Optimization of a microchip electrophoresis method with electrochemical detection for the determination of nitrite in macrophage cells as an indicator of nitric oxide production
journal contributionposted on 07.03.2019 by Joseph M. Siegel, Kelci M. Schilly, Manjula B. Wijesinghe, Giuseppe Caruso, Claudia G. Fresta, Susan M. Lunte
Any type of content formally published in an academic journal, usually following a peer-review process.
A ME-EC method that uses transient isotachophoresis and a Pt black-modifed working electrode to enhance the signal and detect nitrite as well as other electrochemically active species was reported. First, a stacking method to enhance the signal of nitrite through the addition of NaCl to the run buﬀer was developed that provided a 5.2-fold decrease in the LOD for nitrite. Then, a procedure to modify a Pt working electrode with Pt black for the detection of nitrite was optimized. This electrode modification was then coupled with a ME-EC method, and a signal enhancement for nitrite, hydrogen peroxide, and ascorbic acid was obtained. The use of a Pt black-modified working electrode resulted in an increased sensitivity for nitrite. This method was then used to detect nitrite as an indicator of NO production in a bulk cell lysate sample. The incorporation of the tITP system and Pt black-modified working electrode improved the method previously reported by our group by increasing the sensitivity and decreasing the LOD.