The Influence of the Nature of the Polymer Incorporating the Same A3B Multifunctional Porphyrin on the Optical or Electrical Capacity to Recognize Procaine

Abstract

The multifunctionality of an A3B mixed-substituted porphyrin, namely 5-(4-carboxyphenyl)-10,15,20-tris(4-methylphenyl)porphyrin (5-COOH-3MPP), was proven due to its capacity to detect procaine by different methods, depending on the polymer matrix in which it is incorporated. The hybrid nanomaterial containing k-carrageenan and AuNPs (5-COOH-3MPP-k-carrageenan-AuNPs) was able to optically detect procaine in the concentration range from 5.76 × 10−6 M to 2.75 × 10−7 M, with a limit of detection (LOD) of 1.33 × 10−7 M. This method for the detection of procaine gave complementary results to the potentiometric one, which uses 5-COOH-3MPP as an electroactive material incorporated in a polyvinylchloride (PVC) membrane plasticized with o-NPOE. The detected concentration range by this ion-selective membrane electrode is wider (enlarged in the field of higher concentrations from 10−2 to 10−6 M), linearly dependent with a 53.88 mV/decade slope, possesses a detection limit of 7 × 10−7 M, a response time of 60 s, and has a certified stability for a working period of six weeks.

Nanomaterials Based on 2,7,12,17-Tetra-tert-butyl-5,10,15,20-tetraaza-21H,23H-porphine Exhibiting Bifunctional Sensitivity for Monitoring Chloramphenicol and Co2+

“…The five isosbestic points that are displayed on the UV-Vis spectra (at 375 nm, 535 nm, 566 nm, 612 nm, and 630 nm) demonstrate the existence of some intermediate species between the AuNPs and azaporphyrin that affect the entire macrocycle. The synergistic effect between AuNPs and porphyrins generally provides an enlarged absorption domain [62][63][64] that is useful for improving optical applications. In the formed complex, the gold nanoparticles that are negatively surface charged easily interact with the partially positively charged nitrogen atoms of the porphyrin core in the porphyrin base, or with the diprotonated porphyrin that forms in the acid medium.…”