A high sensitive detector detects and determines the presence of a very small amount of biological substances. The dye in the reduced state is substantially transparent to light of wavelengths used to read the optical medium, and the dye in the oxidized state absorbs light of wavelengths used to read the optical medium. The nitroso aromatic aldehyde is reacted with a reducing agent to form an indazole which ultimately can be used to form desired indazoles which are preferably pharmaceutically active products. The n-bit physical page of memory cells sensed correspond to n logical binary pages, one for each of the n-bits. The event and the absolute time for that event is then sent to a sequence of events reporting database, where this information is stored to form a system wide sequence of events log.