Sensitivity and photoperiodism response of algae-based biosensor using red and blue LED spectrums

An algae-based biosensor is investigated using dissolved oxygen levels producing from photosynthesis mechanism and from photoperiodism response time which describes the plant's reaction to light. This paper presents the sensitivity factor in the form of dissolved oxygen rate production level and response time of green algae-based biosensor, which is stimulated using artificial light of LEDs blue (480 nm) and red (650 nm). An amperometric electrode with two green algae as bioreceptors Chlorella kessleri and Chlorella sp. were tested in the biochip C chamber. A sample of 150µL algae with a density of 5−105 cells/ml was illuminated by the artificial light of blue and red spectrum altered for 1000 seconds of the dark-light cycle. The results showed a significant difference in the sensitivity of the algae chlorella sp. in producing dissolved oxygen which is 6.3 and 12.9 times higher than the chlorella kessleri for the blue and red light. While the photoperiodism response of Chlorella sp. has a time constant of 49.8 % for red and 37.5 % for blue smaller than Chlorella kessleri respectively. This result shows the algae chlorella sp. possesses good response characteristics to the red light, but less for photoperiodism response.