Sensitive detection of superoxide anion released from living cells using silver nanoparticles and functionalized multiwalled carbon nanotube composite

Considering the crucial roles of superoxide anion (O-2(center dot-)) in pathological conditions, it is of great urgency to establish a reliable approach for real-time determination of O-2(center dot-). Herein, a sensitive non-enzymatic sensor was constructed based on silver nanoparticles (AgNPs) and sodium dodecyl sulfate functionalized carbon nanotubes (SDS-MWCNTs) composites to measure the release of O-2(center dot-) from living cells. As an analytical and sensing platform, the AgNPs/SDS-MWCNTs modified glassy carbon electrode exhibited excellent electrochemical performance toward O-2(center dot-) with a determination limit as low as 0.0897 nM and wide linear range of 6 orders of magnitude, which was superior to other O-2(center dot-) electrochemical sensors. The excellent performance was attributed to the SDS-MWCNTs composites being used as effective load matrix for the deposition of AgNPs. Importantly, this novel non -enzymatic sensor could be applied to determination of Of-released from living cells, and the amount of flux of O-2(center dot-) increased accordingly with the improving of the concentration of AA, which has the possibility of application in clinical diagnostics to assess oxidative stress of living cells. (C) 2017 Elsevier B.V. All rights reserved.