Objective: To develop an Optical Nitric Oxide Biosensor and investigate the activities of drugs that stimulate macrophage to produce nitric oxide.
Methods: An NO biosensor was built on Cyt C which had been immobilized by Al2O3/SiO2 sol-gel procedure. Then the biosensor's characteristics in response to nitric oxide were studied by UV. The detection of NO in the culture solution that contained drugs (sulfated polysaccharides, Lentinan, Mannatide) was carried out by using interferon-gamma (IFN-gamma) and lipopolysaccharide (LPS) as positive control.
Results: The standard curve was linear within the range of 20. 0-180.0 micromol/L of NO in acidified culture solution (r = 0.9959). The limit of detection was 5.0 micromol/L; within-day precision was 3.5%; day-to-day precision was 7.9%. The concentrations of NO in culture solutions were (12.24+/-3.39) micromol/L, (8.51 +/- 0.19) micromol/L and (8.23 +/- 0.26) micromol/L, which were compared with the use of Griess method, and no statistically significant difference was observed.
Conclusion: The biosensor can be used as a semi-quantitative analysis method and be used for screening drugs preliminarily.