{"title":"Tunable photoluminescence of electrosynthesized Ag2S@ZnSe quantum dots for nanomedicine applications","authors":"","doi":"10.1016/j.nanoso.2024.101400","DOIUrl":null,"url":null,"abstract":"<div><div>Quantum dots (QDs) synthesized from environmentally friendly precursors associated to scalable and high-efficiency production routes are essential for nanomedicine applications. Ag<sub>2</sub>S nanocrystal is notable by antimicrobial activity, photothermal properties, and low toxicity, making it promising bioactive nanomaterial. In this work, L-glutathione (GSH) capped Ag<sub>2</sub>S and ZnSe seeds were synthesized by using a fast and environmentally friendly electrochemical method (cavity cell, graphite powder macroelectrode and aqueous medium) and tested for biological applications. Ag<sub>2</sub>S nanocrystals presented a monoclinic structure (XRD analysis). The modulation of the optical properties was carried out by varying the Ag<sup>+</sup>/S<sup>2-</sup> ratio (1:1, 2:1, and 4:1), showing a photoluminescence hypsochromic shift from 916 to 759 nm, respectively. The modulation of the optical parameters was also carried out by the synthesis of Ag<sub>2</sub>S@ZnSe core/shell nanostructures. ZnSe seeds were prepared by the same electrochemical method and added to the Ag<sub>2</sub>S solution followed by thermal treatment under reflux (10 min). Ag<sub>2</sub>S@ZnSe systems showed higher photoluminescence intensity and a hypsochromic shift of the emission band using Ag<sub>2</sub>S cores (Ag<sup>+</sup>/S<sup>2-</sup> = 1:1 and 1:2), which was associated to the formation of alloy-type structures. In the case of the Ag<sub>2</sub>S@ZnSe (Ag<sup>+</sup>/S<sup>2-</sup> = 1:4), a bathochromic shift of the emission bands can be observed, which was associated to the formation of a core/shell structure. Ag<sub>2</sub>S@ZnSe QDs were tested in antimicrobial and cytotoxicity assays, showing a minimal inhibitory concentration (MIC) equal to 512 µg.mL<sup>−1</sup>. No cytotoxicity was observed against the Vero cell line at all concentrations tested (7.81–1000 µg.mL<sup>−1</sup>), and low cytotoxicity against the HT-29 tumor line (7.81–31.25 µg.mL<sup>−1</sup>), thus showing promising results for bioapplications.</div></div>","PeriodicalId":397,"journal":{"name":"Nano-Structures & Nano-Objects","volume":null,"pages":null},"PeriodicalIF":5.4500,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nano-Structures & Nano-Objects","FirstCategoryId":"1","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2352507X24003123","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Physics and Astronomy","Score":null,"Total":0}
引用次数: 0
Abstract
Quantum dots (QDs) synthesized from environmentally friendly precursors associated to scalable and high-efficiency production routes are essential for nanomedicine applications. Ag2S nanocrystal is notable by antimicrobial activity, photothermal properties, and low toxicity, making it promising bioactive nanomaterial. In this work, L-glutathione (GSH) capped Ag2S and ZnSe seeds were synthesized by using a fast and environmentally friendly electrochemical method (cavity cell, graphite powder macroelectrode and aqueous medium) and tested for biological applications. Ag2S nanocrystals presented a monoclinic structure (XRD analysis). The modulation of the optical properties was carried out by varying the Ag+/S2- ratio (1:1, 2:1, and 4:1), showing a photoluminescence hypsochromic shift from 916 to 759 nm, respectively. The modulation of the optical parameters was also carried out by the synthesis of Ag2S@ZnSe core/shell nanostructures. ZnSe seeds were prepared by the same electrochemical method and added to the Ag2S solution followed by thermal treatment under reflux (10 min). Ag2S@ZnSe systems showed higher photoluminescence intensity and a hypsochromic shift of the emission band using Ag2S cores (Ag+/S2- = 1:1 and 1:2), which was associated to the formation of alloy-type structures. In the case of the Ag2S@ZnSe (Ag+/S2- = 1:4), a bathochromic shift of the emission bands can be observed, which was associated to the formation of a core/shell structure. Ag2S@ZnSe QDs were tested in antimicrobial and cytotoxicity assays, showing a minimal inhibitory concentration (MIC) equal to 512 µg.mL−1. No cytotoxicity was observed against the Vero cell line at all concentrations tested (7.81–1000 µg.mL−1), and low cytotoxicity against the HT-29 tumor line (7.81–31.25 µg.mL−1), thus showing promising results for bioapplications.
期刊介绍:
Nano-Structures & Nano-Objects is a new journal devoted to all aspects of the synthesis and the properties of this new flourishing domain. The journal is devoted to novel architectures at the nano-level with an emphasis on new synthesis and characterization methods. The journal is focused on the objects rather than on their applications. However, the research for new applications of original nano-structures & nano-objects in various fields such as nano-electronics, energy conversion, catalysis, drug delivery and nano-medicine is also welcome. The scope of Nano-Structures & Nano-Objects involves: -Metal and alloy nanoparticles with complex nanostructures such as shape control, core-shell and dumbells -Oxide nanoparticles and nanostructures, with complex oxide/metal, oxide/surface and oxide /organic interfaces -Inorganic semi-conducting nanoparticles (quantum dots) with an emphasis on new phases, structures, shapes and complexity -Nanostructures involving molecular inorganic species such as nanoparticles of coordination compounds, molecular magnets, spin transition nanoparticles etc. or organic nano-objects, in particular for molecular electronics -Nanostructured materials such as nano-MOFs and nano-zeolites -Hetero-junctions between molecules and nano-objects, between different nano-objects & nanostructures or between nano-objects & nanostructures and surfaces -Methods of characterization specific of the nano size or adapted for the nano size such as X-ray and neutron scattering, light scattering, NMR, Raman, Plasmonics, near field microscopies, various TEM and SEM techniques, magnetic studies, etc .