P2.3.4 Metalloporphyrin and pH Indicator Blends to Enhance Sensitivity of Optical Chemosensors

14th International Meeting on Chemical Sensors - IMCS 2012
2012-05-20 - 2012-05-23
Nürnberg/Nuremberg, Germany
P2.3 Sensors Based on Optical Techniques
F. Dini, G. Magna, G. Di Biccari, E. Martinelli, C. Di Natale - Dept. of Electronic Engineering, University of Rome Tor Vergata (Italy), G. Pomarico, R. Paolesse - Dept. of Chemical Science and Technology, University of Rome Tor Vergata (Italy), I. Lundström - Division of Applied Physics, Dep. of Physics, Chemistry and Biology, Linköping University (Sweden)
1458 - 1461


Labeling of optically inert receptors with sensitive dyes is a popular technique used for the development of optochemical sensors. The bond with an analyte perturbs the interaction between the single components and causes a detectable change in optical features. In this paper, such strategy is further extended preparing blends of two chemoresponsive dyes: a metalloporphyrin and an acid/base indicator. Here, both the constituents can change color upon the interaction with volatile compounds, but some target molecules engage chemical interactions so weak that does not involve changes in the optical spectrum. Our results demonstrate that dye blends show an enhancement of the sensing capabilities compared with those of the basic constituents. Furthermore, the measure of compounds not detectable by the single constituents becomes possible, and the range of class of compounds that can be detected is enlarged. The mixture provides a response pattern not correlated to that of single components, hence this strategy may allow for the preparation of arrays with a wider number of crossselective colorimetric spots.