Objective To apply nitric oxide(NO) electrochemical microsensor in the real time detection of NO released from RAW 264 .3 cells infected by E .coli ,and to explore the application value of this NO microsensor in the research area of infection im‐munity against bacterium .Methods Taking NO microsensor to detect NO released from RAW 264 .3 cells respectively stimulated by E .coli of different densities and of 1 × 107 mL -1 for different time .Results The level of NO released from RAW 264 .3 cells was enhanced obviously when incubated with E .coli as compared with that of normal cells and the extent of incersase depended on the density of E .coli (P<0 .01) .The released level of NO increased gradually from the beginning and reached its peal at the time of 12 h then decreased slowly when incubated with E .coli of 1 × 107 mL -1 .Conclusion The electrochemical microsensor was applied in the real time detection of NO released from macrophages activated by E .coli successfully .

Objective To explore the performance of the novel nitric oxide(NO) electrochemical microsensor based on Au nano-particles(nano-Au) modified glass-fiber .Methods With columnar glass-fiber as the substrate material ,the in-situ chemical seed-growth technology was adopted to fabricate one kind of electrochemical microsensor based on gold nanoparticles pole electrodes and the amperometric response method was used to investigate the various properties of the NO microsensor .Results This microsensor had high sensitivity response to NO ,its linear range was 7 .2 nmol/L -11 .7μmol/L(r=0 .998) with a detection limit of 3 .6 nmol/L .Conclusion A novel electrochemical microsensor based on nano-Au pole electrode was fabricated .The NO microsensor posseses high sensitivity ,wide linear range ,good reproducibility and excellent anti-interference ability .