title: Label-free fluorimetric detection of CEA using carbon dots derived from tomato juice.
abstract: A facile-green strategy to synthesize carbon dots (CDs) with a quantum yield (QY) of nearly 13.9% has been built up, while tomato juice served as the carbon source. Interestingly, not only the precursor of CDs and the whole synthesis procedure were environmental-friendly, but this type of CDs also exhibited multiple advantages including high fluorescent QY, excellent photostability, non-toxicity and satisfactory stability. Significantly, a label-free sensitive assay for detecting carcinoembryonic antigen (CEA) in a continuous and recyclable way has been proposed on the basis of adsorption and desorption of aptamers by the surface of CDs through a competitive mechanism. To be specific, the richness of carboxyl groups of the CDs enabled strong adsorption of ssDNA to the surface of CDs through π-π stacking interactions, resulting in the effective fluorescence quenching by forming CDs-aptamer complexes. The stronger binding affinity between CEA and CEA-aptamer than the π-π stacking interactions has been taken advantage to achieve immediate recovery of the fluorescence of CDs once CEA was introduced. Thereby, quantitative evaluation of CEA concentration in a broad range from 1ngmL(-1) to 0.5ngmL(-1) with the detection limit of 0.3ngmL(-1) was realized in this way. This strategy can be applied in a recyclable way, broadening the sensing application of CDs with biocompatibility. Besides, the CDs were used for cell imaging, potentiating them towards diverse purposes.
authors.affiliation: College of Pharmaceutical Sciences, Engineer Research Center of Chongqing Pharmaceutical Process and Quality Control, Southwest University, Chongqing 400715, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Miao
authors.affiliation: College of Pharmaceutical Sciences, Engineer Research Center of Chongqing Pharmaceutical Process and Quality Control, Southwest University, Chongqing 400715, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Wang
authors.affiliation: College of Pharmaceutical Sciences, Engineer Research Center of Chongqing Pharmaceutical Process and Quality Control, Southwest University, Chongqing 400715, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhuo
authors.affiliation: Department of Medicine and Cardiovascular Institute, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA.
authors.forename: Zinan
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: College of Pharmaceutical Sciences, Engineer Research Center of Chongqing Pharmaceutical Process and Quality Control, Southwest University, Chongqing 400715, China. Electronic address: ming4444@swu.edu.cn.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Yang
mesh_terms: D065966:Absorption, Physicochemical; D002244:Carbon / Q000737:chemistry*; D002272:Carcinoembryonic Antigen / Q000032:analysis*; D005456:Fluorescent Dyes / Q000138:chemical synthesis; D000067030:Fruit and Vegetable Juices; D018551:Solanum lycopersicum / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013194:Staining and Labeling
chemical_list: D002272:Carcinoembryonic Antigen; D005456:Fluorescent Dyes; D002244:Carbon
keywords: Assaying; CEA; Carbon dots; Photoinduced electron transfer