Oxygen flux fluorescence lifetime imaging

• Published in: Sensors and actuators. B, Chemical Vol. 38; no. 1; pp. 110 - 115
• Main Authors: Hartmann, Paul, Ziegler, Werner, Holst, Gerhard, Lübbers, Dietrich W.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 1997; Amsterdam Elsevier; New York, NY
• Subjects: Analytical biochemistry: general aspects, technics, instrumentation; Analytical chemistry; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Chemistry; Exact sciences and technology; Fluorescent lifetime imaging (FLIM); Fundamental and applied biological sciences. Psychology; Luminescent sensors; Oxygen; Phase-resolved spectroscopy; Skin; Spectrometric and optical methods; Oxygen; Skin; Luminescent sensors; Phase-resolved spectroscopy; Fluorescent lifetime imaging (FLIM); Flux; Optical sensor; Surface analysis; Chemical sensor; Fluorescence spectrometry; Lifetime; Partial pressure; Imaging; Luminescence quenching; Concentration distribution; Ruthenium complex
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/S0925-4005(97)80179-7

We describe a device capable of imaging distributions of surface PO 2 as well as oxygen flux (e.g., into the human skin). Oxygen is monitored by a phase-angle-sensitive imaging technique using the effect of luminescence lifetime quenching of ruthenium complexes incorporated into a polymer layer system. The dyes are excited by modulated radiation of blue light-emitting diodes. The phase-shifted luminescence is detected by an intensified CCD camera. Several modulation techniques have been comparatively investigated. The obtained images correspond pixel-by-pixel to the local luminescence lifetimes, which are a direct measure for the distribution of surface PO 2, or alternatively for the oxygen flux through a permeable diffusion barrier. For an illuminated sensor area of 10 cm 2 and a spatial resolution of 1 mm at the sensor layer, the oxygen resolution is better than Δ PO 2 = 0.3 torr in the absence of oxygen, and better than Δ PO 2 = 4 torr at PO 2= 160 torr.