Segmentability evaluation of back-scattered SEM images of multiphase materials.

Segmentation methods are very useful tools in the Electron Microscopy inspection of materials, enabling the extraction of quantitative results from microscopy images. Back-Scattered Electron (BSE) images carry information of the mean atomic number in the interaction volume and hence can be used to quantify the phase composition in multiphase materials. Since phase composition and proportion affects the material properties and hence its applications, the segmentation accuracy of such images rendered of critical importance for material science. In this work, the notion of segmentability for BSE images is proposed to define the ability of an image to be segmented accurately. This notion can be used to guide the image acquisition process so that segmentability is maximized and segmentation accuracy is ensured. An index is devised to quantify segmentability based on a combination of the modified Fisher Discrimination Ratio and of the second Minkowski functional capturing intensity and spatial aspects of BSE images respectively. The suggested Segmentability Index (SI) is validated in synthetic BSE images which are generated with a novel algorithm allowing the independent control of spatial distribution of phases and their grayscale intensity histograms. Additionally, SI is applied in real-synthetic BSE images, where the real greyscale distributions of Ordinary Portland Cement (OPC) clinker crystallographic phases are used, to demonstrate the ability of SI to indicate the optimum choice of critical image acquisition settings leading to the more accurate segmentation output.

VAR Fabric Modification: Inducing Antibacterial Properties, Altering Wettability/Water Repellence, and Understanding Reactivity at the Molecular Level.

The present work focuses on the surface coating of VAR technical fibers, consisting of 64% viscose (cellulose), 24% Kevlar, 10% other types of polyamides, and 2% antistatic polymers. Kevlar is an aramid material exhibiting excellent mechanical properties, while cellulose is a natural linear polymer composed of repeating ß-d-glucose units, having several applications in the materials industry. Herein, we synthesized novel, tailor-designed organic molecules possessing functional groups able to anchor on VAR fabrics and cellulose materials, thus altering their properties on demand. To this end, we utilized methyl-α-d-glucopyranose as a model compound, both to optimize the reaction conditions, before applying them to the material and to understand the chemical behavior of the material at the molecular level. The efficient coating of the VAR fabric with the tailor-made compounds was then implemented. Thorough characterization studies using Raman and IR spectroscopies as well as SEM imaging and thermogravimetric analysis were also carried out. The wettability and water repellency and antibacterial properties of the modified VAR fabrics were also investigated in detail. To the best of our knowledge, such an approach has not been previously explored, among other factors regarding the understanding of the anchoring mechanism at the molecular level. The proposed modification protocol holds the potential to improve the properties of various cellulose-based materials beyond VAR fabrics.

Non-graphitized carbon/Cu2O/Cu0 nanohybrids with improved stability and enhanced photocatalytic H2 production.

Cu2O is a highly potent photocatalyst, however photocorrosion stands as a key obstacle for its stability in photocatalytic technologies. Herein, we show that nanohybrids of Cu2O/Cu0 nanoparticles interfaced with non-graphitized carbon (nGC) constitute a novel synthesis route towards stable Cu-photocatalysts with minimized photocorrosion. Using a Flame Spray Pyrolysis (FSP) process that allows synthesis of anoxic-Cu phases, we have developed in one-step a library of Cu2O/Cu0 nanocatalysts interfaced with nGC, optimized for enhanced photocatalytic H2 production from H2O. Co-optimization of the nGC and the Cu2O/Cu0 ratio is shown to be a key strategy for high H2 production, > 4700 µmoles g-1 h-1 plus enhanced stability against photocorrosion, and onset potential of 0.234 V vs. RHE. After 4 repetitive reuses the catalyst is shown to lose less than 5% of its photocatalytic efficiency, while photocorrosion was < 6%. In contrast, interfacing of Cu2O/Cu0 with graphitized-C is not as efficient. Raman, FT-IR and TGA data are analyzed to explain the undelaying structural functional mechanisms where the tight interfacing of nGC with the Cu2O/Cu0 nanophases is the preferred configuration. The present findings can be useful for wider technological goals that demand low-cost engineering, high stability Cu-nanodevices, prepared with industrially scalable process.

Kevlar®, Nomex®, and VAR Modification by Small Organic Molecules Anchoring: Transfusing Antibacterial Properties and Improving Water Repellency.

The surface modification of fabrics composed of Kevlar®, Nomex®, or VAR was extensively investigated. Kevlar® and Nomex® are widely-utilized aramid materials, whereas VAR is a technical fabric comprising 64% viscose, 24% para-aramid (Kevlar®), 10% polyamide, and 2% antistatic fibers. Both aramid materials and cellulose/viscose exhibit exceptional mechanical properties that render them valuable in a wide range of applications. For the herein studied modification of Kevlar®, Nomex®, and VAR, we used small organic molecules 3-allyl-5,5-dimethylhydantoin (ADMH) and 3-(acrylamidopropyl)trimethylammonium chloride (APTAC), which were anchored onto the materials under study via graft polymerization. By doing so, excellent antibacterial properties were induced in the three studied fabrics. Their water repellency was improved in most cases as well. Extensive characterization studies were conducted to probe the properties of the modified materials, employing Raman and FTIR spectroscopies, Scanning Electron Microscopy (SEM), and thermogravimetric analysis (TGA).

Covalently Modified Kevlar Fabric Incorporating Graphene Oxide with Enhanced Antibacterial Properties and Preserved Strength.

This work describes a multi-step modification process for the covalent transformation of Kevlar fabric en route to the incorporation of graphene oxide (GO) nanosheets. Spectroscopic, thermal and microscopy imaging techniques have been employed to follow step-by-step the modification of Kevlar and the formation of the corresponding Kevlar-GO hybrid fabric. The level of Kevlar's functionalization can be controlled with the nitration time, the first reaction in the multi-sequence organic transformations, for obtaining the hybrid fabric with a content of GO up to 30 %. Most importantly, the covalent post-modification of Kevlar does not occur in the expense of the other excellent mechanical properties of the fabric. Under optimal conditions, the Kevlar-GO hybrid fabric shows a 20 % enhancement of the ultimate strength. Notably, when the Kevlar-GO hybrid fabric was exposed to cyanobacterial Synechococcus the bacteria growth was fully inhibited. Overall, the covalently modified fabric demonstrated significant antibacterial behavior, excellent strength and stability under common processes. Due to its simplicity, the methodology presented in this work not only promises to result in a standard procedure to functionalize the mer units of Kevlar with a variety of chemicals and nanomaterials but it can be also extended for the modification and hybridization of other fabrics.

In Tandem Control of La-Doping and CuO-Heterojunction on SrTiO3 Perovskite by Double-Nozzle Flame Spray Pyrolysis: Selective H2 vs. CH4 Photocatalytic Production from H2O/CH3OH.

ABO3 perovskites offer versatile photoactive nano-templates that can be optimized towards specific technologies, either by means of doping or via heterojunction engineering. SrTiO3 is a well-studied perovskite photocatalyst, with a highly reducing conduction-band edge. Herein we present a Double-Nozzle Flame Spray Pyrolysis (DN-FSP) technology for the synthesis of high crystallinity SrTiO3 nanoparticles with controlled La-doping in tandem with SrTiO3/CuO-heterojunction formation. So-produced La:SrTiO3/CuO nanocatalysts were optimized for photocatalysis of H2O/CH3OH mixtures by varying the La-doping level in the range from 0.25 to 0.9%. We find that, in absence of CuO, the 0.9La:SrTiO3 material achieved maximal efficient photocatalytic H2 production, i.e., 12 mmol g-1 h-1. Introduction of CuO on La:SrTiO3 enhanced selective production of methane CH4. The optimized 0.25La:SrTiO3/0.5%CuO catalyst achieved photocatalytic CH4 production of 1.5 mmol g-1 h-1. Based on XRD, XRF, XPS, BET, and UV-Vis/DRS data, we discuss the photophysical basis of these trends and attribute them to the effect of La atoms in the SrTiO3 lattice regarding the H2-production, plus the effect of interfacial CuO on the promotion of CH4 production. Technology-wise this work is among the first to exemplify the potential of DN-FSP for scalable production of complex nanomaterials such as La:SrTiO3/CuO with a diligent control of doping and heterojunction in a single-step synthesis.

Small anticancer drug release by light: Photochemical internalization of porphyrin-ß-cyclodextrin nanoparticles.

Aiming to engineer simple, neutral, strongly amphiphilic photoactive nanoparticles (NPs) to specifically target cancer cell lysosomes for drug transport and light-controlled release, new conjugates of ß-cyclodextrin with highly hydrophobic triphenylporphyrin bearing different alkyl chains, were synthesized. Although differently sized, all conjugates self-assemble into ~60 nm NPs in water and display similar photoactivity. The NPs target selectively the lysosomes of breast adenocarcinoma MCF-7 cells, embedding in vesicular membranes, as experiments with model liposomes indicate. Either empty or drug-loaded, the NPs lack dark toxicity for 48 h. They bind with differently structured anticancer drugs tamoxifen and gemcitabine as its N-adamantyl derivative. Red light irradiation of cells incubated with drug-loaded NPs results in major reduction of viability (>85 %) for 48 h displaying significant synergy of photo-chemotoxicity, as opposed to empty NPs, and to loaded non-irradiated NPs, in manifestation of photochemical internalization (PCI). Our approach expands the field of PCI into different small molecule chemotherapeutics.

Segmentation of SEM images of multiphase materials: When Gaussian mixture models are accurate?

Scanning electron microscopy has been a powerful technique to investigate the structural and chemical properties of multiphase materials on micro and nanoscale due to its high-resolution capabilities. One of the main outcomes of the SEM-based analysis is the calculation of the fractions of material components constituting the multiphase material by means of the segmentation of their back scattered electron SEM images. In order to segment multiphase images, Gaussian mixture models (GMMs) are commonly used based on the deconvolution of the image pixel histogram. Despite its extensive use, the accuracy of GMM predictions has not been validated yet. In this paper, we proceed to a systematic study of the evaluation of the accuracy and the limitations of the GMM method when applied to the segmentation of a four-phase material. To this end, first, we build a modelling framework and propose an index to quantify the accuracy of GMM predictions for all phases. Then we apply this framework to calculate the impact of collective parameters of image histogram on the accuracy of GMM predictions. Finally, some rules of thumb are concluded to guide SEM users about the suitability of using GMM for the segmentation of their SEM images based only on the inspection of the image histogram. A suitable histogram for GMM is a histogram with number of peaks equal to the number of Gaussian components, and if that is not the case, kurtosis and skewness should be smaller than 2.35 and 0.1, respectively.

Iron oxide nanoflowers encapsulated in thermosensitive fluorescent liposomes for hyperthermia treatment of lung adenocarcinoma.

Magnetic hyperthermia (MHT) is in the spotlight of nanomedical research for the treatment of cancer employing magnetic iron oxide nanoparticles and their intrinsic capability for heat dissipation under an alternating magnetic field (AMF). Herein we focus on the synthesis of iron oxide nanoflowers (Nfs) of different sizes (15 and 35 nm) and coatings (bare, citrate, and Rhodamine B) while comparing their physicochemical and magnetothermal properties. We encapsulated colloidally stable citrate coated Nfs, of both sizes, in thermosensitive liposomes via extrusion, and RhB was loaded in the lipid bilayer. All formulations proved hemocompatible and cytocompatible. We found that 35 nm Nfs, at lower concentrations than 15 nm Nfs, served better as nanoheaters for magnetic hyperthermia applications. In vitro, magnetic hyperthermia results showed promising therapeutic and imaging potential for RhB loaded magnetoliposomes containing 35 nm Nfs against LLC and CULA cell lines of lung adenocarcinoma.

Bimetallic gold-platinum nanoparticles as a drug delivery system coated with a new drug to target glioblastoma.

A drug delivery nanosystem of noble bimetallic nanoparticles (NPs) which consists of Au NPs capped with Pt NPs (Au@Pt NPs) is constructed and functionalised with a quinazoline based small molecule (Au@Pt@Q NPs), acting as a theranostic agent against glioblastoma. Two different hydrothermal synthetic procedures for bimetallic Au@Pt NPs are presented and the resulting nanostructures are fully characterised by means of spectroscopic and microscopic methods. The imaging and targeting capacity of the new drug delivery system is assessed through fluorescent optical microscopy and cytotoxicity evaluations. The constructed Au@Pt NPs consist a monodispersed colloidal solution of 25 nm with photoluminescent, fluorescent and X-Ray absorption properties that confirm their diagnostic potential. Haemolysis testing demonstrated that Au@Pt NPs are biocompatible and fluorescent microscopy confirmed their entering the cells. Cytological evaluation of the NPs through MTT assay showed that they do not inhibit the proliferation of control cell line HEK293, whereas they are toxic in U87MG, U251 and D54 glioblastoma cell lines; rendering them selective targeting agents for treating glioblastoma.

Composite Nanoarchitectonics of Photoactivated Titania-Based Materials with Anticancer Properties.

The synthesis of titania-based composite materials with anticancer potential under visible-light irradiation is the aim of this study. In specific, titanium dioxide (TiO2) nanoparticles (NPs) chemically modified with silver were embedded in a stimuli-responsive microgel (a crosslinked interpenetrating network (IP) network that was synthesized by poly (N-Isopropylacrylamide) and linear chains of polyacrylic acid sodium salt, forming composite particles. The ultimate goal of this research, and for our future plans, is to develop a drug-delivery system that uses optical fibers that could efficiently photoactivate NPs, targeting cancer cells. The produced Ag-TiO2 NPs, the microgel and the composite materials were characterized through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), micro-Raman spectroscopy, ultraviolet-visible spectroscopy (UV-Vis), dynamic light scattering (DLS) and transmission electron microscopy (TEM). Our results indicated that Ag-TiO2 NPs were successfully embedded within the thermoresponsive microgel. Either Ag-TiO2 NPs or the composite materials exhibited high photocatalytic degradation efficiency on the pollutant rhodamine B and significant anticancer potential under visible-light irradiation.

Visible Light Trapping against Charge Recombination in FeOx-TiO2 Photonic Crystal Photocatalysts.

Tailoring metal oxide photocatalysts in the form of heterostructured photonic crystals has spurred particular interest as an advanced route to simultaneously improve harnessing of solar light and charge separation relying on the combined effect of light trapping by macroporous periodic structures and compositional materials' modifications. In this work, surface deposition of FeOx nanoclusters on TiO2 photonic crystals is investigated to explore the interplay of slow-photon amplification, visible light absorption, and charge separation in FeOx-TiO2 photocatalytic films. Photonic bandgap engineered TiO2 inverse opals deposited by the convective evaporation-induced co-assembly method were surface modified by successive chemisorption-calcination cycles using Fe(III) acetylacetonate, which allowed the controlled variation of FeOx loading on the photonic films. Low amounts of FeOx nanoclusters on the TiO2 inverse opals resulted in diameter-selective improvements of photocatalytic performance on salicylic acid degradation and photocurrent density under visible light, surpassing similarly modified P25 films. The observed enhancement was related to the combination of optimal light trapping and charge separation induced by the FeOx-TiO2 interfacial coupling. However, an increase of the FeOx loading resulted in severe performance deterioration, particularly prominent under UV-Vis light, attributed to persistent surface recombination via diverse defect d-states.

Graphene Quantum Dot-TiO2 Photonic Crystal Films for Photocatalytic Applications.

Photonic crystal structuring has emerged as an advanced method to enhance solar light harvesting by metal oxide photocatalysts along with rational compositional modifications of the materials' properties. In this work, surface functionalization of TiO2 photonic crystals by blue luminescent graphene quantum dots (GQDs), n-π* band at ca. 350 nm, is demonstrated as a facile, environmental benign method to promote photocatalytic activity by the combination of slow photon-assisted light trapping with GQD-TiO2 interfacial electron transfer. TiO2 inverse opal films fabricated by the co-assembly of polymer colloidal spheres with a hydrolyzed titania precursor were post-modified by impregnation in aqueous GQDs suspension without any structural distortion. Photonic band gap engineering by varying the inverse opal macropore size resulted in selective performance enhancement for both salicylic acid photocatalytic degradation and photocurrent generation under UV-VIS and visible light, when red-edge slow photons overlapped with the composite's absorption edge, whereas stop band reflection was attenuated by the strong UVA absorbance of the GQD-TiO2 photonic films. Photoelectrochemical and photoluminescence measurements indicated that the observed improvement, which surpassed similarly modified benchmark mesoporous P25 TiO2 films, was further assisted by GQDs electron acceptor action and visible light activation to a lesser extent, leading to highly efficient photocatalytic films.

Modified magnetic core-shell mesoporous silica nano-formulations with encapsulated quercetin exhibit anti-amyloid and antioxidant activity.

Targeted tissue drug delivery is a challenge in contemporary nanotechnologically driven therapeutic approaches, with the interplay interactions between nanohost and encapsulated drug shaping the ultimate properties of transport, release and efficacy of the drug at its destination. Prompted by the need to pursue the synthesis of such hybrid systems, a family of modified magnetic core-shell mesoporous silica nano-formulations was synthesized with encapsulated quercetin, a natural flavonoid with proven bioactivity. The new nanocarriers were produced via the sol-gel process, using tetraethoxysilane as a precursor and bearing a magnetic core of surface-modified monodispersed magnetite colloidal superparamagnetic nanoparticles, subsequently surface-modified with polyethylene glycol 3000 (PEG3k). The arising nano-formulations were evaluated for their textural and structural properties, exhibiting enhanced solubility and stability in physiological media, as evidenced by the loading capacity, entrapment efficiency results and in vitro release studies of their load. Guided by the increased bioavailability of quercetin in its encapsulated form, further evaluation of the biological activity of the magnetic as well as non-magnetic core-shell nanoparticles, pertaining to their anti-amyloid and antioxidant potential, revealed interference with the aggregation of ß-amyloid peptide (Aß) in Alzheimer's disease, reduction of Aß cellular toxicity and minimization of Aß-induced Reactive Oxygen Species (ROS) generation. The data indicate that the biological properties of released quercetin are maintained in the presence of the host nanocarriers. Collectively, the findings suggest that the emerging hybrid nano-formulations can function as efficient nanocarriers of hydrophobic natural flavonoids in the development of multifunctional nanomaterials toward therapeutic applications.

Heterostructured CoOx-TiO2 Mesoporous/Photonic Crystal Bilayer Films for Enhanced Visible-Light Harvesting and Photocatalysis.

Heterostructured bilayer films, consisting of co-assembled TiO2 photonic crystals as the bottom layer and a highly performing mesoporous P25 titania as the top layer decorated with CoOx nanoclusters, are demonstrated as highly efficient visible-light photocatalysts. Broadband visible-light activation of the bilayer films was implemented by the surface modification of both titania layers with nanoscale clusters of Co oxides relying on the chemisorption of Co acetylacetonate complexes on TiO2, followed by post-calcination. Tuning the slow photon regions of the inverse opal supporting layer to the visible-light absorption of surface CoOx oxides resulted in significant amplification of salicylic-acid photodegradation under visible and ultraviolet (UV)-visible light (Vis), outperforming benchmark P25 films of higher titania loading. This enhancement was related to the spatially separated contributions of slow photon propagation in the inverse opal support layer assisted by Bragg reflection toward the CoOx-modified mesoporous P25 top layer. This effect indicates that photonic crystals may be highly effective as both photocatalytically active and backscattering layers in multilayer photocatalytic films.

Synthesis of biocompatible silver nanoparticles by a modified polyol method for theranostic applications: Studies on red blood cells, internalization ability and antibacterial activity.

Recently, there has been ongoing research in the field of nanotechnology and nanomedicine aiming at developing multifunctional biomaterials using noble metals. The unique properties of silver (Ag) are known from ancient times and thus are being explored for their behavior on the nano scale. Silver shows high antimicrobial activity against different microorganisms, while modification of the surface of its nanostructures can be useful in active targeting regarding cancer treatment. During the synthetic procedure, in order to obtain a more uniform sample of silver nanoparticles (Ag NPs) with spherical morphology, a stabilizer is essential. The stabilizers used not only control the progression of the reaction, but also increases the biocompatibility of the NPs. Thus, we managed to synthesize spherical and rod-like Ag NPs via a polyol method and stabilize them with polyvinylpyrrolidone (PVP). The resulted Ag NPs were characterized morphologically with Transmission Electron Microscopy (TEM) and further confirmed by their structural characterization (FT-IR, UV-Vis, Dynamic Light Scattering (DLS) and Zeta Potential). For their biocompatibility profile, we studied their interaction with red blood cells (RBCs) through hemolysis assay and we monitored their structural alterations through SEM. The antimicrobial activity was tested with the agar diffusion disc assay for Gram negative and Gram positive microorganisms E. coli and S. aureus respectively. Nanoparticles' (NPs) internalization and localization studies in cancer cells were monitored with fluorescence microscopy in MCF-7 and U87-MG. According to our results it is worth it to investigate the potential of these nanomaterials since they can have a significant role in applications of theranostics in nanomedicine.

Novel Isatin Thiosemicarbazone Derivatives as Potent Inhibitors of ß-Amyloid Peptide Aggregation and Toxicity.

Inhibition of ß-amyloid peptide (Αß) aggregation in Alzheimer's disease (AD) is among the therapeutic approaches against AD which still attracts scientific research interest. In the search for compounds that interact with Aß and disrupt its typical aggregation course toward oligomeric or polymeric toxic assemblies, small organic molecules of natural origin, combining low molecular weight (necessary blood-brain barrier penetration) and low toxicity (necessary for pharmacological application), are greatly sought after. Isatin (1H-indoline-2,3-dione), a natural endogenous indole, and many of its derivatives exhibit a wide spectrum of neuropharmacological and chemotherapeutic properties. The synthesis and biological evaluation of four new isatins as inhibitors of Aß aggregation is presented herein. In these derivatives, the N-phenyl thiosemicarbazide moiety is joined at the 3-oxo position of isatin through Schiff base formation, and substitutions are present at the indole nitrogen and position 5 of the isatin core. Biophysical studies employing circular dichroism, thioflavin T fluorescence assay, and transmission electron microscopy reveal the potential of the isatin thiosemicarbazones (ITSCs) to alter the course of Αß aggregation, with two of the derivatives exhibiting outstanding inhibition of the aggregation process, preventing completely the formation of amyloid fibrils. Furthermore, in in vitro studies in primary neuronal cell cultures, the ITSCs were found to inhibit the Aß-induced neurotoxicity and reactive oxygen species production at concentrations as low as 1 µM. Taken all together, the novel ITSCs can be considered as privileged structures for further development as potential AD therapeutics.

Nanographene oxide-TiO2 photonic films as plasmon-free substrates for surface-enhanced Raman scattering.

The development of nanostructured semiconductors with tailored morphology and electronic properties for surface-enhanced Raman scattering (SERS) has been attracting significant attention as a promising alternative to conventional coinage metal SERS substrates. In this work, functionalized TiO2 photonic crystals by graphene oxide nanocolloids (nanoGO) are demonstrated as highly sensitive, recyclable, plasmon-free SERS substrates that combine slow-photon amplification effects with the high adsorption capacity and surface reactivity of GO nanosheets. Comparative evaluation of photonic band gap engineered nanoGO-TiO2 inverse opal films was performed on methylene blue SERS detection under different laser excitations in combination with rigorous theoretical simulations of the photonic band structure. A very low detection limit of 6 × 10-7 M and an enhancement factor of 5 × 104 along with excellent self-cleaning performance and reusability could be achieved by the interplay of slow-photon effects assisted by interfacial charge transfer between the analyte and the nanoGO-TiO2 semiconducting substrate. Slow-photon management in combination with judicious engineering of chemical enhancement in photonic nanostructures is accordingly proposed as an advanced approach for the design of efficient dielectric SERS substrates.

Spin-Crossover Phenomenon in Microcrystals and Nanoparticles of a [Fe(2-mpz)2Ni(CN)4] Two-Dimensional Hofmann-Type Polymer: A Detailed Nano-Topographic Study.

The diamagnetic two-dimensional Hofmann-type metal-organic framework [ZnII(2-mpz)2Ni(CN)4] has been successfully synthesized along with its isostructural hysteretic spin-crossover FeII analogue in the form of both bulk microcrystalline powder and nanoparticles. Detailed atomic force microscopy topographic study revealed a nanogrowth relationship between the height and length of the nanoparticle.

Gold nanoparticle decorated pH-sensitive polymeric nanocontainers as a potential theranostic agent.

A pH-sensitive system of hollow P(MAA-co-MBA-co-AA) nanocontainers (NCs) modified with gold nanoparticles (GNCs) has been developed for theranostic applications, drug delivery and real time monitoring through imaging. The GNCs were synthesised by the distillation precipitation copolymerization procedure followed by in situ synthesis and embodiment of gold nanoparticles on the polymeric matrix (CSNs). Separately, citrate capped gold nanoparticles (GNPs) were also synthesized and compared with the GNCs for their fluorescence and cellular localization ability. The GNCs were tested for their drug loading and release behavior in response to the anticancer drug doxorubicin (DOX) at different pH values. Sustained drug release was observed at acidic pH. The viability of MCF-7 breast cancer cells and HEK-293 human embryonic kidney cells in relation to the GNCs, GNPs, GNC@DOX and DOX was also evaluated. GNCs and GNPs at the tested concentrations did not inhibit proliferation at either cell lines, whereas the GNCs@DOX presented comparable results. Cellular migration of MCF-7 cells treated with GNCs or GNPs was evaluated through the scratch-wound healing assay but no significant inhibition was detected. GNCs' and GNPs' fluorescence ability was exploited for assessing cellular localization through confocal laser scanning microscopy. GNCs after only 1 h of treatment were found in the cytoplasm of MCF7 cells, whereas GNCs@DOX were localized in the nucleus; the desirable site of action of DOX.