title: Reusable sensor based on functionalized carbon dots for the detection of silver nanoparticles in cosmetics via inner filter effect.
abstract: We report a low cost selective analytical method based on inner filter effect (IFE) for citrate-silver nanoparticle (cit-AgNP) detection, in which fluorescent amine-derivatized carbon dots (a-CDs) act as the donor and aggregated cit-AgNPs as the energy receptor. Carbon dots (CDs) were chemically modified with ethylenediamine (EDA) moieties via amidic linkage displaying an emission band at 440nm. The presence of cit-AgNPs produces a remarkably quenching of a-CD fluorescence via IFE, since the free amine groups at CD surface induce the aggregation of cit-AgNPs accompany by a red-shifting of their characteristic plasmon absorption wavelength, which resulted in "turn-on" of the IFE-decreased in CD fluorescence. The proposed method, which involves the use of chelating agents for removal of metal ions interferences, exhibits a good linear correlation for detection of cit-AgNPs from 1.23×10(-5) to 6.19×10(-5) mol L(-1), with limits of detection (LOD) and quantification (LOQ) of 5.17×10(-6) and 1.72×10(-5) mol L(-1,) respectively. This method demonstrates to be efficient and selective for the determination of cit-AgNPs in complex matrices such as cosmetic creams and reveals many advantages such as low cost, reusability, high sensitivity and non time-consuming compared with other traditional methods.
authors.affiliation: Department of Analytical Chemistry, Marie Curie Building, Campus de Rabanales, University of Córdoba, E-14071 Córdoba, Spain.
authors.forename: Angelina
authors.initials: A
authors.lastname: Cayuela
authors.affiliation: Department of Analytical Chemistry, Marie Curie Building, Campus de Rabanales, University of Córdoba, E-14071 Córdoba, Spain.
authors.forename: M Laura
authors.initials: ML
authors.lastname: Soriano
authors.affiliation: Department of Analytical Chemistry, Marie Curie Building, Campus de Rabanales, University of Córdoba, E-14071 Córdoba, Spain. Electronic address: qa1vacam@uco.es.
authors.forename: Miguel
authors.initials: M
authors.lastname: Valcárcel
keywords: Carbon dots; Cosmetic cream; Fluorescent nanosensor; Functionalization; Inner filter effect; Silver nanoparticles