Rational Design of a Nile Red/Polymer Composite Film for Fluorescence Sensing of Organophosphonate Vapors Using Hydrogen Bond Acidic Polymers

Abstract

The solvatochromic dye Nile Red dispersed in selected hydrogen bond acidic polymer matrixes demonstrated strong fluorescence enhancement at the presence of dimethyl methylphosphonate (DMMP) vapors. Two hydrogen bond acidic polymers were examined as dye matrixes, one with fluorinated alcohol groups on a polystyrene backbone (PSFA) and the other with fluorinated bisphenol groups alternating with oligo(dimethylsiloxane) segments (BSP3). The combination of hydrogen bond acidic polymer (a strong sorbent for DMMP) with the solvatochromic dye led to initial depression of the dye fluorescence and a significant red shift in the absorbance and fluorescence spectra. DMMP sorption changed the dye environment and dramatically altered the fluorescence spectrum and intensity, resulting in a strong fluorescence enhancement. It is proposed that this fluorescence enhancement is due to the competition set up between the dye and the sorbed vapor for polymeric hydrogen-bonding sites. The highest responses were obtained with BSP3. DMMP detection has been demonstrated at sub-ppm DMMP concentrations, indicating very low detection limits compared to previous Nile Red/polymer matrix fluorescence vapor sensors. Nile Red/poly(methyl methacrylate) films prepared for comparisons exhibited substantially lower response to DMMP. Rational selection of polymers providing high sorption for DMMP and competition for hydrogen-bonding interactions with Nile Red yielded flourescent films with high sensitivity.

A study of PVDF Langmuir‐Blodgett thin film using quartz crystal microbalance

“…Since the vapor pressure of DMMP at 258C is 112 Pa, 10 it exists as a low-volatility liquid at room temperature. Different concentrations of DMMP vapor were obtained by multiple dilutions.…”

Origin and role of elasticity in the enhanced DMMP detection by ZnO/SAW sensor

“…An ideal chemical agent simulant would mimic all relevant chemical and physical properties of the CWA without its associated toxicological properties. Few articles were reported in literature related to the detection of DMMP using SAW sensors [7][8][9][10]. Recently diamond nanoparticles dispersed on SAW devices were used for the detection of DMMP vapors [7].…”

Detection of nerve agent hydrolytes in an engineered nanopore

“…Thus far, numerous techniques have been developed for the detection of these nerve agents, as well as their degradation products and simulants. These include gas chromatography [3], liquid chromatography [4], ion chromatography [5], capillary electrophoresis [6], gas chromatography-mass spectrometry [7,8], liquid chromatographymass spectrometry [9], quartz-crystal microbalance [10], surface acoustic wave [11,12], metal oxide semiconductor [13,14], functionalized liquid crystal [15], microcantilever [16], interferometry [17], enzymatic assays [18][19][20], molecularly imprinted polymers [21], colorimetric method [22], fluorescent detection [23,24], electrochemical analysis [25,26], sensor array [27,28], and lab-on-chip technique [29]. However, the technology currently available is certainly not compatible with our needs in terms of sensitivity, selectivity, portability, low cost, ease of use, and rapid response [21,30].…”