Ferrocyanide-ferricyanide redox couple induced electrochemiluminescence amplification of carbon dots for ultrasensitive sensing of glutathione
writer：Wen-Jun Niu, Rong-Hui Zhu, Serge Cosnier, Xueji Zhang, and Dan Shan*
keywords：Carbon dots; Amphiphilic pyrrole derivative; Ferrocyanide-ferricyanide redox system; Electrochemiluminescence; Glutathione
source：期刊
specific source：Analytical Chemistry
Issue time：2015年
Here we report a novel solid-state ECL sensor for ultrasensitive sensing of glutathione (GSH) based on ferrocyanide-ferricyanide redox couple (Fe(CN)63?/4?) induced electrochemiluminescence (ECL) amplification of carbon dots (C-dots). The electropolymerization of C-dots and (11-Pyrrolyl-1-yl-undecyl) triethylammonium tetrafluoroborate (A2) enabled immobilization of the hydrophilic C-dots on the surface of glassy carbon electrode (GCE) perfectly, while the excellent conductivity of polypyrrole was exploited to accelerate electron transfer between them. The Fe(CN)63?/4? can expeditiously convert the C-dots and S2O82? to C-dot?? and SO4??, respectively. High yields of the excited state C-dots (C-dots*) were obtained and a ~10-fold ECL amplification was realized. The C-dots* obtained through the recombination of electron-injected and hole-injected processes may be impeded due to the interference of GSH to K2S2O8. Therefore, the constructed sensor for GSH showed a detection limit down to 54.3 nM (S/N = 3) and a wide linear range from 0.1~1.0 mM with a correlation coefficient of 0.997.