In situ preparation of film and hydrogel bio-nanocomposites of chitosan/fluorescein-copper with catalytic activity

Saldías, César; Díaz, David Díaz; Bonardd, Sebastián; Soto-Marfull, Cristián; Córdoba, Alexander; Saldías, Soledad; Quezada, Caterina; Radić, Deodato; Leiva, Ángel

doi:10.1016/j.carbpol.2017.10.018

Cited by 27 publications

(10 citation statements)

References 79 publications

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“…The final concentration of fluorescein in the reaction medium was adjusted to eventually obtain an amine group:fluorescein ratio of 3:1. The reaction was kept in the dark at room temperature for 2 h. The obtained product was precipitated in tetrahydrofuran and then dried and washed several times with a Milli-Q water:methanol mixture (1:1) to remove the free fluorescein [37,38]. Finally, the PAMAM-fluorescein dendrimer was dried under vacuum and stored at 5 °C until further use.…”

Section: Methodsmentioning

confidence: 99%

Exploring the Effect of the Irradiation Time on Photosensitized Dendrimer-Based Nanoaggregates for Potential Applications in Light-Driven Water Photoreduction

et al. 2019

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Fourth generation polyamidoamine dendrimer (PAMAM, G4) modified with fluorescein units (F) at the periphery and Pt nanoparticles stabilized by L-ascorbate were prepared. These dendrimers modified with hydrophobic fluorescein were used to achieve self-assembling structures, giving rise to the formation of nanoaggregates in water. The photoactive fluorescein units were mainly used as photosensitizer units in the process of the catalytic photoreduction of water propitiated by light. Complementarily, Pt-ascorbate nanoparticles acted as the active sites to generate H2. Importantly, the study of the functional, optical, surface potential and morphological properties of the photosensitized dendrimer aggregates at different irradiation times allowed for insights to be gained into the behavior of these systems. Thus, the resultant photosensitized PAMAM-fluorescein (G4-F) nanoaggregates (NG) were conveniently applied to light-driven water photoreduction along with sodium L-ascorbate and methyl viologen as the sacrificial reagent and electron relay agent, respectively. Notably, these aggregates exhibited appropriate stability and catalytic activity over time for hydrogen production. Additionally, in order to propose a potential use of these types of systems, the in situ generated H2 was able to reduce a certain amount of methylene blue (MB). Finally, theoretical electronic analyses provided insights into the possible excited states of the fluorescein molecules that could intervene in the global mechanism of H2 generation.

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Section: Methodsmentioning

confidence: 99%

Exploring the Effect of the Irradiation Time on Photosensitized Dendrimer-Based Nanoaggregates for Potential Applications in Light-Driven Water Photoreduction

et al. 2019

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“…From the analysis of Figure 1 and data on metallic content achieved by AAE, it is clear that increasing the concentration of metallic salts the crosslinking level of CH grows up leading to formulations with hydrogel structure. The role of metallic salts to promote the biopolymeric crosslinking has been reported in open literature [28,29] …”

Section: Resultsmentioning

confidence: 99%

Chitosan‐Based Formulations Intended as Protective Spray for Mask Surfaces in Prevention of Coronavirus Dissemination

et al. 2022

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The extraordinary occurrence of COVID-19 by the fast expansion of viral infections has propelled particular interest in developing novel antiviral and virucidal agents to guarantee personal security. The main objective of this work is to propose novel formulations able to optimize the use of personal protection elements. In recent years, chitosan (CH) has attracted attention for being an interesting multifunctional, biodegradable, non-antigenic, non-toxic, and biocompatible natural polymer with antimicrobial properties. In this work, formulations based on a CH matrix containing silver, and Copper based nanoparticles have been developed. The novelty of this proposal is that almost liquid formulations have been reached, possessing verified properties to inhibit evolved virus such as herpes simplex type 1 (HSV-1) and bovine betacoronavirus (BCoV), the latter belonging to the same family of the wellknown the well-known SARS-CoV-2. Besides antibacterial bioactivity; as well as the ability of these formulations to be easily sprayed on various surfaces, including conventional face masks, have been verified and discussed. The results presented in this contribution provide strong evidence on CH films as an ideal biosafe surface-protective for several daily used materials including the conventional face masks.

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“…In the same year, a simple procedure was reported for the synthesis of Cu NPs in a chitosan/fluorescein (CS/F) hydrogel and film matrix by immersing the particular matrix in an aqueous medium comprised of a metallic salt precursor and reducing agent under an N 2 atmosphere at 75 °C for 3 h ( Scheme 8 ). 88 The high catalytic yield of the prepared nanocomposites was demonstrated by reducing methylene blue using N 2 H 4 as a reducing agent. According to the experimental results, the order of the degradation reaction of the MB–N 2 H 4 system and catalytic activity were strongly dependent on the type of nanocomposite used.…”

Section: Catalytic Applications Of Synthesized Palladium- and Copper-...mentioning

confidence: 99%

Recent developments in hydrogels containing copper and palladium for the catalytic reduction/degradation of organic pollutants

2022

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In situ preparation of film and hydrogel bio-nanocomposites of chitosan/fluorescein-copper with catalytic activity

Cited by 27 publications

References 79 publications

Exploring the Effect of the Irradiation Time on Photosensitized Dendrimer-Based Nanoaggregates for Potential Applications in Light-Driven Water Photoreduction

Exploring the Effect of the Irradiation Time on Photosensitized Dendrimer-Based Nanoaggregates for Potential Applications in Light-Driven Water Photoreduction

Chitosan‐Based Formulations Intended as Protective Spray for Mask Surfaces in Prevention of Coronavirus Dissemination

Recent developments in hydrogels containing copper and palladium for the catalytic reduction/degradation of organic pollutants

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