Influence of size and surface capping on photoluminescence and cytotoxicity of gold nanoparticles

Abstract

Hydrophilic and homogeneous sub-10 nm blue light-emitting gold nanoparticles (NPs) functionalized with different capping agents have been prepared by simple chemical routes. Structure, average, size, and surface characteristics of these NPs have been widely studied, and the stability of colloidal NP solutions at different pH values has been evaluated. Au NPs show blue PL emission, particularly in the GSH capped NPs, in which the thiol-metal core transference transitions considerably enhance the fluorescent emission. The influence of capping agent and NP size on cytotoxicity and on the fluorescent emission are analyzed and discussed in order to obtain Au NPs with suitable features for biomedical applications. Cytotoxicity of different types of gold NPs has been determined using NPs at high concentrations in both tumor cell lines and primary cells. All NPs used show high biocompatibility with low cytotoxicity even at high concentration, while Au-GSH NPs decrease viability and proliferation of both a tumor cell line and primary lymphocytes.Electronic supplementary materialThe online version of this article (10.1007/s11051-018-4406-0) contains supplementary material, which is available to authorized users.

Superficial Characteristics and Functionalization Effectiveness of Non-Toxic Glutathione-Capped Magnetic, Fluorescent, Metallic and Hybrid Nanoparticles for Biomedical Applications

“…The tripeptide glutathione (GSH) constitutes an interesting asset for functionalization, as it is a low-cost reagent that harnesses in its small frame three highly used moieties for bioconjugation, such as a thiol terminal group and also an amino and two carboxylic groups. In this sense, the present work follows previous ones, in which we presented the functionalization of different NPs with GSH [14,41,42]. In this work, we have utilized GSH to functionalize four types of NP: fluorescent CdTe QDs, iron oxide magnetic NPs, gold NPs and hybrid iron oxide magnetic-gold NPs, labeled in the text, as QD-GSH, Mag-GSH, Au-GSH and Au-Mag-GSH, respectively.…”

“…This ligand-metal charge transfer transition, produced due to the capping, can contribute to the relatively strong emission bands, in the blue range of the spectra, for the Au-GSH NPs, as shown in Figure 2d, where the PL emission spectra, recorded for the Au NPs colloidal solution (exciting at 317 nm), is shown. This emission could be an interesting feature for the use of this NPs for biomarker applications [42]. Figure 3a.…”

“…Based on our previous works, we have designed three rapid chemical routes to obtain small GSH-capped gold, magnetic iron oxide, and CdTe QDs [14,42]. In all these routes, we have promoted a reduction reaction, and we have used GSH to functionalize the NP surface.…”

Glutathione-magnetite nanoparticles: synthesis and physical characterization for application as MRI contrast agent

“…Even in the case of Quantum dots (QDs) with a potential toxic core, we concluded that there was no significative increase in cellular death when NP was present, due to the GSH entirely covers the surface of the NP. On the other hand, we have also reported the efficiency of GSH capping demonstrating that, after capping, the GSH molecule retains the capability of linking to biological species and also the ability for specifically links [35,36].…”

Role of gold nanoparticles in advanced biomedical applications

“…62 The properties of gold metal change signicantly as the size is reduced to the nano-scale (1-100 nm); this range results in much more than just a decorative metal piece. 20,63 In recent years, ne-scale GNPs have attracted tremendous interest from biomedical researchers owing to their useful and highly desirable physicochemical properties such as quantized charging and discharging, non-toxicity, high surface area to volume ratio, easy surface modication, photon induced heating, electromagnetic wave absorption and scattering, and optical and electronic properties. 22,25,53,64,65 In the modern era, GNPs have been widely used in biomedical elds.…”