title: Graphene quantum dots/L-cysteine coreactant electrochemiluminescence system and its application in sensing lead(II) ions.
abstract: A new coreactant electrochemiluminescence (ECL) system including single-layer graphene quantum dots (GQDs) and L-cysteine (L-Cys) was found to be able to produce strong cathodic ECL signal. The ECL signal of GQD/L-Cys coreactant system was revealed to be mainly dependent on some key factors, including the oxidation of L-Cys, the presence of dissolved oxygen and the reduction of GQDs. Then, a possible ECL mechanism was proposed for the coreactant ECL system. Furthermore, the ECL signal of the GQD/L-Cys system was observed to be quenched by lead(II) ions (Pb(2+)). After optimization of some important experimental conditions, including concentrations of GQDs and L-Cys, potential scan rate, response time, and pH value, an ECL sensor was developed for the detection of Pb(2+). The new methodology can offer a rapid, reliable, and selective detection of Pb(2+) with a detection limit of 70 nM and a dynamic range from 100 nM to 10 μM.
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection Technology for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, and Department of Chemistry, Fuzhou University , Fujian 350108, China.
authors.forename: Yongqiang
authors.initials: Y
authors.lastname: Dong
authors.forename: Wanrong
authors.initials: W
authors.lastname: Tian
authors.forename: Shuyan
authors.initials: S
authors.lastname: Ren
authors.forename: Ruiping
authors.initials: R
authors.lastname: Dai
authors.forename: Yuwu
authors.initials: Y
authors.lastname: Chi
authors.forename: Guonan
authors.initials: G
authors.lastname: Chen