Photoluminescent microrods from the self-assembly of a biomimetic molecule: Application for the optical detection of pyrrole

Photoluminescent microrods were prepared through the self-assembly of N′1,N′6-bis(3-(1-pyrrolyl)propanoyl) hexanedihydrazide (DPH) in the presence of a photosensitizer and lanthanide ions. The photoluminescent microrods were applied as an optical sensor platform for the selective detection of pyrrole among other heterocyclic compounds. The production of photoluminescent microrods was simply achieved through the evaporation-induced self-assembly (EISA) process which incorporated photosensitive compounds with DPH microrods. The DPH microrods functioned as a host matrix for the photosensitive compounds and simultaneously worked as a photosensitizer enhancing photoluminescence (PL) from lanthanide ions. This photosensitizing function of the self-assembled microrods is unusual compared to other organic/inorganic self-assemblies that have been conventionally used only as a host matrix. The prepared photoluminescent microrods were exploited as an optical sensor platform allowing selective detection of pyrrole among several heterocyclic molecules through the PL quenching. The analyte pyrrole molecule quenched PL remarkably when it was associated with the photoluminescent microrods. The PL quenching showed a positive correlation with pyrrole concentration, conferring its performance as a quantitative sensor. In summary, the photoluminescent DPH microrods with multiple functions which can be prepared in a facile way of EISA are a promising optical sensor platform for the detection of an organic target molecule.