A s prayable luminescent pH sensor and its use for wound imaging in vivo

• Published in: Experimental dermatology 2012-12, Vol.21 (12), p.951-953
• Main Authors: Schreml, Stephan, Meier, Robert J., Weiß, Katharina T., Cattani, Julia, Flittner, Dagmar, Gehmert, Sebastian, Wolfbeis, Otto S., Landthaler, Michael, Babilas, Philipp
• Format: Article
• Language: English
• ISSN: 0906-6705; 1600-0625
• DOI: 10.1111/exd.12042

Non‐invasive luminescence imaging is of great interest for studying biological parameters in wound healing, tumors and other biomedical fields. Recently, we developed the first method for 2 D luminescence imaging of p H in vivo on humans, and a novel method for one‐stop‐shop visualization of oxygen and p H using the RGB read‐out of digital cameras. Both methods make use of semitransparent sensor foils. Here, we describe a sprayable ratiometric luminescent p H sensor, which combines properties of both these methods. Additionally, a major advantage is that the sensor spray is applicable to very uneven tissue surfaces due to its consistency. A digital RGB image of the spray on tissue is taken. The signal of the p H indicator (fluorescein isothiocyanate) is stored in the green channel ( G ), while that of the reference dye [ruthenium(II)‐tris‐(4,7‐diphenyl‐1,10‐phenanthroline)] is stored in the red channel ( R ). Images are processed by rationing luminescence intensities ( G / R ) to result in pseudocolor pH maps of tissues, e.g. wounds.