Fluorescent conjugated polymers

The dominant attribute that has driven interest in fluorescent conjugated polymers (CPs) sensory materials is their ability to produce signal gain in response to interactions with analytes. The increased sensitivity (amplification) is derived from the ability of a conjugated polymer to serve as a highly efficient transport medium of electronic excitation. Analyte specificity in CP-based sensors results from the covalent or physical integration of receptors, imprinting, and/or the CP s overall electrostatic and chemical characteristics. The observed amplification is a... 

Thomas SW III, Joly GD, Swager TM (2007) Chemical sensors based on amplifying fluorescent conjugated polymers. Chem Rev 107 1339-1386... 

Fan L-J, Zhanga Y, Murphy CB, Angell SE, Parker MFL, Flynn BR, Jones WE Jr (2009) Fluorescent conjugated polymer molecular wire chemosensors for transition metal ion recognition and signaling. Coord Chem Rev 253 401 122... 

Murphy CB, Zhang Y, Troxler T, Ferry V, Martin JJ, Jones WE Jr (2004) Probing Forster and Dexter energy-transfer mechanisms in fluorescent conjugated polymer chemosensors. J Phys Chem B 108 1537-1543... 

Kumaraswamy S, Bergstedt T, Sh X, Rininsland F, Kushon S, Xia W, Ley K, Achyuthan K, McBranch D, Whitten D (2004) Fluorescent-conjugated polymer superquenching facilitates highly sensitive detection of proteases. Proc Natl Acad Sci 101 7511-7515... 

Thomas SW, Swager TM (2006) Trace hydrazine detection with fluorescent conjugated polymers a tum-on sensory mechanism. Adv Mater 18 1047-1050... 

In another approach, a fluorescent conjugated polymer was used as the material for the preparation of a chemosensor to detect 2,4,6-trinitrotoluene (TNT) and its related nitroaromatic compounds. To this end, microparticles, made of three-dimensionally cross-linked poly(l,4-phenylene vinylene) (PPV) via emulsion polymerization, were synthesized [61]. This material was chosen due to its high fluorescence intensity and sensitivity to changes in its microenvironment. The chemosensor was exposed to vapour containing different amounts of TNT and quenching of the polymer luminescence at 560 nm was observed after excitation at 430 nm. The dependence of the fluorescence signal in response to the analyte was described by a modified Stem-Volmer equation that assumes the existence of two different cavity types. The authors proposed the modified Stem-Volmer equation as follows ... 

FIGURE 1.2 Basic structures of several fluorescent conjugated polymers. 

In conclusion, polymers play a versatile role in the field of chemosensors. Most interestingly, certain polymers can actively serve as sensors. This pertains to certain strongly fluorescent conjugated polymers, as pointed out above, and to polymers employed as cladding for optical fibers in evanescent wave-based sensors. Moreover, polymers are widely used as supports for transducers, which are either admixed or chemically linked to the polymer matrices. Typical examples are given in the following sections. 

Table 13.1 Six processable and fluorescent conjugated polymers covering the entire visible spectrum...

Huang, H., et al. 2004. Design of a modular-based fluorescent conjugated polymer for selective sensing. Angew Chem 43 5635. 

Thomas, S. W Joly, G. D. Swager, T. M. Chemical sensors based on amphfying fluorescent conjugated polymers. Chem. Rev. 2007,107,1339-1386. 

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