Synthesis of Ultrastable Copper Sulfide Nanoclusters via Trapping the Reaction Intermediate: Potential Anticancer and Antibacterial Applications

Abstract

Copper-based nanomaterials have broad applications in electronics, catalysts, solar energy conversion, antibiotics, tissue imaging, and photothermal cancer therapy. However, it is challenging to prepare ultrasmall and ultrastable CuS nanoclusters (NCs) at room temperature. In this article, a simple method to synthesize water-soluble, monodispersed CuS NCs is reported based on the strategy of trapping the reaction intermediate using thiol-terminated, alkyl-containing short-chain poly(ethylene glycol)s (HS-(CH2)11-(OCH2CH2)6-OH, abbreviated as MUH). The MUH-coated CuS NCs have superior stability in solutions with varied pH values and are stable in pure water for at least 10 months. The as-prepared CuS NCs were highly toxic to A549 cancer cells at a concentration of higher than 100 μM (9.6 μg/mL), making them be potentially applicable as anticancer drugs via intravenous administration by liposomal encapsulation or by direct intratumoral injection. Besides, for the first time, CuS NCs were used for antibacterial application, and 800 μM (76.8 μg/mL) CuS NCs could completely kill the E. coli cells through damaging the cell walls. Moreover, the NCs synthesized here have strong near-infrared (NIR) absorption and can be used as a candidate reagent for photothermal therapy and photoacoustic imaging. The method of trapping the reaction intermediate for simple and controlled synthesis of nanoclusters is generally applicable and can be widely used to synthesize many metal-based (such as Pt, Pd, Au, and Ag) nanoclusters and nanocrystals.

Development of Copper Nanoclusters for In Vitro and In Vivo Theranostic Applications

“…At the cellular level, the efficiency of cellular uptake of the NCs is linked with the cluster size, too. This has been suggested by an earlier study, which observed no cytotoxicity in A549 cells after 24 h exposure of the cells to 30 nm diameter CuS clusters at a concentration of 800 × 10 −6 m . Upon a reduction in the size of the clusters to around 5 nm, exposure of the cells to a concentration of 50 × 10 −6 m was found to cause the cell viability to drop to 15% .…”

Application of CuS-functionalized ZnO nanoflakes for a paper-based photoelectrochemical immunoassay using an in situ electron donor producing strategy

“…[26][27][28][29] CuS is a potential material for visible light photocatalysis without the use of any toxic elements due to its narrow bad gap. [26][27][28][29] CuS is a potential material for visible light photocatalysis without the use of any toxic elements due to its narrow bad gap.…”

Polyethyleneimine-capped silver nanoclusters for microRNA oligonucleotide delivery and bacterial inhibition

“…23 Briefly, log-phase bacteria incubated with 14.25 µg/mL of PEI and PEI-AgNCs for 48 hours were collected by centrifugation at 5,000 rpm for 5 minutes and fixed with 2.5% glutaraldehyde overnight at 4°C. After washing with PBS three times, the bacterial cells were dehydrated through a sequential treatment of 30%, 50%, 70%, 80%, 90%, 95%, and 100% ethanol for 15 minutes and imaged using an SEM (ULTRA Plus; Carl Zeiss AG).…”