Stable Colloidal Dispersions Research Articles

Stable colloidal dispersions of fullerene C60, curcumin and C60-curcumin in water as potential antioxidants

Despite many advantages, the practical application of fullerene C60 and curcumin (CUR) has been limited by their hydrophobic nature, deficient solubility in aqueous media and, therefore, poor bioavailability. In this study, aqueous nanoformulations containing C60 and CUR in the absence and presence of three solubility enhancers, β-cyclodextrin (CD), Tween 80 (T80) and polyvinylpyrrolidone (PVP), were prepared and subjected to the antioxidant activity assessment. The content of C60 and CUR, stability, size and morphology of nanoparticles were determined using UV–vis, DLS and SEM techniques. Contrary to better solubility of pure C60 than the corresponding C60-CUR system, the solubilization of CUR in hybrid suspensions was improved compared to corresponding pure CUR suspensions, with the exception of the C60-CUR-PVP formulation. The DLS results revealed nearly monodisperse nature of CUR-T80 nanoformulation, while other ones ranged from widely dispersed to polydispersed. Depending on the type of solubilizer, similarity was observed in the particle size distributions of T80- and PVP-coated nanoformulations as well as water and CD nanoformulations. The presence of T80 differently and significantly reduces the particle size in all three nanoformulations, while PVP slightly reduces CUR-based nanoparticles but increases the size of C60 nanoparticles. Zeta potential values, ranging from − 9 mV to − 34 mV, show variation in the starting stability of nanoparticles, from unstable or relatively stable three PVP formulations and C60-T80 to highly stable CUR-T80 and C60-water. Compared to water nanoformulations as a control, SEM images of dispersant-coated nanoparticles lost the visible morphology of active components, showing variation in their morphology depending on the type of dispersant and active component used. Nanoformulations containing CUR in PVP and T80 expressed a very good antioxidant potential in DPPH radical scavenging assay, much stronger than ascorbic acid. At the same time, a moderate to high antioxidant activity in β-carotene bleaching assay was reached in PVP and T80 nanoformulations containing C60, CUR, and their noncovalent hybrid, as well. Our studies have shown that T80 and PVP colloidal systems containing C60-CUR hybrid, but also their individual components, can be used as stable antioxidant nanoformulations with potential application in the field of food and pharmacology.

Structural Design of Multidentate Copolymers as Compact Quantum Dot Coatings for Live-Cell Single-Particle Imaging.

Quantum dots (QDs) are a class of semiconductor nanocrystal used broadly as fluorescent emitters for analytical studies in the life sciences. These nanomaterials are particularly valuable for single-particle imaging and tracking applications in cells and tissues. An ongoing technological goal is to reduce the hydrodynamic size of QDs to enhance access to sterically hindered biological targets. Multidentate polymer coatings are a focus of these efforts and have resulted in compact and stable QDs with hydrodynamic diameters near 10 nm. New developments are needed to reach smaller sizes to further enhance transport through pores in cells and tissues. Here, we describe how structural characteristics of linear multidentate copolymers determine hydrodynamic size, colloidal stability, and biomolecular interactions of coated QDs. We tune copolymer composition, degree of polymerization, and hydrophilic group length, and coat polymers on CdSe and (core)shell (HgCdSe)CdZnS QDs. We find that a broad range of polymer structures and compositions yield stable colloidal dispersions; however, hydrodynamic size minimization and nonspecific binding resistance can only be simultaneously achieved within a narrow range of properties, requiring short polymers, balanced compositions, and small nanocrystals. In quantitative single-molecule imaging assays in synapses of live neurons, size reduction progressively increases labeling specificity of neurotransmitter receptors. Our findings provide a design roadmap to next-generation QDs with sizes approaching fluorescent protein labels that are the standard of many live-cell biomolecular studies.

Charged Colloids at the Metal–Electrolyte Interface

We discuss the peculiarities of the structure of the interface between a metal and a stable colloidal dispersion of charged nanoparticles in an electrolyte. It is demonstrated that a quasi-2D ionic structure of elevated density arises in its vicinity due to the effect of electrostatic image forces. The stabilized colloidal particles, being electroneutral and spatially distributed objects in the bulk of the electrolyte and approaching the interface, are attracted to it. In their turn, the counterions forming their coat partially retract into the 2D-layer, which results in an acquisition by the colloidal particle of the effective charge eZ*≫e and which, together with its mirror image, creates the electric dipole. The formed dipoles, possessing the moments directed perpendicularly to the interface, form the gas with repulsion between particles. The intensity of this repulsion, evidently, depends on the value of the effective charge eZ* acquired by the nanoparticle having lost a number of counterions. It can be related to the value of the excess osmotic pressure Posm measured in the experiment. On the other hand, this effective charge can be connected by means of the simple geometric consideration with the structural charge eZ of the nanoparticle core being in the bulk of the electrolyte.

Fast Scalable Synthetic Methodology to Prepare Nanoflower‐Shaped Bi/BiOClxBr1−x Heterojunction for Efficient Immobilized Photocatalytic Reactors under Visible Light Irradiation (Adv. Sustainable Syst. 4/2022)

Water Treatment Advanced hybrid heterojunctions are promising materials for the photodegradation of pollutants from wastewater. In article number 2100267, Maha Al-Qunaibit, Tawfik A. Saleh and co-workers successfully prepare highly stable colloidal dispersions of Bi/BiOClxBr1−x heterojunctions with an exposed (001) facet. The Bi/BiOCl0.8Br0.2 film with 3D flower-like morphology demonstrates the highest photocatalytic degradation rate of rhodamine RhB aqueous solution under visible solar light.

Preparation of redispersed WO3 nanoparticles in N-methyl-2-pyrrolidone by ethylene glycol as a dispersing agent

In this experimental work, a procedure was introduced to redisperse WO3 nanoparticles in NMP. The primary nanoparticles were non-dispersible in NMP and the method includes dissolving the nanoparticles into an appropriate solution and adding ethylene glycol as dispersing agent. The optimum temperature and drying time to obtain a transparent and high stable colloidal dispersion were achieved. The final product powder redispersed in NMP and spin-coated on glass substrates. The surface of the layers was analyzed by scanning electron microscopy and ultraviolet–visible spectroscopy. The dynamic light scattering (DLS) technique was used to study the distribution, charge and zeta potential of the nanoparticles in the NMP matrix. Also, Energy-dispersive X-ray analysis (EDX) of the sample after dispersing and X-ray diffraction analysis (XRD) were taken. The results show a high stability of the final WO3 nanoparticles in NMP solution.

Bulk-like emission in the visible spectrum of colloidal LiYF4:Pr nanocrystals downsized to 10 nm.

Though Pr3+ doped LiYF4 (LiYF4:Pr3+) bulk crystals are a well-known laser gain material with several radiative transitions, their nanocrystal counterparts have not been investigated with regards to these. Through downsizing to the nanoscale, novel applications are expected, especially in composite photonic devices. For example, nanocrystals in stable colloidal form with narrow size distribution are highly desirable to reduce scattering in such composites. Herein, we synthesized monodispersed LiYF4:Pr3+ nanocrystals having a size of 10 nm resulting in colorless clear stable colloidal dispersions and conducted an extensive optical characterization for the first time. We observed unexpected yet intense emission with excited state lifetimes comparable to bulk crystals in the visible spectrum through excitation at 444 nm and 479 nm. In macroscopic bulk crystals, this emission is only exploitable through excitation of a different, subjacent energy level. A comprehensive comparison to the bulk crystals provides deeper insight into the excitation mechanism and performance of these nanocrystals. The presented results pave the way for developing application-oriented LiYF4:Pr3+ nanocrystals as emitters with tailored properties for quantum optics or biomedical applications.

Polymer Micro and Nanoparticles Containing B(III) Compounds as Emissive Soft Materials for Cargo Encapsulation and Temperature-Dependent Applications.

Polymer nanoparticles doped with fluorescent molecules are widely applied for biological assays, local temperature measurements, and other bioimaging applications, overcoming several critical drawbacks, such as dye toxicity, increased water solubility, and allowing imaging of dyes/drug delivery in water. In this work, some polymethylmethacrylate (PMMA), polyvinylpyrrolidone (PVP) and poly(styrene-butadiene-styrene) (SBS) based micro and nanoparticles with an average size of about 200 nm and encapsulating B(III) compounds have been prepared via the reprecipitation method by using tetrahydrofuran as the oil phase and water. The compounds are highly hydrophobic, but their encapsulation into a polymer matrix allows obtaining stable colloidal dispersions in water (3.39 µM) that maintain the photophysical behavior of these dyes. Although thermally activated non-radiative processes occur by increasing temperature from 25 to 80 °C, the colloidal suspension of the B(III) particles continues to emit greenish light (λ = 509 nm) at high temperatures. When samples are cooling back to room temperature, the emission is restored, being reversible. A probe of concept drug delivery study was conducted using coumarin 6 as a prototype of a hydrophobic drug.

Water-Soluble Luminescent Silicon Nanocrystals by Plasma-Induced Acrylic Acid Grafting and PEGylation.

Luminescent silicon nanocrystals are promising nanomaterials for biomedical applications due to their unique optical properties and biocompatibility. Here, we demonstrate a two-step surface modification approach coupling gas-phase and liquid-phase methods to synthesize PEGylated acrylic acid grafted silicon nanocrystals with near-infrared emission in water and biological media. First, acrylic acid grafted silicon nanocrystals are synthesized by an all-gas-phase approach on a millisecond time scale, omitting high temperature and postpurification processes. Subsequently, room-temperature PEGylation is carried out with these acrylic acid grafted silicon nanocrystals, yielding stable colloidal dispersions in both water and high ionic strength Tyrode's buffer with 20-30 nm hydrodynamic diameters. The PEGylated silicon nanocrystals exhibit photoluminescence in the 650-900 nm near-IR window with quantum yields of ∼30% and ∼13% in deionized water and Tyrode's buffer, respectively, after a 7-day oxidation in water. The surface-functionalized Si NCs exhibit relatively small toxicity to MDA-MB-231 cells at concentrations relevant to bioimaging applications.

Fast Scalable Synthetic Methodology to Prepare Nanoflower‐Shaped Bi/BiOClxBr1−x Heterojunction for Efficient Immobilized Photocatalytic Reactors under Visible Light Irradiation

AbstractThe metal/photocatalyst heterojunction has demonstrated an excellent capability for pollutant degradation under visible light irradiation. In this study, for the first time, highly stable colloidal dispersions of Bi/BiOClxBr1−x heterojunction with an exposed (001) facet are successfully prepared from inorganic simple salts using low‐frequency ultrasound irradiation (LFUI) at ambient conditions without further post‐treatment. The colloidal dispersion series of Bi/BiOClxBr1−x heterojunction (x = 0, 0.2, 0.5, 0.8 and 1) is simply obtained by adding stoichiometric aqueous solutions of NaCl and NaBr, into an acidic aqueous solution of Bi(NO)3.5H2O in a typical ultrasonication bath at room temperature within ≈5 min. Bi/BiOClxBr1−x heterojunction films are also fabricated using a simple drop‐casting technique and tested as immobilized photocatalytic reactors. Compared to its counterparts, the Bi/BiOCl0.8Br0.2 film possesses a 3D flower‐like morphology with a highly exposed (001) facet showing the highest electron‐hole generation and separation efficiencies. In addition, the Bi/BiOCl0.8Br0.2 film demonstrates the highest photocatalytic degradation rate of the rhodamine RhB aqueous solutions (≈5 ppm), achieving ≈99% in 60 min under the visible light component of the solar spectrum. This study demonstrates the potential of LFUI as a rapid scalable synthetic strategy for cost‐effective and energy‐efficient practical production of highly active immobilized photocatalytic reactors.

Microplasma Band Structure Engineering in Graphene Quantum Dots for Sensitive and Wide-Range pH Sensing.

pH sensing using active nanomaterials is promising in many fields ranging from chemical reactions to biochemistry, biomedicine, and environmental safety especially in the nanoscale. However, it is still challenging to achieve nanotechnology-enhanced rapid, sensitive, and quantitative pH detection with stable, biocompatible, and cost-effective materials. Here, we report a rational design of nitrogen-doped graphene quantum dot (NGQD)-based pH sensors by boosting the NGQD pH sensing properties via microplasma-enabled band-structure engineering. Effectively and economically, the emission-tunable NGQDs can be synthesized from earth-abundant chitosan biomass precursor by controlling the microplasma chemistry under ambient conditions. Advanced spectroscopy measurements and density functional theory (DFT) calculations reveal that functionality-tuned NGQDs with enriched -OH functional groups and stable and large Stokes shift along the variations of pH value can achieve rapid, label-free, and ionic-stable pH sensing with a wide sensing range from pH 1.8 to 13.6. The underlying mechanism of pH sensing is related to the protonation/deprotonation of -OH group of NGQDs, leading to the maximum pH-dependent luminescence peak shift along with the bandgap broadening or narrowing. In just 1 h, a single microplasma jet can produce a stable colloidal NGQD dispersion with 10 mg/mL concentration lasting for at least 100 pH detections, and the process is scalable. This approach is generic and opens new avenues for nanographene-based materials synthesis for applications in sensing, nanocatalysis, energy generation and conversion, quantum optoelectronics, bioimaging, and drug delivery.

Microplasma-Enabled Surfaced-Functionalized Silicon Quantum Dots for Label-Free Detection of Dopamine.

Rapid and sensitive detection of dopamine (DA) is important for the diagnostics of neurological disorders and the development of new drugs. Here, we report microplasma synthesis of surfaced-functionalized silicon quantum dots (SiQDs) at ambient conditions. The synthesized SiQDs with useful properties including abundant surface functionalities, stable colloidal dispersion, and photoluminescence (PL) emission enable direct label-free detection of DA, providing a wide sensing range from 0.83 to 83.33 μM and a low detection limit of 0.32 μM. Our work provides a new direction for the synthesis of colloidal SiQDs and the understanding of SiQD-based PL probes for biomolecule sensing.

Use of casein micelles to improve the solubility of hydrophobic pea proteins in aqueous solutions via low-temperature homogenization

The dairy industry struggles to maintain consumer attention in the midst of declining fluid milk sales. Current trends create an opportunity to incorporate plant-based proteins with milk to produce a high-protein, multisourced, functional food product. Plant-based proteins, such as those in peas, can be challenging to use in food systems because of their low solubility and undesirable off-flavors. Casein micelles have unique structural properties that allow for interactions with small ions and larger macromolecules that aid in their noteworthy ability as a nanovehicle for hydrophobic compounds. The objective of this study was to use the inherent structure of the casein micelle along with common dairy processing equipment to create a stable colloidal dispersion of casein micelles with pea protein to improve its solubility in aqueous solutions. We created 3 blends with varying ratios of casein-to-pea protein (90:10, 80:20, 50:50). We subjected the mixtures to 3 cycles of homogenization using a bench-top GEA 2-stage homogenizer at 27,580 kPa maintained at 4°C, followed by pasteurization at 63°C for 30 min. The resulting blends were homogeneous liquids with increased stability due to the lack of protein precipitation. Further protein analysis by HPLC and AA sequencing revealed that vicilin, an insoluble storage protein, was the main pea protein incorporated within the casein micelle structure. These results supported our hypothesis that low-temperature homogenization can successfully be used to create a colloidal dispersion with increased stability, in which insoluble plant-based proteins may be incorporated with casein micelles in an aqueous solution. Additionally, 3-dimensional microscope images of the blends indicated a noticeable difference between the surface roughness upon addition of pea protein to the casein micelle matrix. This research highlights a promising application for other plant-based proteins to be used within the dairy industry to help drive future product innovation while also meeting current processing conditions and consumer demands.

Zeta Potential and Colloidal Stability Predictions for Inorganic Nanoparticle Dispersions: Effects of Experimental Conditions and Electrokinetic Models on the Interpretation of Results

In this work, a set of experimental electrophoretic mobility (μe) data was used to show how inappropriate selection of the electrokinetic model used to calculate the zeta potential (ζ-potential) can compromise the interpretation of the results for nanoparticles (NPs). The main consequences of using ζ-potential values as criteria to indicate the colloidal stability of NP dispersions are discussed based on DLVO interaction energy predictions. For this, magnetite (Fe3O4) NPs were synthesized and characterized as a model system for performing electrokinetic experiments. The results showed that the Fe3O4 NPs formed mass fractal aggregates in solution, so the ζ-potential could not be determined under ideal conditions when μe depends on the NP radius. In addition, the Dukhin number (Du) estimated from potentiometric titration results indicated that stagnant layer conduction (SLC) could not be neglected for this system. The electrokinetic models that do not consider SLC grossly underestimated the ζ-potential values for the Fe3O4 NPs. The DLVO interaction energy predictions for the colloidal stability of the Fe3O4 NP dispersions also depended on the electrokinetic model used to calculate the ζ-potential. The results obtained for the Fe3O4 NP dispersions also suggested that, contrary to many reports in the literature, high ζ-potential values do not necessarily reflect high colloidal stability for charge-stabilized NP dispersions.

Performance of modified Schulze-Hardy rule on the stability of nano, micro, and macro colloidal dispersions: A comprehensive account

The Schulze–Hardy (S-H) rule that explains the precipitation (flocculation/coagulation) of colloid particles is almost 125 years old. This rule states that counter ions of the electrolytes are responsible for the precipitation of the charged colloids, and the charge on the counter ion determines the amount of the electrolyte required for the event. Though this is necessarily true, it does not take into account various other variables in the system viz. charges on the co-ions, the ionic strength of the solution, the charge density on the interacting ions, and that of the colloid particles, shape of the particles, etc. In this article, we have modified the S-H rule taking into account some of the above mentioned variables viz. the ionic strength of the solution, the charge density of the interacting ions as well as that of the associated colloid particles. We have attempted to find out the validity of the modified S-H rule on the nano, micro, and macro colloidal systems so far remaining unreported in the literature.

Carbon Dots From An Immunomodulatory Plant for Cancer Cell Imaging, Free Radical Scavenging and Metal Sensing Applications

Aim: This work aimed to develop Tinospora cordifolia stem-derived carbon dots (TCSCD) for cancer cell imaging, free radical scavenging and metal sensing applications. Method: The TCSCDs were synthesized by a simple, one-step, and ecofriendly hydrothermal carbonization method and characterized for their optical properties, morphology, hydrodynamic size, surface functionality, crystallinity, stability, bacterial biocompatibility, in vitro cellular imaging, free radical scavenging and metal sensing ability. Results: The TCSCDs exhibited excellent biocompatibility with dose-dependent bioimaging results in melanoma (B16F10) and cervical cancer (SiHa) cell lines. They exerted good free radical scavenging, Fe3+ sensing, bacterial biocompatibility, photostability, colloidal dispersion stability and thermal stability. Conclusion: The results reflect the potential of TCSCDs for biomedical and pharmaceutical applications.

Basic Concepts of Nanoemulsion and its Potential application in Pharmaceutical, Cosmeceutical and Nutraceutical fields

One of the widely efficient and noteworthy nanocarriers that could draw a great attention toward pharmaceutical fields is nanoemulsions (NEs). NEs are thermodynamically stable colloidal dispersions composed of two immiscible liquids, oil and water that mixed together using emulsifying agent (surfactant and co-surfactant). It regarded as pharmaceutical dosage form having droplet size within a nanometer range, hence it has extensively considered as carrier for delivering active agents. Such carrier is fabricated in order to overcome some obstacles associated with conventional drug delivery systems especially low bioavailability. The objective of this review is to present an overview about NE and its latest applications in diverse areas such as drug delivery, cosmeceutical and nutraceutical. Clarifications about different mechanisms of NEs development that are frequently used were provided. Correspondingly, popular characterization techniques for NEs such as determination of particle size, polydispersity index (PDI), zeta potential and viscosity were reviewed. Eventually, summary of physical and chemical instability in addition to the regulatory aspects of NE were provided.

Concurrent Enhancement of Conductivity and Stability in Water of Poly(3,4‐Ethylenedioxythiophene):Poly(Styrenesulfonate) Films Using an Oxetane Additive

AbstractPoly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is the most used conducting polymer in organic electronics and bioelectronics owing to its high conductivity combined with high optical transparency and availability as a stable colloidal aqueous dispersion, that can be processed as a conducting ink to produce thin and flexible films and electrodes. In this work, water‐resistant films of PEDOT:PSS showing enhanced conductivity are prepared by solely adding one reagent, 3‐methyl‐3‐oxetanemethanol, to PEDOT:PSS aqueous dispersions. The stability of the resultant thin films in water is attributed to the covalent cross‐linking of benzene rings anchored in PSS chains to polyether chains originated from the polymerization of oxetane groups, as indicated by NMR studies. A phase‐segregation within the PEDOT:cross‐linked PSS film is suggested to facilitate charge transport within the PEDOT network and to be at the origin of the improved conductivity. When immersed in water, the films exhibit increased water‐resistance towards resuspension and delamination and exhibit an increase of conductivity, by two to three orders of magnitude, depending on the used raw PEDOT:PSS formulation. The method described in this work is advantageous in originating water‐stable and highly conducting thin films of PEDOT:PSS as it does not involve high temperatures nor strong acids.

Microplasma-Tunable Graphene Quantum Dots for Ultrasensitive and Selective Detection of Cancer and Neurotransmitter Biomarkers.

The effective and precise detection of cancer and neurotransmitter biomarkers including folic acid (FA), dopamine (DA), and epinephrine (EP) are essential for early detection and diagnosis of cancer and neurological disorders and for the development of new drugs. However, it remains challenging to detect FA, DA, and EP with high selectivity and sensitivity with a single material. Herein, we report a photoluminescence (PL)-based selective sensing of FA, DA, and EP with nitrogen-doped graphene quantum dots (NGQDs) synthesized from biocompatible chitosan under ambient conditions using atmospheric pressure microplasmas. By regulating the pH, the selective detection is achieved in broad ranges from 0.8 to 80 μM for FA and 0.4 to 100 μM for both DA and EP with the very low limits of detections of 81.7, 57.8, and 16.7 nM for FA, DA, and EP, respectively. The developed PL sensing method shows the high throughput of 5000 detections per hour. Moreover, highly stable colloidal NGQD dispersion with 100 μg/mL concentration for at least 100 PL detections is produced in 1 h by a single microplasma, and the process is scalable. The mechanisms of the outstanding performance are related to the enhanced, size-dependent π-π stacking attraction between the NGQDs and the pH-regulated chemical states of the analytes and the associated pH-specific photo-induced electron transfer and PL.

3D Printing of MgAl2O4 Spinel Mesh and Densification Through Pressure-Less Sintering and Hot Isostatic Pressing.

MgAl2O4 spinel mesh with micro-features of 410 and 250 μm unit cell length and rib thickness, respectively, was three-dimensional (3D) printed and sintered followed by Hot Isostatic Pressing (HIPing). A stable colloidal dispersion of spinel in polymer-water solution was prepared and 3D-printed using a 30-gauge needle (∼100 μm inner diameter) on a regenHU 3D-Discovery bioprinter. Samples were characterized for their density and microstructure. Samples with near theoretical density after HIPing was subjected to mechanical property evaluation such as hardness by Vickers indentation and elastic modulus using nanoindentation technique. Microstructure of sintered samples across the ribs have shown graded grain structure with finer grains near the edges (0.7 μm average) with occasional porosity and coarser grains toward the center of the rib (5.2 μm average). HIPing resulted in substantial grain growth and the average grain size was found to be 10.9 μm (with a variation in the grain size of 2.2 μm along the edges and 13.1 μm at the center of the rib) exhibiting close packed and dense microstructure. Finer grains toward the edges may probably be due to the flow behavior during printing process and lower distribution of the powder loading along the edges resulting in low green density. This relatively higher porosity pining the grain growth under the extremely low heating rate employed for the controlled shrinkage to maintain the integrity of the sample. 3D printed samples after HIPing exhibited a density of 3.57 g/cc and hardness of 12.95 GPa, which are at par with the samples processed through conventional ceramic processing techniques. Nanoindentation studies employing maximum load of 45 mN with depth have shown an elastic modulus of 238 ± 15 GPa. MgAl2O4 spinel mesh 3D printed in this study is a potential prospective candidate that can be explored for cranioplasty procedures and other biomedical applications.

Metal-Free Antibacterial Additives Based on Graphene Materials and Salicylic Acid: From the Bench to Fabric Applications.

The custom functionalization of a graphene surface allows access to engineered nanomaterials with improved colloidal stability and tailored specific properties, which are available to be employed in a wide range of applications ranging from materials to life science. The high surface area and their intrinsic physical and biological properties make reduced graphene oxide and graphene oxide unique materials for the custom functionalization with bioactive molecules by exploiting different surface chemistries. In this work, preparation (on the gram scale) of reduced graphene oxide and graphene oxide derivatives functionalized with the well-known antibacterial agent salicylic acid is reported. The salicylic acid functionalities offered a stable colloidal dispersion and, in addition, homogeneous absorption on a sample of textile manufacture (i.e., cotton fabrics), as shown by a Raman spectroscopy study, thus providing nanoengineered materials with significant antibacterial activity toward different strains of microorganisms. Surprisingly, graphene surface functionalization also ensured resistance to detergent washing treatments as verified on a model system using the quartz crystal microbalance technique. Therefore, our findings paved the way for the development of antibacterial additives for cotton fabrics in the absence of metal components, thus limiting undesirable side effects.