Photophysical and nonlinear optical characteristics of pyridyl substituted phthalocyanine - Detonation nanodiamond conjugated systems in solution

Diamond Nanoparticles-Porphyrin mTHPP Conjugate as Photosensitizing Platform: Cytotoxicity and Antibacterial Activity

“…Furthermore, it was also possible to observe the bands at 2921 and 3006 cm −1 which correspond to the mTHPP pyrrolic N-H. Similar results were obtained by Matshitse et al (2019) [40] who reported on the formation of conjugate system between detonation nanodiamond and ZnTPPcQ by a covalent bond. The conjugation by covalent bond was confirmed by FT-IR, wherein it was observed the shift of the band close to 1700 cm −1 (attributed to the stretching vibrational mode of the C=O bond of the carboxylic group present in the ND surface) to the region around of 1600 cm −1 , that could be associated with the presence of RCOOR, due to the formation of the covalent bond of the phthalocyanine hydroxyl group and the carboxyl groupd from ND.…”

“…Although noncovalent bonds have been widely used to couple bioactive molecules with ND [49][50][51][52], this method shows the disadvantage of low reproducibility and liability of the ND-molecule bond, which can be a result of nonhomogeneous ND surface chemistry combined with the low colloidal stability of ND. The surface functionalization of ND mainly with reactive carboxyl and hydroxyl groups brought the possibility of conjugation with a diversity of chemical groups or molecules (dyes, monomers, polymers, proteins, photosensitizers) [40,53,54], by covalent bond. Amongst the further chemical reaction that carboxylated ND can go through, the esterification outstands for providing increased colloidal stability of ND in aqueous suspension [40,[55][56][57].…”

“…The surface functionalization of ND mainly with reactive carboxyl and hydroxyl groups brought the possibility of conjugation with a diversity of chemical groups or molecules (dyes, monomers, polymers, proteins, photosensitizers) [40,53,54], by covalent bond. Amongst the further chemical reaction that carboxylated ND can go through, the esterification outstands for providing increased colloidal stability of ND in aqueous suspension [40,[55][56][57]. In this work, the nanoconjugate ND-mTHPP was obtained by an ester bond between carboxylated ND and mTHPP.…”

Photodynamic Antimicrobial Action of Asymmetrical Porphyrins Functionalized Silver-Detonation Nanodiamonds Nanoplatforms for the Suppression of Staphylococcus aureus Planktonic Cells and Biofilms

“…Firstly, an ester covalent bond between Ps and DNDs was formed according to a previously reported method ( Matshitse et al, 2019 ), taking advantage of the OH group on the Ps and the COOH from DNDs to result in Ps-DNDs nanohybrids ( Scheme 2 ). Briefly, DNDs (10 mg) were dissolved in 3 ml dry DMF and DCC (0.010 g, 0.049 mmol) was added separately to activate COOH groups on DNDs with continuous stirring for 48 h. Thereafter, respective Ps (10 mg each) and NHS (0.008 g, 0.07 mmol) as well as the bare AgNPs (5 mg) were subsequently added to the respective vessels and were allowed to react while stirring at room temperature for another 72 h. It is important to note that physical interactions will take place between AgNPs and nitrogen atoms on DNDs through Ag-nitrogen affinity.…”

Femtosecond Optical Nonlinearity of Nanodiamond Suspensions

“…Nonlinear absorption and nonlinear scattering have been found, depending on the nanodiamond particles size and concentration in suspensions [42][43][44]. It was also found that the functionalization of detonation nanodiamonds with other nanoparticles and complexes suitable for this purpose leads to a further decrease in the nonlinear transmittance coefficient [41,[45][46][47][48]. It has been also shown that aqueous suspensions of detonation nanodiamonds exhibit a saturable absorption (a short-term increase in the transmittance) under nanosecond [49] and femtosecond [50] excitations.…”