluminiscence reaction (BL) – in presence of specific analyte. The genetic modified bacterial stain Pseudomonas putida TVA8 was chosen as biorecognition part of biosensor producing BL in the presence of benzene, toluene, ethylbenzene and xylens (BTEX). Very low level of BL signal was detected by high-sensitive photon-counter. The sensitivity of biosensor depends on a value of detected BL and it can be very low. The signal is also affected by number of cells (light sources) immobilized into the active layer and transmission through OE. Mathematical model of OE shape was developed based on geometric optics. The numerical model is built around the MATLAB scripting language. Simulation of ray transmission was calculated for OE with different shape.