Electrochemistry and electrochemiluminescence of resorufin dye: Synergetic reductive-oxidation boosted by hydrogen peroxide. (20th December 2022) - Seo, Young Hun
Highlights: The reversible reduction peak of resorufin produces a stable cathodic ECL. The ECL signal is amplified by a dual co-reactant including K2 S2 O8 and H2 O2 . It shows a linear ECL response in the 0–150 μM range of H2 O2 with a LOD 6.8 μM. Abstract: To develop robust field diagnostic systems capable of responding to medical needs, miniaturization of devices and high target sensitivity remain significant challenges. Electrochemiluminescence (ECL) is an ideal analysis tool to meet these challenges, and developing novel ECL materials is essential. Here we report the reversible electrochemical properties of resorufin, a commercial fluorescent dye, and its highly stable cathodic ECL. We find the cathodic ECL emission from the resorufin quantitatively changes upon the H2 O2 content and propose the selective ECL molecular sensor against it. Resorufin undergoes reversible two-electron-transfer electrochemical reduction, and it generates cathodic ECL via a reductive-oxidation pathway with the S2 O8 2− co-reactant. Interestingly, highly enhanced, synergetic ECL is produced in the dual K2 S2 O8 –H2 O2 co-reactant system, and especially, it can be used for selective molecular recognition of H2 O2 . Via the chronoamperometric application, the resorufin ECL signal reveals the linear correlation with the H2 O2 concentration range of 0–150 µM with a detection limit of 6.8 µM. Resorufin exhibits strong potential as a new ECL luminophore. Also, selective enhancement of ECL suggests potential applicability to various immunoassays using H2 O2 .