Color Intensity Method for Hydrogel Oxygen Sensor Array

The oxygen imaging technique to obtain a 2-D distribution is a convenient method because it does not require individual addressing of each sensing element in a sensor array. Until recently, color charge coupled devices (CCDs) have rarely been used for oxygen imaging in spite of usefulness for analyzing the spectral content of images. In this work, a color CCD camera was used for luminescence intensity imaging. Two methods of color intensity analysis are investigated and compared. The first method is to analyze the total Red-Green-Blue (RGB) color intensity of the original color image. The second method involves extracting the red color element to enhance the sensitivity of oxygen measurement. Both commercial RedEye oxygen sensor patches and lab-made photopatterned hydrogel (polyethylene glycol) sensor arrays were used to verify these methods. The linearity and sensitivity of oxygen detection based on the red intensity analysis was improved to those of spectrometric measurement and total color intensity analysis. This method also has potential applications in lifetime imaging, multi-analyte detection, and simultaneous structural and functional imaging of biological systems.