Real-time redox monitoring of a nitrosyl ruthenium complex acting as NO-donor agent in a single A549 cancer cell with multiplex Fourier-transform infrared microscopy

Multiplex Fourier-transform infrared microscopy (FT-IR) helped to monitor trans-{[}Ru(NO) (NH3)(4) (isn)](3+) (I), uptake by A549 lung carcinoma cell, as well as the generation of its product, nitric oxide (NO), inside the cell. Chronoamperometry with NO-sensor and FT-IR showed that exogenous NADH and the A549 cell induced the NO release redox mechanism. Chemical imaging confirmed that (I) was taken up by the cell, and that its localization coincided with its consumption in the cellular environment within 15 min of exposure. The Ru-NO absorption band in the IR spectrum shifted from 1932 cm(-1), when NO was coordinated to Ru as [Ru-II-NO+](3+), to 1876 cm(-1), due the formation of reduced species [Ru-II-NO0](2+), a precursor of NO release. Futhermore, the mu FT-IR spectral profile demonstrated that, as a result of the NO action on the target, NO interacted with nucleic acids, which provided a biochemical response that is detectable in living cells. (AU)