Photodynamic and Photothermal Effects of Carbon Dot-Coated Magnetite- and Porphyrin-Conjugated Confeito-Like Gold Nanoparticles

Abstract

Gold nanoparticles (AuNPs) possess the characteristics of both inertness and biocompatibility which enable great biomedical application in biosensors and drug delivery. Confeito-like AuNPs conjugated with porphyrin (TCPP) were synthesized and characterized to clarify the photodynamic and photothermal properties. The conjugation of TCPP was performed by covalent binding using L-cysteine or carbon dot-protected iron oxide (Fe3O4@Cdots) as adapted linkages. The product had a great aptitude for photosensitization performance and improved the efficiency of singlet oxygen generation, indicating the possible photodynamic properties in an order of AuNPs < Cdots < TCPP. TCPP could be best used for photodynamic application, and carbon dots and confeito-like AuNPs conjugated with TCPP could improve the effectiveness of photodynamic properties. Moreover, magnetite displayed excellent photothermal property better than that of AuNPs, while Cdots and TCPP do not contribute to the photothermal performance. Thus, this study confirmed that Fe3O4@Cdot-conjugated confeito-like AuNPs are available for both photodynamic and photothermal therapeutic application.

Hierarchical Composite Nanoarchitectonics with a Graphitic Core, Dendrimer and Fluorocarbon Domains, and a Poly(ethylene glycol) Shell as O2Reservoirs for Reactive Oxygen Species Production

“…The latter values calculated using eq increased in the order of Au nanoparticle (AuNP) < Fe 3 O 4 NP@carbon dot (Cdot) < AuNP/Fe 3 O 4 NP@Cdot < porphyrin derivative (TCPP) < AuNP/TCPP < AuNP/Fe 3 O 4 NP@Cdot/TCPP and with their concentration. Thus, the highest value (20 mmol/g­(material)) was obtained for AuNP/Fe 3 O 4 NP@Cdot/TCPP at a 10 μg/mL concentration . This value was smaller than the current CNH-based generators.…”

“…Moreover, the tendency for 1 O 2 production is in proportion to the O 2 uptake in carriers except for GO (Figure A). The 1 O 2 production capabilities have been reported for different generators using different detection techniques, such as UV–visible absorption spectroscopy, fluorescence, ,,− and electron paramagnetic resonance . Moreover, its quantitative evaluation depended on the evaluation technology.…”

“…Moreover, its quantitative evaluation depended on the evaluation technology. Then, singlet oxygen production was mainly expressed using singlet oxygen quantum yields ,− or using singlet oxygen generation values , obtained from fluorescence data. The latter values calculated using eq increased in the order of Au nanoparticle (AuNP) < Fe 3 O 4 NP@carbon dot (Cdot) < AuNP/Fe 3 O 4 NP@Cdot < porphyrin derivative (TCPP) < AuNP/TCPP < AuNP/Fe 3 O 4 NP@Cdot/TCPP and with their concentration.…”

“…The introduction of heteroatoms (oxygen or nitrogen) helps adjusting the chemical properties of CNHox for controlling its reactivity. Typical polymers used for hybridization are poly­(ethylene glycol) (PEG), sugar-based derivatives, and poly­(amido amine) (PAMAM) dendrimers . PAMAM dendrimers have a regularly branched three-dimensional (3D) spherical morphology with many voids that can host small molecules and abundant terminal functional groups that can help control the affinity for various materials.…”

Porphyrin Photoabsorption and Fluorescence Variation with Adsorptive Loading on Gold Nanoparticles

“…Imahori et al reported the fluorescence lifetime of porphyrin adsorbates on AuNPs was significantly longer than those on a two-dimensional Au substrate ( Imahori et al, 2001 ). The general strategy for the adjustment of photophysical properties of dye–AuNP conjugates involves altering the size and shape of the nanoparticles and the length of the linkers ( Imahori et al, 1998 ; Dulkeith et al, 2005 ; Hong and Li, 2013 ; Do and Imae, 2021 ). However, less attention has been paid to the number of adsorbates loaded per particle, despite the strong influence on photophysical properties ( Shinohara and Shinmori, 2016 ).…”