Colour Metrology for Colourimetric Holographic Biosensor Application

A novel methodology is developed to identify colour information of the holographic pH sensor using modern smartphones by leveraging its integrated LED light source and CCD camera. This study addressed the difference in colour appearance of the same sample inspected with different devices. The colour metrology solution includes standardizing the lighting and perceiving condition, calibrating reference colour standards under standard colour measurement conditions, and calibrating the holographic sensor’s colour appearance taken by smartphone device by using calibrated reference colour standards. Results after calibration demonstrated a significant improvement in consistency, differences in HUE of biosensor captured by different smartphones can be improved by up to 50%. This confirms that the smartphone, as a measuring tool, coupled with this metrology solution is able to accurately and reliably measure the colour of holographic biosensors, offering a more consistent colourimetric analysis.