Optical properties and sensor applications of Bimetallic porphyrins

MARIANA HAMER; J. PABLO TOMBA; IRENE REZZANO

SENSORS AND ACTUATORS B-CHEMICAL

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2014

0925-4005

tThe cationic Cu(II) and Fe(III) complexes of tetra(4-pyridyl)porphyrin [T4PyP]4+have been combined withthe anionic [H4TPPS]2−to obtain bimetallic J-aggregate nanostructures defined by the tendency to formthe FeIIIOCuIIbridge along with electrostatic interactions.The Resonant Raman spectra of the bimetallic structures revealed subtle but detectable changes of twosignificant bands: 661 cm−1(attributed to the out-of-plane bending of the Cu N bond) and 805 cm−1(sensitive to the nature of the axial ligand opposite to the oxo ligand), both indicating the important roleof the metallic centers in the formation of the CuFe nanorod aggregate.The sensing performance of the aggregates was explored monitoring the absorbance changes in thevisible region induced by adding different analytes (H2O2, NO2−, SO32−and N3−).The bimetallic nanostructures maintain the J-aggregation structure after successive addition of H2O2with an increasing absorption response at 435 cm−1(monomer band); this architecture was the mostsensitive arrangement confirming the synergic effect of the two metals.