Temperature measurement by color analysis of fluorescent spectrum using cell investigation tool impregnated with quantum dot for cell measurement on a microfluidic chip

In this paper, we proposed cell investigation tool for measurement of physiological conditions of single cell. We developed a novel temperature measurement method using temperature dependence of the quantum dot. The cell investigation tool encapsulates the quantum dot and adheres to the cell membrane. These tools can be manipulated in a solution by optical tweezers. We proposed image processing of the tools using the color information for temperature measurement. We calibrated the temperature using the tool impregnated with quantum dot by several color spaces such as HSV and YCrCb (H: hue, S: saturation, V: values (brightness). Y: brightness, Cr: color difference of red, Cb: color difference of blue). Y and Cr represent the monotone decrease according to the temperature increase, while H and Cb do not represent monotone variation. Measurement value by Cr is stable rather than the values by Y and V information because the color difference is robust against brightness fluctuation. From these results, we confirmed temperature measurement using Cr information suitable for cell analysis. Sensitivity is −1.3 %/K and accuracy is 0.3 K.