title: Dual-peak electrogenerated chemiluminescence of carbon dots for iron ions detection.
abstract: Carbon dots (CDs) have rigorously been investigated on their unique fluorescent properties but rarely their electrogenerated chemiluminescence (ECL) behavior. We are here to report a dual-peak ECL system of CDs, one at -2.84 V (ECL-1) and the other at -1.71 V (ECL-2) during the cyclic sweep between -3.0 and 3.0 V at scan rate of 0.2 V s(-1) in 0.1 M tetrabutyl ammonium bromide (TBAB) ethanol solution, which is more efficiency to distinguish metallic ions than single-peak ECL. The electron transfer reaction between individual electrochemically reduced nanocrystal species and coreactants led to ECL-1, in which the electron injected to the conduction band of CDs in the cathodic process. Ion annihilation reactions induced direct formation of exciplexes that produced another ECL signal, ECL-2. ECL-1 showed higher sensitivity to the surrounding environment than ECL-2 and thus was used for ECL detection of metallic ions. Herein, we can serve as an internal standard method to detect iron ions. A linear relationship of the intensity ratio R of ECL-1 and ECL-2 to iron ions was observed in the concentration extending from 5 × 10(-6) to 8 × 10(-5) M with a detection limit of 7 × 10(-7) M.
authors.affiliation: Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University , Xi'an 710062, P. R. China.
authors.forename: Pengjia
authors.initials: P
authors.lastname: Zhang
authors.forename: Zhenjie
authors.initials: Z
authors.lastname: Xue
authors.forename: Dan
authors.initials: D
authors.lastname: Luo
authors.forename: Wei
authors.initials: W
authors.lastname: Yu
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Guo
authors.forename: Tie
authors.initials: T
authors.lastname: Wang