PrintThis project aims at developing a novel approach based on optical fibre for the highly selective and sensitive analysis of catecholamines. The low time consuming of analysis and absence of any sample pre-treatment prior to analysis will provide instantaneous results and contribute to the improvement of quality of medical diagnostics. In a first step the biosensor will be assembled, tested and optimised for standard solutions. The biosensor will be constituted by a laser diode of 1 mW and 1550 nm, a quartz single-mode optical fiber (core and cladding diameters of 9 and 125 microm, respectively) inserted in quartz capillary tubing and a photodiode located at the end of the capillary tubing on the opposite side of the laser radiation. In a second step, it will be performed enzyme immobilisation in the optical fiber surface through encapsulation in a sol-gel film and tested for stability. Parameters such as pH, substrate concentration and enzyme concentration will be also studied in order to study their effects in the biosensor performance. The biosensor will also be tested for its performance using synthetic samples. The analytical results will be compared with the ones obtained by HPLC Electrochemical detector for the same synthetic samples. In a third step, the biosensor will be applied to real samples clinical (human urine and blood) and research (tissue perifusion fluid) samples. The human samples will be blood and urine either from healthy subjects or patients suffering from different diseases which likely affect catecholamine levels (e.g. Down's Syndrome). Blood and urine from experimental animals (rat, mouse) will be also tested with the biosensor.Finally the biosensor will be adjusted to miniaturization and a prototype will be built and tested with real samples.
