Sensitive spectrofluorimetric determination of cytochrome C with spirocyclic rhodamine B hydrazide in micellar medium.

A new spectrofluorimetric method for the determination of cytochrome c using spirocyclic rhodamine B hydrazide (RBH) as fluorogenic reagent in the presence of sodium dodecylbenzene sulfonate (SDBS) surfactant micelles was developed. The method was based on the reaction of cytochrome c with RBH, a colorless, nonfluorescent spirolactam of rhodamine B in SDBS micelles to give highly fluorescent rhodamine B and hence led to a large increase in fluorescence intensity. The dynamic range and detection limit for the determination of cytochrome c are 4.0-120 ng ml(-1) and 0.87 ng ml(-1) (3sigma), respectively. The optimal conditions for the detection of cytochrome c were evaluated and the possible detection mechanism was also discussed.