Covalently Conjugated Gold–Porphyrin Nanostructures

Abstract

Gold nanoparticles show important electronic and optical properties, owing to their size, shape, and electronic structures. Indeed, gold nanoparticles containing no more than 30–40 atoms are only luminescent, while nanometer-sized gold nanoparticles only show surface plasmon resonance. Therefore, it appears that gold nanoparticles can alternatively be luminescent or plasmonic and this represents a severe restriction for their use as optical material. The aim of our study was the fabrication of nanoscale assembly of Au nanoparticles with bi-functional porphyrin molecules that work as bridges between different gold nanoparticles. This functional architecture not only exhibits a strong surface plasmon, due to the Au nanoparticles, but also a strong luminescence signal due to porphyrin molecules, thus, behaving as an artificial organized plasmonic and fluorescent network. Mutual Au nanoparticles–porphyrin interactions tune the Au network size whose dimension can easily be read out, being the position of the surface plasmon resonance strongly indicative of this size. The present system can be used for all the applications requiring plasmonic and luminescent emitters.

Metal Complexes of the Porphyrin-Functionalized Polybenzoxazine

“…Porphyrin is a molecular material with many potential applications; for example, because of its unique magnetic, photophysical, and electronic properties, it has been integrated in light–energy conversion systems [ 42 , 43 , 44 , 45 ]. This colored macrocycle possesses particularly attractive photophysical properties, including very high extinction coefficients in the near-IR and visible regions where the solar photon flux occurs, making it useful in redox chemistry, photo-harvesting, semiconductors, and photoinduced electron transfer [ 46 , 47 ].…”

“…Various porphyrin-functionalized polymers have been prepared, usually connected with metal ions or reactive units [ 48 , 49 , 50 ]. Based on several previous reports [ 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ], in this study, the synthesis and ROP of a porphyrin-functionalized benzoxazine (Por-BZ) monomer were investigated; to the best of our knowledge, such structures have not been described previously.…”

Supramolecular Porphyrin Nanostructures Based on Coordination-Driven Self-Assembly and Their Visible Light Catalytic Degradation of Methylene Blue Dye

“…Therefore, the formation of well-defined, discrete (isolable) porphyrin nanostructures with a definite size, shape, and dimension is a challenging task. In the self-assembly of porphyrins, a variety of intermolecular non-covalent interactions (e.g., hydrogen bonding, ligand coordination, hydrophobic, π-π stacking, van der Waals forces, and electrostatic interactions) have been utilized [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. In recent years, Sn(IV) porphyrins have been widely used as a building block for the construction of useful porphyrin nanostructures, including nanocomposites, nanosheets, nanotubes, or thin stripes on surfaces [ 31 , 32 , 33 , 34 ].…”

Integrating Porphyrinic Metal-Organic Frameworks in Nanofibrous Carrier for Photodynamic Antimicrobial Application

“…The Q bands of TCPP were indicated that the Zr ions were not coordinated to the center of the porphyrin ligands [61]. In contrast, the Soret band of PCN−224 is significantly weaker and demonstrates a slight redshift, which may be due to ligand-to-metal charge transfer caused by the strong coordination of the TCPP linkers to the Zr-O clusters in the PCN−224 framework [62,63]. The photoluminescence (PL) spectra show two strong emission bands of PCN−224 NPs at about 658 nm and 721 nm under an excitation wavelength of 430 nm, which are typical emission peaks for the transition of porphyrins from S 1 →S 0 states, corresponding to Q (0-0) and Q (0-1) transitions, respectively (Figure S4) [64,65].…”

“…In addition, the PL spectrum underwent a similar change to the UV-Vis. This may be caused by the coordination of the TCPP ligand to the Zr6 cluster changing the molecular planarity in the porphyrin macrocycle and affecting the distribution of the porphyrin electron density [63,67].…”