Synthesis, Characterization, Spectroelectrochemical, Photophysical and HSA-Binding Properties of Novel and Versatile meso-Tetra(4-pyridylvinylphenyl)porphyrins Coordinated to Ruthenium(II)-Polypyridyl Derivatives

Author(s)

Viviane Viecelli ^[1] ; Otávio A. Chaves ^[2] ; Koiti Araki ^[3] ; Paulo R. Martins ^[4] ; Bernardo A. Iglesias ^[5]

Affiliation

^[1] Universidade Federal de Santa Maria. Departamento de Química. Laboratório de Bioinorgânica e Materiais Porfirínicos - Brasil

^[2] Instituto SENAI de Inovação em Química Verde - Brasil

^[3] Universidade de São Paulo. Instituto de Química - Brasil

^[4] Universidade Federal de Goiás. Instituto de Química - Brasil

^[5] Universidade Federal de Santa Maria. Departamento de Química. Laboratório de Bioinorgânica e Materiais Porfirínicos - Brasil

• Document type: Journal article
• Source: Journal of the Brazilian Chemical Society; v. 31, n. 11, p. 2282-2298, 2020-10-30.

Abstract

The free-base meso-tetra(4-pyridylvinylphenyl)porphyrin (1a) and its zinc(II) complex were synthesized and then functionalized with [Ru(bpy)2Cl]+ units (2a and 2b) via conventional methods and evaluated in terms of photophysical, electrochemical and biological aspects. All porphyrins present moderate singlet oxygen production and fluorescence quantum yield, and did not show any aggregation process. The photo-oxidation ability of those porphyrins decreased in the order 2b > 1a > 2a. The electrochemical behavior of 2a and 2b modified electrodes was evaluated by electroanalytical methods. Also the 2b electrode showed a smaller charge transfer resistance (36.70 Ω) when compared to 2a electrode (45.17 Ω). In addition, even after 30 consecutive injections of nitrite solution (1.0 × 10−4 mol L−1) using the flow injection analysis (FIA) system, the modified 2b electrode showed an relative standard deviation (RSD, n = 30) of 1.36% exhibiting a great potential as amperometric sensor for nitrite. Moreover, the biological evaluation towards human serum albumin (HSA) indicated spontaneous, weak and ground-state association in the IB subdomain (site III) and possibily a second site, changing the conventional interaction mode of porphyrins with biomolecules as consequence of the longer arms (porphyrin ring substituents at meso-positions) ending with a ruthenium polypyridyl complex, that may enhance the photodynamic therapy (PDT) efficiency of photogenerated reactive oxygen species (ROS) species. (AU)

• FAPESP's process: 18/21489-1 - Supramolecular nanotechnology: design, materials and devices
• Grantee: Henrique Eisi Toma
• Support Opportunities: Research Projects - Thematic Grants