Phthalocyanine-based fluorescent chemosensor for the sensing of Zn (II) in dimethyl sulfoxide-acetonitrile

'Rough guide' evanescent wave optrode for colorimetric metalloporphyrine sensors

When films of zinc 5-(4-carboxyphenyl),10,15,20-triphenyl porphyrin (ZnTPP) are exposed to waterborne amine in pH- neutral or alkaline media, both Q- band and Soret band respond with a change of absorbance due to the donation of amine 'lone pair' electrons to the metalloprophyrin π orbital. However, this is difficult to reveal with a conventional spectrometer even under high amine concentration. We therefore introduce optical fibres coated with ZnTPP into a bespoke 'light balance' evanescent wave absorbance meter [doi:10.1016/j.snb.2016.05.065]. The light balance makes absorbance changes clearly visible under only 5μM aqueous amine, making PVC membranes redundant. We find sensitivity is higher, and limit- of- detection lower, in the Soret band rather than the Q- band, reflecting the stronger Soret band absorbance. Also, we find that sensitivity is higher, and limit- of- detection approximately two times lower, when rough rather than smooth fibres are used. We believe the rough fibre surface leads to enhanced evanescence, and therefore better overlap of the wave propagating in the fibre with the ZnTPP fibre cladding. We find a limit of detection to waterborne amines below 1μM, which compares well to other sensors for waterborne amines [Korent, S.M. et.al. Anal. Bioanal. Chem. 387 (2007) 2863-2870; Algarni, S. A. et.al. Talanta 153 (2016) 107-110]. We therefore recommend 'rough guide' evanescent wave optrodes, in combination with sensitive 'light balance' detector, to succeed membrane- embedding of colorimetric sensitisers such as metalloporphyrines.

Single Chemosensor for Double Analytes: Spectrophotometric Sensing of Cu(2+) and Fluorogenic Sensing of Al(3+) Under Aqueous Conditions

(E)-N-((8-Hydroxy-1,2,3,5,6,7-hexahydropyrido-[3,2,1-ij]-quinolin-9-yl)methylene)-4-tert-butyl -benzhydrazide has been developed as a single, dual-functional chemosensor. The chemosensor showed a good selectivity and sensitivity toward to Al(3+) and Cu(2+) at a low detection limit, respectively. Theoretical calculations have also been carried out to understand the configuration of the complexes.

A phthalocyanine-based fluorescent sensor for Zn2+ ion

This paper describes the preparation and spectral properties of a near-infrared fluorophore in which two bis(2-picolyl)amino moieties are axially linked to a silicon(IV) phthalocyanine core. The effects of various metal ions on its absorption and fluorescence spectra have been examined. The results indicate that this compound shows a high sensitivity and moderate selectivity toward Zn2+ ion.