A dissolved oxygen sensor based on composite fluorinated xerogel doped with platinum porphyrin dye

A new functional fluorinated material taking n-propyltrimethoxysilicane (n-propyl-TriMOS) and 3,3,3-trifluoropropyltrimethoxysilicane (TFP-TriMOS) as precursors was applied to construct a novel dissolved oxygen sensing film. The sensing film was fabricated by dip-coating the functional fluorinated material-doped [meso-tetrakis(pentafluorophenyl) porphyinato] platinum(II) (PtF(20)TPP) onto a glass slide. The oxygen sensing film exhibited a good linear relationship, fast response time, long stability and high sensitivity to dissolved oxygen. In the developed optical oxygen sensor, an LED and a photodiode were composed to construct a back-detection optical system not needing an optical fiber based on fluorescence intensity detection. The smart optical oxygen sensor based on the PtF(20)TPP fluorescence quenching possesses the advantages of portability and low cost and can be applied to the dissolved oxygen in situ monitoring in seawater. Copyright (C) 2009 John Wiley & Sons, Ltd.National Science and Technology Development Project (863 project)[2006AA09Z160]; National Natural Scientific Foundation of China[20775064

Rhodamine-based ratiometric fluorescence sensing for the detection of mercury(II) in aqueous solution

Novel ratiometric fluorescent silica nanoparticles with high selectivity towards Hg2+ were synthesized for the detection of Hg2+, Hg2+ promoted the ring opening of spirolactam in the rhodamine moiety grafted onto the silica nanoparticles, resulting in a change in the fluorescence intensity. The fluorescence intensity was proportional to the Hg2+ concentration, and the detection limit (S/N = 3) for Hg2+ was found to be 2.59 x 10(-9) mol L-1 with a linear range from 0.4 to 8 x 10(-7) mol L-1. In addition, the morphology of the silica nanoparticles, the effects of pH and co-existing substances, and the reversibility were investigated. The proposed approach was successfully applied to the determination of Hg2+ in water samples. (C) 2010 Elsevier B.V. All rights reserved.National Nature Scientific Foundation of China (NSFC) [20775064, 20735002]; National Basic Research Program of China [2010CB732402