(256m) New Nanostructured Oxygen Sensors for Biological Applications

Dissolved oxygen concentrations in live cells and cellular environments are critical for many physiological and pathological processes including metabolism, cell respiration/oxygen consumption, and tissue hypoxia. Among the many oxygen sensors, platinum(II)-5,10,15,20-tetrakis-(2,3,4,5,6-pentafluorophenyl)-porphyrin (PtTFPP) is known to be an excellent one due to its good responses to oxygen concentrations, high photostability, and high quantum efficiency as compared with others. Unfortunately, its extreme hydrophobicity limits its application in a biological environment. Herein, we will describe our results using various different amphiphilic block copolymers to incorporate typical oxygen probe of PtTFPP for enabling the application of the hydrophobic material in aqueous solution, achieving high brightness and water-soluble oxygen sensors. We will report the preparation of micelle-based oxygen sensors, their optical spectra, oxygen responses, and photo-stability. The sensors showed liner responses to dissolved oxygen with high reversibility, enabling their suitable application for measuring dissolved oxygen concentrations. The sensors did not show obvious cytotoxicity to cells. We have demonstrated that these sensors are applicable for cell respiration monitoring for microbes and eukaryotic cells with various cell densities. At a defined cell density, cell respiration velocity is relevant to cell viability, thus we have used the sensors for drug screening. For getting accurate analysis results in cell culture medium, we incorporated another fluorophore which does not respond to oxygen to prepare ratiometric fluorescent sensors.