Chemical sensitivity of self-assembled porphyrin nano-aggregates.
Nanostructured molecular assemblies may provide additional sensing properties not found in other arrangements of the same basic constituents. Among three-dimensional structures, nanotubes are particularly appealing for applications as chemical sensors, because of the potential inclusion of different guests inside the cavity or the induced modification of the skeletal interaction after analyte binding. Porphyrins are a class of compounds characterized by brilliant sensing properties, appearing also in non-ordered solid-state aggregates. In recent years, it was reported that aggregation of oppositely charged porphyrins led to the formation of self-assembled nanotubes and in this paper their sensing properties, both in solution and in the solid state, have been investigated. The interactions of porphyrin nanotubes with guest molecules have been monitored by following the changes in their UV-vis spectra. The results obtained have been exploited to build up a sensing platform based on a computer screen as a light source and a digital camera as detector. Porphyrin nanostructures exhibited an enhanced sensitivity to different compounds with respect to those shown by single porphyrin subunits. The reason for the increased sensitivity may be likely found in an additional sensing mechanism related to the modulation of the strength of the forces that keep the supramolecular ensemble together.
Department of Electronic Engineering, University of Rome Tor Vergata, Rome, Italy.
Francesca
F
Dini
Eugenio
E
Martinelli
Giuseppe
G
Pomarico
Roberto
R
Paolesse
Donato
D
Monti
Daniel
D
Filippini
Arnaldo
A
D'Amico
Ingemar
I
Lundström
Corrado
C
Di Natale
D003460:Crystallization / Q000379:methods*; D005740:Gases / Q000032:analysis* / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D011166:Porphyrins / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D013499:Surface Properties
D005740:Gases; D046911:Macromolecular Substances; D011166:Porphyrins