title: Visual detection of 2,4,6-trinitrotolune by molecularly imprinted colloidal array photonic crystal.
abstract: We developed a photonic crystal (PhC) sensor for the quantification of 2,4,6-trinitrotoluene (TNT) in solution. Monodisperse (210nm in diameter) molecularly imprinted colloidal particles (MICs) for TNT were prepared by the emulsion polymerization of methyl methacrylate and acrylamide in the presence of TNT as a template. The MICs were then self-assembled into close-packed opal PhC films. The adsorption capacity of the MICs for TNT was 64mg TNT/g. The diffraction from the PhC depended on the TNT concentration in a methanol/water (3/2, v/v) potassium dihydrogen phosphate buffer solution (pH=7.0, 30mM). The limit of detection (LOD) of the sensor was 1.03μg. The color of the molecularly imprinted colloidal array (MICA) changed from green to red with an 84nm diffraction red shift when the TNT concentration increased to 20mM. The sensor response time was 3min. The PhC sensor was selective for TNT compared to similar compounds such as 2,4,6-trinitrophenol, 2,4-dinitrotoluene, 2,6-dinitrotoluene, 2-nitromesitylene, 4-nitrotoluene, 2-nitrotoluene, 1,3-dinitrobenzene, methylbenzene, 4-nitrophenol, 2-nitroaniline, 3-aminophenol and 3-nitroaniline. The sensor showed high stability with little response change after three years storage. This sensor technology might be useful for the visual determination of TNT.
authors.affiliation: School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081, P.R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Lu
authors.affiliation: Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260, U.S.A.. Electronic address: asher@pitt.edu.
authors.forename: Sanford A
authors.initials: SA
authors.lastname: Asher
authors.affiliation: School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081, P.R. China. Electronic address: m_zihui@yahoo.com.
authors.forename: Zihui
authors.initials: Z
authors.lastname: Meng
authors.affiliation: School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081, P.R. China.
authors.forename: Zequn
authors.initials: Z
authors.lastname: Yan
authors.affiliation: School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081, P.R. China. Electronic address: minxue@bit.edu.cn.
authors.forename: Min
authors.initials: M
authors.lastname: Xue
authors.affiliation: School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081, P.R. China. Electronic address: qiulili@bit.edu.cn.
authors.forename: Lili
authors.initials: L
authors.lastname: Qiu
authors.affiliation: School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081, P.R. China.
authors.forename: Da
authors.initials: D
authors.lastname: Yi
keywords: 2,4,6-trinitrotoluene; Chemical sensor; Molecular imprinting technology; Photonic crystal; TNT visual detection