Amine-functionalized Graphene Research Articles

Enhanced Cr(VI) removal via CPBr-modified MIL-88A@amine-functionalized GO: synthesis, performance, and mechanism.

Water contamination by heavy metals, especially chromium (VI), poses a critical environmental issue due to its carcinogenic nature and persistence in the environment. Addressing this, the current study develops an efficient adsorbent, CPBr-MIL-88A@AmGO, which utilizes the synergistic capabilities of Cetylpyridinium bromide-modified MIL-88A and amine-functionalized graphene oxide to enhance Cr(VI) removal from aqueous solutions. The obtained results indicate that CPBr-MIL-88A@AmGO achieves its highest removal efficacy at pH 2, where the interaction of CPBr and AmGO's positively charged centers significantly contributes to the adsorption processes. According to the Langmuir isotherm model, the composite's adsorption capacity reached a maximum of 306.75 mg/g. The adsorption kinetics adhered to a pseudo-second-order model along with the endothermic nature of the process. Although the presence of SO42- ions significantly reduces adsorption capacity, other interfering ions including Na+, K+, Ca2+, Cl-, and NO3- only slightly affect it. Remarkably, the composite maintains high removal efficiency, over 82%, even after 7 recycling tests, underscoring its potential for practical applications in water treatment systems. The proposed mechanism involves the contribution of electrostatic attractions, ion exchange, complexation, and the reduction of Cr(VI) to Cr(III) in the removal process. This study not only offers a potent solution for Cr(VI) remediation but also contributes to sustainable water resource management.

Enhanced Mechanical Properties of Carbon Fiber/Epoxy Nanocomposites Modified with Amine-Functionalized Graphene

<div>Since the beginning of time, people have desired the best materials for production. Metals are often too heavy to be used in manufacturing. Polymer matrix composites (PMC) can be considered more dependable than metals in practical applications because of their high strength-to-weight ratio so it is a good alternative of metals. The article’s objective is to investigate the various PMC properties that are reinforced with carbon fiber. CFRP (Carbon fiber-reinforced polymer) was first made using the hand layup method with carbon fiber as a reinforcement and epoxy resin as a matrix after a thorough literature review. As CFRP have higher stiffness and superior “strength-to-weight ratio,” fiber-reinforced polymer (FRP) composites perform notably better than various conventional metallic materials. The qualities of the matrix can be changed to enhance the characterization of FRP composites. The mechanical qualities of FRP composites have risen as a result of significant advancements in the application of nanoparticles for betterment of the matrix and various tests were conducted to calculate the properties of the composite.</div>

Taking a Tailored Approach to Material Design: A Mechanistic Study of the Selective Localization of Phase-Separated Graphene Microdomains.

To achieve multifunctional properties using nanocomposites, selectively locating nanofillers in specific areas by tailoring a mixture of two immiscible polymers has been widely investigated. Forming a phase-separated structure from entirely miscible molecules is rarely reported, and the related mechanisms to govern the formation of assemblies from molecules have not been fully resolved. In this work, a novel method and the underlying mechanism to fabricate self-assembling, bicontinuous, biphasic structures with localized domains made up of amine-functionalized graphene nanoplatelets are presented, involving the tailoring of compositions in a liquid processable multicomponent epoxy blend. Kinetics studies were carried out to investigate the differences in reactivity of various epoxy-hardener pairs. Molecular dynamics simulations and in situ optical photothermal infrared spectroscopy measurements revealed the trajectories of different components during the early stages of polymerization, supporting the migration (phase behavior) of each component during the curing process. Confirmed by the phase structure and the correlated chemical maps down to the submicrometer level, it is believed that the bicontinuous phase separation is driven by the change of the miscibility between various building blocks forming during polymerization, leading to the formation of nanofiller domains. The proposed morphology evolution mechanism is based on combining solubility parameter calculations with kinetics studies, and preliminary experiments are performed to validate the applicability of the mechanism of selectively locating nanofillers in the phase-separated structure. This provides a simple yet sophisticated engineering model and a roadmap to a mechanism for fabricating phase-separated structures with nanofiller domains in nanocomposite films.

Amine functionalised graphene embedded polyvinyl alcohol (PVA) and PVA-chitosan hydrogel composites

A novel amine-functionalized graphene oxide (AFG) doped polyvinyl alcohol (PVA)/chitosan (PVA-Ch) composite film was developed using an eco-synthesis approach, eliminating the need for halogenated compounds. The resulting AFG-doped PVA/Chitosan (PVA-Ch/AFG) polymer film exhibited promising properties for controlled delivery and biosensing applications. The investigation included assessing the swelling behaviour, dissolution percent, gel fraction, and mechanical properties of the polymer film. The swelling characteristics of PVA-Ch and PVA-Ch/AFG were found to be pH and temperature-dependent across various pH ranges (3, 5, 7, and 9). Interestingly, PVA-Ch/AFG demonstrated a stable swelling pattern at pH 5 and 7, unaffected by changes in chitosan concentration, indicating enhanced stability compared to PVA-Ch. The study also explored the use of PVA-Ch/AFG in a drug delivery system, revealing controlled release of the model antibiotic amphicillin, emphasizing its potential in medical applications. Furthermore, the eco-friendly synthesis route underscored the safety of PVA-Ch/AFG for use in food and medical applications. Biocompatibility assessments, including biodegradability studies and cytotoxicity tests on fibroblasts (3T3 cells), confirmed the safety profile of PVA-Ch/AFG. In conclusion, the study suggests that PVA-Ch/AFG holds promise for bio-sensing applications, offering a flexible and colorimetric platform capable of encapsulating, adsorbing, and desorbing biomolecules such as drugs and sensing compounds.

Spray coating vapor-phase interfacial polymerization: A new approach for developing 2D nanosheet enabled thin film nanocomposite membranes to remove heavy metal ions

Alternate to the conventional dip coating method, a new eco-friendly approach has been used to develop thin-film nanocomposite (TFN) membranes in this research work, all while preserving the exceptional separation capabilities of TFN membranes. The methodology is altered by employing spray coating and implementing vapor-phase interfacial polymerization (VP-IP) to craft thin-film nanocomposite membranes. This innovative approach significantly reduces reagent consumption and eliminates the need for organic solvent (n-hexane). By incorporating amine-functionalized graphene oxide (GO-NH-NH2) as a nanofiller, we have fabricated both thin-film nanocomposite (TFN) and thin-film composite (TFC, without nanofiller) membranes. Developed membranes were characterized with various physicochemical characterization techniques and tested against heavy metal ions. The membranes demonstrated outstanding performance, with ∼ 96 % rejection of Na2SO4, ∼95 % rejection of Pb(NO3)2, ∼94 % rejection of CuSO4, and ∼ 92 % rejection of CdSO4 salt with highest pure water flux 46.57 Lm2h−1. The antifouling characteristics and antibacterial activity of the membrane were also assessed, revealing that including nanosheets has substantially elevated the antifouling properties, notably by increasing the flux recovery ratio. Furthermore, the prepared membranes exhibited enhanced antibacterial performance after incorporating these nanosheets.

A study on photocatalytic Janus membrane reactor for direct conversion of low concentration carbon dioxide in air to methane: Effects of combination of two-dimensional carbon nanosheets

Large CO2 emissions cause the greenhouse effect, which threatens human survival. Directly converting CO2 in the air into energy and valuable resources is the most effective way to address the greenhouse effect. Currently, the main problem with CO2 conversion is the poor conversion efficiency owing to low CO2 concentrations in the air. In this study, a Janus membrane with the functions of concentrating CO2 (gas separation layer) and photocatalytic reaction (photocatalytic reaction layer) was fabricated. The Janus membrane directly converted extremely low concentrations of CO2 in the air into CH4. Amine-functionalized graphene oxide was added to regulate the CO2 conversion efficiency and the structure of the gas separation layer. Graphene was added to the photocatalytic reaction layer to suppress electron-hole recombination and increase the probability of excited electrons colliding with CO2. The experimental results showed that the modification of the gas separation layer or the photocatalytic reaction layer effectively increased the CH4 yield of the Janus membrane. By maintaining a balance between the selectivity and permeability coefficients of the gas separation layer, the highest methane yield (8.9 ppm) was obtained. The CH4 yield of the Janus membrane was further improved (8.9 ppm to 11.1 ppm) by modifying the photocatalytic reaction layer with graphene. This study proposes a feasible method for improving the efficiency of the Janus membrane for converting low-concentration CO2 in air to CH4.

Thermal Effects on Electrochemical Performance of Copper Oxide Nanoparticles Decorated Amine-Functionalized Graphene Oxide for Ultrahigh Energy Density Supercapacitor with Real-Life Application

Thermal Effects on Electrochemical Performance of Copper Oxide Nanoparticles Decorated Amine-Functionalized Graphene Oxide for Ultrahigh Energy Density Supercapacitor with Real-Life Application

Optimal hybrid artificial intelligence models for predicting the adsorptive removal of dyes and phenols from aqueous solutions using an amine-functionalized graphene oxide/layered triple hydroxide nanocomposite

Water pollution is a serious environmental problem with a significant negative impact on human health and the ecosystem. Adsorption is an attractive process for water decontamination. Developing artificial intelligence models capable of predicting the adsorption performance of newly developed materials could save huge amounts of resources and efforts. In the present study, a novel polyethyleneimine/graphene oxide/layered triple hydroxide (PEI/GO/LTH) nanocomposite was synthesized, characterized, and applied to adoptively remove harmful phenolic (bisphenol A) and azo dye (acid red 1) from wastewater samples. The results revealed that the PEI/GO/LTH nanocomposite is highly effective in removing these two pollutants. The adsorption isotherms and kinetics of these two pollutants are best fitted by the Langmuir isotherm and pseudo-second-order models, respectively. Additionally, the synthesized nanocomposite is easily and highly regenerable with an insignificant loss in performance when repeatedly used. Besides the above investigations, the present study also employs support vector machines (SVM) and Bayesian optimization as tools for predicting the adsorptive removal of acid red 1 (AR1) dye and bisphenol A (BPA) from contaminated water samples by the synthesized PEI/GO/LTH nanocomposite. The models achieved promising results as the correlation coefficients, during the testing phase, reached 97.3 and 96.6 % for the AR1 and BPA data using BO-SVM models, respectively.

Probing interaction of atherogenic lysophosphatidylcholine with functionalized graphene nanosheets: theoretical modelling and experimental validation.

The potential of graphene derivatives for theranostic applications depends on their compatibility with cellular and biomolecular components. Lysophosphatidylcholine (LPC), a lipid component present in oxidized low-density lipoproteins, microvesicles and free circulation in blood, plays a critical role in the pathophysiology of various diseases. Usingdensity functional theory-based methods, we systematically investigated the interaction of atherogenic LPC molecule with different derivatives of graphene, including pristine graphene, graphene with defect, N-doped graphene, amine-functionalized graphene, various graphene oxides and hydroxylated graphene oxides. We observed that the adsorption of LPC on graphene derivatives is highly selective based on the orientation of the functional groups of LPC interacting with the surface of the derivatives. Hydroxylated graphene oxide exhibited the strongest interaction with LPC with adsorption energy of - 2.1 eV due to the interaction between the hydroxyl group on graphene and the phosphate group of LPC. The presence of aqueous medium further enhanced this interaction indicating favourable adsorption of LPC and graphene oxide in biological systems. Such strong interaction leads to substantial change in the electronic structure of the LPC molecule, which results in the activation of this molecule. In contrast, amine-modified graphene showed the least interaction. These theoretical results are in line with our experimental fluorescence spectroscopic data of LPC/1-anilino-8-napthalene sulfonic acid complex. Our present comprehensive investigation employing both theoretical and experimental methods provides a deeper understanding of graphene-lipid interaction, which holds paramount importance in the design and fabrication of graphene-based nanomaterials for biomedical applications. In this study, we employed the density functional theory-based methods to investigate the electronic and structural properties of graphene derivatives and LPC molecule using the Quantum Espresso package. The exchange-correlation functional was described within generalized gradient approximation (GGA) as parameterized by Perdew, Burke and Ernzerhof (PBE). The valence electrons were represented using plane wave basis sets. `The Grimme's dispersion method was used to include the van der Waals dispersion correction.

Effects of different amine-functionalized graphene oxide on the mechanical and thermal properties of polyimide composites

The utilization of functionalized graphene oxide as nanofillers has attracted significant attention in the development of high-performance composite materials. In this study, amine-functionalized graphene oxide (AFGO) by different amines, including p-phenylenediamine- (PPD-GO) and 4, 4’-diaminodiphenyl ether (ODA-GO), respectively, was prepared and used to synthesize a series of polyimide (PI) composite membranes via in situ polymerization method. The PPD-GO/PI and ODA-GO/PI composite membranes exhibited much higher mechanical and thermal properties than that of neat PI, owing to the diverse interfacial interaction and the surface architecture behavior. Compared to neat PI, the tensile strengths were enhanced 14.6% and 14.5%, the tensile modulus were enhanced 26.9% and 23.2%, and the Tg increased by 9°C and 17.5°C of the PI composite membrane containing 0.3 wt% PPD-GO or ODA-GO, respectively. This study provides a guidance for the development of high-performance PI composite materials through the regulated interfacial structure via the moderate chain length.

Thin film nanocomposite polyamide membrane doped with amino-functionalized graphene quantum dots for organic solvent nanofiltration

Thin film nanocomposite (TFN) organic solvent nanofiltration (OSN) membrane with improved separation performance was fabricated via interfacial polymerization reaction between amine-functionalized graphene quantum dots (af-GQDs) doped aqueous monomer solution of m-phenylenediamine (MPD) and n-hexane solution containing trimesoyl chloride (TMC) monomer. We emphasize the employment of extra-low content for both af-GQDs and MPD, so that we could maximize the function of these nanomaterials and eliminate their aggregation at the same time. The af-GQDs nanomaterials could regulate the interfacial polymerization process and could be strongly anchored in the polyamide film via covalent bonding, hence could prevent their loss while providing more channels for faster solvent penetration. As a result, the optimized OSN membrane, TFN-50, shows a super-smooth surface, with a surface roughness as low as 4.3 ± 0.2 nm, and excellent pure solvent permeances which reach 135.8, 112.7, and 69.8 L m−2 h−1 MPa−1 for methanol, DMF and ethanol, respectively, as well as a very high Rhodamine B (RDB, 479 Da) rejection of up to 99.2%, and an ethanol permeance of 61.4 L m−2 h−1 MPa−1. Furthermore, the TFN-50 OSN membrane still shows excellent filtration performance after being submerged in DMF for 336 h or continuous crossflow filtration with Rose bengal (RB, 1017 Da)/DMF solution for 136 h, demonstrating its excellent solvent resistance.

Amine-functionalized graphene oxide in polyamine based drilling fluids for nanosized pore plug filter cake

Water-based muds (WBM) is widely used in oil and gas wells drilling industry due to its environmental friendliness and lower operational cost implication. However, WBM drilling process has severe shale swelling problems caused by the hydration due to the shale minerals affinity to water from the WBM which reduces WBM technical performance. Thus, additives that fitted to its function should be added in WBM formulations to enhance overall drilling performance to achieve the target depth. In this study, graphene oxide (GO) is selected as the additive due to its excellent physico-chemical properties could benefit as an option to mitigate the above challenges. GO was synthesized via Modified Hummers' method where the average thickness obtained was ±46 nm. The GO additive was then modified with Octadecylamine (ODA) to alter the surface hydrophobicity. The contact angle of GO changed from 25° ± 0.5 to 98.9° ± 1.8 after the ODA modification. The hydrophobic GO (HGO) was then added in the drilling fluid formulation and the drilling fluid performance was evaluated based on filtration characteristics. The filter cake showed a thickness of 0.832 mm and a filtrate volume of 5.09 ml at 150 psi/30 min after the filtration with drilling fluid treated with HGO. The filter cake formed was the thinnest and the least filtrate volume was produced which are 30% and 20% reductions compared to drilling fluid without GO, which signify the remarkable reduction of fluid loss. On top of that, the drilling fluid with HGO demonstrated a good rheology property over wide shear rate scheme and enhanced thermal stability. Hence, GO was highly recommended as a potential fluid loss control nano-additive in drilling fluid formulation.

Enhancing Polysulfone Mixed-Matrix Membranes with Amine-Functionalized Graphene Oxide for Air Dehumidification and Water Treatment.

Porous low-pressure membranes have been used as active membranes in water treatment and as support for thin-film composite membranes used in water desalination and gas separation applications. In this article, microfiltration polysulfone (PSf)mixed-matrix membranes (MMM) containing amine-functionalized graphene oxide (GO-NH2) were fabricated via a phase inversion process and characterized using XPS, SEM, AFM, DMA, XRD, and contact angle measurements. The effect of GO-NH2 concentration on membrane morphology, hydrophilicity, mechanical properties, and oil-water separation performance was analyzed. Significant enhancements in membrane hydrophilicity, porosity, mechanical properties, permeability, and selectivity were achieved at very low GO-NH2 concentrations (0.05-0.2 wt.%). In particular, the water permeability of the membrane containing 0.2 wt.% GO-NH2 was 92% higher than the pure PSf membrane, and the oil rejection reached 95.6% compared to 91.7% for the pure PSf membrane. The membrane stiffness was also increased by 98% compared to the pure PSf membrane. Importantly, the antifouling characteristics of the PSf-GO-NH2 MMMs were significantly improved. When filtering 100 ppm bovine serum albumin (BSA) solution, the PSf-GO-NH2 MMMs demonstrated a slower flux decline and an impressive flux recovery after washing. Notably, the control membrane showed a flux recovery of only 69%, while the membrane with 0.2 wt.% GO-NH2 demonstrated an exceptional flux recovery of 88%. Furthermore, the membranes exhibited enhanced humidity removal performance, with a permeance increase from 13,710 to 16,408. These results indicate that the PSf-GO-NH2 MMM is an excellent candidate for reliable oil-water separation and humidity control applications, with notable improvements in antifouling performance.

Experimental investigation and characterization of the tensile and flexural properties of amine functionalized graphene enhanced nanocomposite prepregs

Graphene has drawn tremendous scientific and commercial interest because of its outstanding properties. It is extensively researched as a reinforcement in composite materials. Graphene is the most significant reinforced filler because of its outstanding mechanical, electrical, and thermal properties. On the other hand, epoxy resin is highly utilized in practical applications such as laminates, coatings, and composites because of its simplicity of processing, firm adherence to various substrates, and chemical resistance. The distribution and interplay of graphene nanoparticles with the polymer determine the composite's performance. Several approaches are used to integrate Graphene into graphene-enhanced composites, including graphene dispersion in the polymer matrix. Prepregs are used in high-performance applications where weight and mechanical qualities are more important than price. Prepreg constructions frequently employ premium epoxy resins, carbon fiber, or other cutting-edge fibers. This research aims to experimentally investigate the tensile and flexural properties of epoxy prepreg composite with a varied weight percentage of amine-functionalized Graphene. In this research, to have good dispersion of Amine functionalized Graphene, the developed methodology with a combination of different stages for better dispersion. The Effect of different concentrations of weight fractions (wt. %) of Amine functionalized Graphene (AFG) was tested through tensile strength, and flexural strength surface fractures were investigated through Scanning Electron Microscope (SEM). The result of the tensile test and flexural test exhibited the enhancement of Tensile strength by 12.33% at one wt. % of AFG as a reinforcement and flexural strength, no change was seen compared to neat Epoxy.

Single step synthesis of amine functionalized graphene oxide/Cu-Ni bimetallic nanocomposite and tuning its electrical properties

A facile chemical method was adopted for the synthesis of bimetallic Cu-Ni particles supported on amine-functionalized graphene oxide (AGO). The amine functionalized graphene oxide (AGO) and different nanocomposites were characterized by X-ray photoelectron spectroscopy,which indicated that Cu and Ni nanoparticles were partially oxidized on the surface layer AGO.The optical direct bandgap of AGO and its nanocomposite were in the range of 5.1–5.6 eV. The PL emission spectra of these nanocomposites showed different defects related to PL emission peaks.The interaction between the metal oxide and GO was calculated from the Perdew-Becke-Ernzeroff density functional theory and from the results it is observed thatmetal oxides were adsorbed on the GO surface, and the cation-π interaction was responsible for the most stable orientation. Electrical conductivity and relaxation were significantly pronounced in low/mid-temperature zones. Moreover, AGO-Cu/Ni (1:0) showed the highest conductivity and excellent efficiency and may be used as potential candidate for smart electrical device fabrication.

Amine-functionalized graphene quantum dots–hyaluronic acid nanocomposite as a high-resolution cancer cell bioimaging and biosensing system

Amine-functionalized graphene quantum dots–hyaluronic acid nanocomposite as a high-resolution cancer cell bioimaging and biosensing system

Design and introduction of quaternary ammonium hydroxide‐functionalized graphene oxide quantum dots as a pseudo-homogeneous catalyst for epoxidation of α,β-unsaturated ketones

In present work, design and synthesis of a novel pseudo-homogeneous catalyst is described. For this purpose, amine-functionalized graphene oxide quantum dots (N-GOQDs) were prepared from graphene oxide (GO) by a facile one-step oxidative fragmentation approach. The prepared N-GOQDs were then modified with quaternary ammonium hydroxide groups. Various characterization techniques clearly revealed that the quaternary ammonium hydroxide‐functionalized GOQDs (N-GOQDs/OH−) have been successfully synthesized. TEM image revealed that the GOQDs particles are almost regularly spherical in shape and mono-dispersed with particle sizes < 10 nm. The efficiency of the synthesized N-GOQDs/OH− as a pseudo-homogeneous catalyst in epoxidation of α,β-unsaturated ketones in the presence of aqueous H2O2 as an oxidant at room temperature was investigated. The corresponding epoxide products were obtained in good to high yields. This procedure has the advantages of a green oxidant, high yields, involvement of non-toxic reagents and reusability of the catalyst without discernible loss in activity.

Evaluation of Thermophysical Properties and Thermal Performance of Amine-Functionalized Graphene Oxide/Deep Eutectic Solvent Nanofluids as Heat-Transfer Media for Desalination Systems

The study mainly focuses on the synthesis and characterization of amine-functionalized graphene oxide (GO-NH2) nanoparticles. It also reports the thermal properties and stability analysis of deep eutectic solvent (DES)- and GO-NH2- based nanofluids. DES is composed of diphenyl ether as the hydrogen bond acceptor and DL-menthol as the hydrogen bond donor in the molar ratio 1:1. The nanofluid was prepared by a two-step method where two different concentrations of functionalized graphene nanofluids, namely, 0.0033 volume fraction (NF1) and 0.0101 volume fraction (NF2), were reported. XRD and FTIR analyses were used to validate the nanoparticle’s identity. Additionally, the morphology and composition of GO-NH2 nanoparticles were investigated using FESEM, FETEM, EDS, and Raman analyses. After that, the stability of the nanofluids was assessed using ζ potential measurements. The ζ potential measurements revealed increased stability, indicating that no agglomeration occurred in the DES-based nanofluid. Excellent thermal conductivity enhancement was observed at a higher temperature for the GO-NH2 nanofluid. The density and viscosity of the base fluid and nanofluid decreased with an increase in temperature from 25 to 85 °C. Further, the specific heat capacity of the nanofluids also increased with the increase in temperature and volume fractions of the nanofluid. Thermogravimetric analysis was also performed to evaluate the thermal degradation of the nanofluid under a nitrogen atmosphere. The nanofluid was used in brine recirculation multistage flash desalination where the gained output ratio of less than 10 was obtained through ASPEN simulation.

Interfacial Engineering of PVDF‐TrFE toward Higher Piezoelectric, Ferroelectric, and Dielectric Performance for Sensing and Energy Harvesting Applications

The electrical properties of pristine fluoropolymers are inferior due to their low polar crystalline phase content and rigid dipoles that tend to retain their fixed moment and orientation. Several strategies, such as electrospinning, electrohydrodynamic pulling, and template-assisted growing, have been proven to enhance the electrical properties of fluoropolymers; however, these techniques are mostly very hard to scale-up and expensive. Here, a facile interfacial engineering approach based on amine-functionalized graphene oxide (AGO) is proposed to manipulate the intermolecular interactions in poly(vinylidenefluoride-trifluoroethylene) (PVDF-TrFE) to induce β-phase formation, enlarge the lamellae dimensions, and align the micro-dipoles. The coexistence of primary amine and hydroxyl groups on AGO nanosheets offers strong hydrogen bonding with fluorine atoms, which facilitates domain alignment, resulting in an exceptional remnant polarization of 11.3µCcm-2 . PVDF-TrFE films with 0.1wt.% AGO demonstrate voltage coefficient, energy density, and energy-harvesting figure of merit values of 0.30VmN-1 , 4.75Jcm-3 , and 14pm3 J-1 , respectively, making it outstanding compared with state-of-the-art ceramic-free ferroelectric films. It is believed that this work can open-up new insights toward structural and morphological tailoring of fluoropolymers to enhance their electrical and electromechanical performance and pave the way for their industrial deployment in next-generation wearables and human-machine interfaces.

Nanocomposite films as electrochemical sensors for detection of catalase activity.

Cross-linked hydrogel substrates have garnered attention as they simultaneously enable oxidoreductase reactions in a control volume extended to adsorption of redox capacitors for amplification of electrochemical signals. In this study, the effect of catalase immobilization in mold-casted alginate-based thin films (1 mm × 6 mm × 10 mm) containing multi walled carbon nanotubes (MWCNT) coated with chitosan has been studied via amperometry. The amperometric response was measured as a function of peroxide concentration, at a fixed potential of −0.4 V vs. SPCE in phosphate-buffered saline (pH = 7.4). Results indicate substrate detection is not diffusion-limited by the 100 μm thick chitosan layer, if the cationic polyelectrolyte is in contact with the sensing carbon electrode, and the linear detection of the enzyme absent in solution is enabled by immobilization (R 2 = 0.9615). The ferricyanide-mediated biosensor exhibited a sensitivity of 4.55 μA/mM for the optimal formulation at room temperature comparable to other nanomaterial hybrid sensing solution namely amine-functionalized graphene with an average response time of 5 s for the optimal formulation. The suitability of the optimized chitosan-coated alginate slabs nano-environment for co-encapsulation of catalase and carbon nanotubes was confirmed by cyclic voltammetry.