Reduction of interference between pH and optical output signals in a multimodal bio-image sensor

We have developed a low interference multimodal sensor for pH (power of Hydrogen) and optical imaging. The signal interference between pH and optical outputs is shown to be caused during pH sensing by the photogenerated electrons. We suppressed this interference by adding another charge accumulation region to the conventional multimodal sensor structure for measuring only the amount of photogenerated electrons and thereby discriminating between pH and optical signals.