title: Reduced carbon dots versus oxidized carbon dots: photo- and electrochemiluminescence investigations for selected applications.
abstract: The study of the composition, morphology, and surface structure of carbon dots (Cdots) is critical to understanding their effect on the photo- and electrochemiluminescence (PL and ECL) of Cdots in selected applications. Herein, two kinds of Cdots were prepared with 3-(3,4-dihydroxyphenyl)-L-alanine (L-DOPA) as precursor. The Cdots prepared by using a carbonization-extraction strategy have a low oxidation level and are denoted as reduced Cdots (r-Cdots). The Cdots obtained with a carbonization-oxidation process are highly oxidized and are denoted as oxidized Cdots (o-Cdots). The o-Cdots have a carbon core and oxygen-containing loose shell, but the r-Cdots consist mainly of the carbon core. Whereas r-Cdots have a strong blue PL but no apparent ECL response, o-Cdots exhibit a relatively weak PL and strong ECL emission. These properties allow for selected applications of the Cdots. The r-Cdots were used in cell imaging with their high PL emission. The o-Cdots, with their high ECL efficiencies, were selected to sense Cu(2+) with Cu(2+) -inducing ECL quenching in the o-Cdots/K2 S2 O8 system. This work provides the possibility to control the composition of Cdots for selected applications and shows a good way to characterize surface traps of Cdots because ECL is characterized by the surface-state and PL is mainly related to the core-state in Cdots.
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, College of Chemistry, Nankai University, Tianjin, 300071, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Xu
authors.forename: Ming
authors.initials: M
authors.lastname: Wu
authors.forename: Xi-Zeng
authors.initials: XZ
authors.lastname: Feng
authors.forename: Xue-Bo
authors.initials: XB
authors.lastname: Yin
authors.forename: Xi-Wen
authors.initials: XW
authors.lastname: He
authors.forename: Yu-Kui
authors.initials: YK
authors.lastname: Zhang
mesh_terms: D002244:Carbon / Q000737:chemistry*; D003300:Copper / Q000032:analysis; D006367:HeLa Cells; D006801:Humans; D007980:Levodopa / Q000737:chemistry*; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry
chemical_list: D007980:Levodopa; D002244:Carbon; D003300:Copper; D010100:Oxygen