Abstract: The authors have prepared amino-functionalized carbon dots (AC-dots) and applied them to fluorescently label a molecularly imprinted polymer (MIP) prepared by using 2,4-dinitrotoluene (DNT) as a template. Since DNT can retard vinyl polymerization, poly(methyl acrylate-co-acrylic acid) was used as a monomer. Non-imprinted polymers (NIPs) were also synthesized in order to compare data. As expected, MIPs exhibit higher adsorption than NIPs, with imprinting efficiencies ranging from 2 to 2.5. DNT is specifically captured by the cavities in the MIP and interact with AC-dots on the surface, resulting in quenching of the fluorescence of the AC-dots. Response to DNT reaches equilibrium within ~30 min. The method has a dynamic range that extends from 1 to 15 ppm, and allows for quantitation of DNT in aqueous solutions, with a detection limit of 0.28 ppm. Selectivity tests conducted in presence of DNT analogs demonstrated the selective recognition of DNT
Template and target information: 2,4-dinitrotoluene, DNT
Author keywords: surface modification, Quenching, Fluorometry, Stern-Volmer plot, Poly(methyl acrylate-co-acrylic acid), Silica colloidal crystal, nitroaromatic compounds