Efficient CO2 Conversion through a Novel Dual-Fiber Reactor System.

Carbon dioxide (CO2) can be converted to valuable organic chemicals using light irradiation and photocatalysis. Today, light-energy loss, poor conversion efficiency, and low quantum efficiency (QE) hamper the application of photocatalytic CO2 reduction. To overcome these drawbacks, we developed an efficient photocatalytic reactor platform for producing formic acid (HCOOH) by coating an iron-based metal-organic framework (Fe-MOF) onto side-emitting polymeric optical fibers (POFs) and using hollow-fiber membranes (HFMs) to deliver bubble-free CO2. The photocatalyst, Fe-MOF with amine-group (-NH2) decoration, provided exceptional dissolved inorganic carbon (DIC) absorption. The dual-fiber system gave a CO2-to-HCOOH conversion rate of 116 ± 1.2 mM h-1 g-1, which is ≥18-fold higher than the rates in photocatalytic slurry systems. The 12% QE obtained using the POF was 18-fold greater than the QE obtained by a photocatalytic slurry. The conversion efficiency and product selectivity of CO2-to-HCOOH were up to 22 and 99%, respectively. Due to the dual efficiencies of bubble-free CO2 delivery and the high QE achieved using the POF platform, the dual-fiber system had energy consumption of only 0.60 ± 0.05 kWh mol-1, 3000-fold better than photocatalysis using slurry-based systems. This innovative dual-fiber design enables efficient CO2 valorization without the use of platinum group metals or rare earth elements.

Nanocomposite of Nickel Nanoparticles-Impregnated Biochar from Palm Leaves as Highly Active and Magnetic Photocatalyst for Methyl Violet Photocatalytic Oxidation.

Photocatalysis has been recognized as a feasible method in water and wastewater treatment. Compared to other methods such as adsorption and chemical oxidation, the use of photocatalyst in the advanced oxidation processes gives benefits such as a longer lifetime of the catalyst and less consumable chemicals. Currently, explorations into low-cost, effective photocatalysts for organic contaminated water are being developed. Within this scheme, an easily separated photocatalyst with other functionality, such as high adsorption, is important. In this research, preparation of a magnetic nanocomposite photocatalyst based on agricultural waste, palm leaves biochar impregnated nickel nanoparticles (Ni/BC), was investigated. The nanocomposite was prepared by direct pyrolysis of palm leaves impregnated with nickel (II) chloride precursor. Furthermore, the physicochemical characterization of the material was performed by using an X-ray diffractometer (XRD), scanning electron microscopy-energy dispersive X-ray fluorescence (SEM-EDX), transmission electron microscopy (TEM), gas sorption analysis, X-ray photoelectron spectroscopy (XPS) and vibrating sample magnetometer (VSM). The photocatalytic activity of Ni/BC was evaluated for methyl violet (MV) photocatalytic oxidation. The results from XRD, XPS and TEM analyses identified single nickel nanoparticles dispersed on the biochar structure ranging from 30-50 nm in size. The dispersed nickel nanoparticles increased the BET specific surface area of biochar from 3.92 m2/g to 74.12 m2/g oxidation. High photocatalytic activity of the Ni/BC was exhibited by complete MV removal in 30 min for the concentration ranging from 10-80 mg/L. In addition, the Ni/BC showed stability in the pH range of 4-10 and reusability without any activity change until fifth usage. The separable photocatalyst is related to magnetism of about 13.7 emu/g. The results highlighted the role of biochar as effective support for Ni as photoactive material.

Femtomolar Detection of Dengue Virus DNA with Serotype Identification Ability.

Dengue surveillance trusts only on reverse transcription-polymerase chain reaction (RT-PCR) type methodologies for confirmation of dengue virus serotypes; however, its real time application is restricted due to the expensive, complicated, and time-consuming process. In search of a new sensing system, here, we have reported a two-way-detection method for Dengue virus (DENV) serotype identification along with DNA quantification by using a new class of nanocomposite of gold nanoparticles (AuNP) and nitrogen, sulfur codoped graphene quantum dots (N,S-GQDs). The N,S-GQDs@AuNP has been used for serotype detection via a simple fluorescence technique using four dye-combined probe DNAs which is further validated by confocal microscopy. The quantification of the DNA has been measured by the differential pulse voltammetric (DPV) technique using methyelene blue as a redox indicator. Results obtained in this study, clearly demonstrate that the N,S-GQDs@AuNP can efficiently detect the four serotypes of DENV individually in the concentration range of 10-14 to 10-6 M with the LOD of 9.4 fM. In addition, to confirm its applicability in long chained complex DNA system, the sensor was also applied to the clinically isolated DENV DNA and showed satisfactory performances for serotype identification as well as quantification. We hope this simple and reliable method can pave an avenue for the development of sensitive and robust sensing probes in biomedical applications.

Significance of Early and Late Stages of Coupled Aggregation and Sedimentation in the Fate of Nanoparticles: Measurement and Modeling.

Despite aggregation's crucial role in controlling the environmental fate of nanoparticles (NP), the extent to which current models can describe the progressive stages of NP aggregation/sedimentation is still unclear. In this paper, 24 model combinations of two population-balance models and various collision frequency and settling velocity models are used to analyze spatiotemporal variations in the size and concentration of hydroxyapatite (HAp) NP. The impact of initial conditions and variability in attachment efficiency, α, with aggregate size are investigated. Although permeability models perform well in calculating collision frequencies, they are not appropriate for describing settling velocity because of their negative correlation or insensitivity in respect to fractal dimension. Considering both early and late stages of aggregation, both experimental and model data indicate overall mass removal peaks at an intermediate ionic strength (5 mM CaCl2) even though the mean aggregate size continued to increase through higher ionic strengths (to 10 mM CaCl2). This trend was consistent when different approaches to the initial particle size distribution were used and when a variable or constant α was used. These results point to the importance of accurately considering different stages of aggregation in modeling NP fate within various environmental conditions.

Functionalized N-doped graphene quantum dots for electrochemical determination of cholesterol through host-guest inclusion.

Functionalized nitrogen-doped graphene quantum dots (N-GQD) with mean particle size of 8.5 ± 0.5 nm were covalently linked to ß-cyclodextrin (ß-CD) to form a ß-CD@N-GQD nanoprobe. The probe is shown to enable voltammetric determination of cholesterol via selective host-guest recognition and by using ferrocene (FC) as the redox indicator. FC is first included in ß-cyclodextrin. Cholesterol has a higher affinity for ß-CD (in comparison to FC). It forms a strong inclusion complex with ß-CD and can replace FC from its cavities. The quantity of released FC is proportional to the concentration of cholesterol. The differential pulse voltammetric signal for FC (with a peak at typically 0.22 V vs Ag/AgCl) increases linearly in the 0.5-100 µM cholesterol concentration range, with a limit of detection as low as 80 nM. The assay is found to be highly selective over 15 potentially interfering species. The method was successfully applied to the detection of cholesterol in spiked serum samples which gave recoveries between 96 and 101%. The probe can be stored for at least 28 days after which the activity still is 87%. Graphical abstract This scheme illustrates the detection of cholesterol by differential pulse voltammetry (DPV) technique. The ß-cyclodextrin functionalized nitrogen-doped graphene quantum dot (ß-CD@N-GQD) probe was developed to enable voltammetric determination of cholesterol using selective host-guest recognition.

Label-Free and Nondestructive Separation Technique for Isolation of Targeted DNA from DNA-Protein Mixture Using Magnetic Au-Fe3O4 Nanoprobes.

The interest in DNA-protein-based diagnostics has recently been growing enormously, which makes the separation process of DNA or protein from a cell extract extremely important. Unlike the traditional separation process, a novel approach is in demand which can nondestructively isolate the target biomolecules without sacrificing the other components in the mixture. In this study, we have demonstrated a new and simple separation technique by using well-established bifunctional Au-Fe3O4 nanocomposites as the separation nanoprobes to efficiently isolate the specifically targeted nanomolar concentrated DNA over 70% from its associate DNA-protein mixture in the presence of a magnetic field. The sensing accuracy of both as-separated DNA and protein are quantitatively examined by UV-vis spectroscopy, and then qualitatively validated by gel analysis. Results obtained in this study clearly demonstrated that this newly developed separation procedure not only provides the efficient separation for the targeted DNA but can also maintain the bioactivity of as-separated protein and DNA solutions. The superiority of this technique can open an avenue to establish a label-free and nondestructive platform for a wide variety of biomolecule separation applications.

Simultaneous achievement of energy recovery and carbon sequestration through municipal solid waste management: A review.

Effective municipal solid waste (MSW) management is a crucial component for sustainable cities, as inefficient waste disposal contributes to the release of about a billion tons of CO2-eq in greenhouse gases (GHG) annually. With escalating global waste generation, there is an untapped opportunity to integrate carbon dioxide removal (CDR) technologies into existing MSW management processes. This review explores current research on utilizing MSW for CDR, emphasizing its potential for both energy generation and carbon sequestration. The investigation covers three waste management practices: landfilling, waste-to-energy (WtE), and biochar production, revealing two paths for carbon sequestration. First, MSW serves as a feedstock in bioenergy with carbon capture and storage (BECCS), acting as a carbon-neutral resource that avoids fossil fuel and energy crop use, reducing GHG emissions and generating value through energy production. Second, direct storage of organic MSW and its derivatives, like biochar, in various carbon sinks allows for extended sequestration, offering a comprehensive approach to address the challenges of waste management and climate change mitigation. Moreover, this review advocates for an extended exploration into several subjects including in-depth analysis of waste, research on MSW-derived biochar recalcitrance across different carbon sinks, and understanding the symbiotic connections with GHG-emitting sectors like agriculture and energy. Finally, this review emphasizes the necessity of conducting life-cycle assessment studies to fully discern the benefits and assess the impacts of any future endeavors exploring the role of MSW in carbon sequestration.

Heterostructure g-C3N4/Bi2MoO6 PVDF nanofiber composite membrane for the photodegradation of steroid hormone micropollutants.

Photocatalytic membrane reactors (PMRs) are a promising technology for micropollutant removal. Sunlight utilization and catalyst surface sites limit photodegradation. A poly(vinylidene fluoride) (PVDF) nanofiber composite membrane (NCM) with immobilized visible-light-responsive g-C3N4/Bi2MoO6 (BMCN) were developed. Photodegradation of steroid hormones with the PVDF-BMCN NCM was investigated with varying catalyst properties, operating conditions, and relevant solution chemistry under solar irradiation. Increasing CN ratio (0-65 %) enhanced estradiol (E2) degradation from 20 ± 10 to 75 ± 7 % due to improved sunlight utilization and photon lifetime. PVDF nanofibers reduced self-aggregation of catalysts. Hydraulic residence time and light intensity enhanced the photodegradation. With the increasing pH value, the E2 removal decreased from 84 ± 4 to 67 ± 7 % owing to electrical repulsion and thus reduced adsorption between catalysts and E2. A removal of 96 % can be attained at environmentally relevant feed concentration (100 ng.L-1) with a flux of 60 L.m-2.h-1, irradiance of 100 mW.cm-2, and 1 mg.cm-2 BMCN65 loading. This confirmed that heterojunction photocatalysts can enhance micropollutants degradation in PMRs.

MXene nanosheet-derived N, S-codoped graphene quantum dots for ultrasensitive and selective detection of 3-nitro-l-tyrosine in human serum.

3-Nitro-l-tyrosine (3NT) is an oxidative stress metabolite associated with neurodegenerative diseases such as Parkinson's disease and rheumatoid arthritis. In this study, the N, S-co-doped graphene quantum dots (NSGQDs) derived from nitrogen-doped Ti3C2Tx MXene nanosheet via the hydrothermal method in the presence of mercaptosuccinic acid was synthesized as an optical sensing probe to detect 3NT in human serum. Tetramethyl ammonium hydroxide, the nitrogen source and delamination agent, was used to prepare nitrogen-doped MXene nanosheets via one step at room temperature. The as-prepared NSGQDs are uniform with an average size of 1.2 ± 0.6 nm, and can be stable in aqueous solution for at least 90 d to serve as the fluorescence probe. The N atoms in N-MXene reduce the restacking and aggregation of MXene nanosheets, while the sulfur dopant in NSGQDs increases the quantum yield from 6.2 to 12.1 % as well as enhances the selectivity of 3NT over the other 12 interferences via coordination interaction with nitro group in 3NT. A linear range of 0.02-150 µM in PBS and 0.05-200 µM in human serum with a recovery of 97-108 % for 3NT detection is observed. Moreover, the limit of detection can be lowered to 4.2 and 7 nM in PBS and 1 × diluted human serum, respectively. Results obtained clearly indicate the potential application of the N-Ti3C2Tx derived NSGQD for effective detection of 3NT, which can open a window for the synthesis of doped GQDs via 2D MXene materials for ultrasensitive and selective detection of other biometabolites and biomarkers of neurodegenerative diseases in biological fluids.

Synergistic Role of the AuAg-Fe3O4 Nanoenzyme for Ultrasensitive Immunoassay of Dengue Virus.

A combination of magnetic and noble metal nanoparticles (NPs) has recently emerged as a potential substance for rapid and sensitive immunosorbent assays. However, to make the assay an alternative method for Enzyme-linked immunosorbent assay, the individual role of each nanoparticle must be explored properly. In this work, an immunoassay has been proposed using two antibody-conjugated iron oxide nanoparticles (Fe3O4NPs) and gold-silver bimetallic nanoparticles (AuAgNPs) to enhance the sensitivity of virus detection by colorimetric TMB/H2O2 signal amplification. A synergistic effect is monitored between Fe3O4NPs and AuAgNPs, which is explored for colorimetric virus detection. The sensor exploits the synergistic effect between the nanoparticles to successfully detect a wide range of dengue virus-like particle (DENV-LP) concentrations ranging from 10 to 100 pg/mL with a detection limit of up to 2.6 fg/mL. In the presence of a target DENV-LP, a sandwich-like structure is formed, which restricts the electron transfer and the associated synergistic effect between the nanoparticles, restricting the TMB oxidation process. Therefore, the synergistic effect is the key to the present work, which accounts for the enhanced rate of the enzymatic reaction on TMB and makes the current method of virus detection more sensitive and reliable compared to the others.

Ni-Co bimetallic decorated dodecahedral ZIF as an efficient catalyst for photoelectrochemical degradation of sulfamethoxazole coupled with hydrogen production.

In this work, a NiCo bimetallic ZIF (BMZIF) dodecahedron material has been synthesized by the precipitation approach and then used for simultaneously photoelectrocatalytic degradation of sulfamethoxazole (SMX) and hydrogen production. The combination of Ni/Co loading in ZIF structure increased the specific surface area 1484 (m2 g-1) and photocurrent density (0.4 mA cm-2), which can facilitate the good charge transfer efficiency. In presence of peroxymonosulfate (PMS, 0.1 mM), the complete degradation of SMX (10 mg L-1) was achieved at initial pH of 7 within 24 min, with the pseudo-first-order rate constants of 0.18 min-1 and TOC removal efficiency of 85 %. Radical scavenger experiments affirm that •OH radicals were the primary oxygen reactive species to drive the SMX degradation. Along with SMX degradation at the anode, the H2 production was observed at the cathode (140 µmol cm-2 h-1), which was 1.5 and 3 times higher than that of Co-ZIF and Ni-ZIF, respectively. The superior catalytic performance of BMZIF was assigned to the distinctive internal structure and synergistic effect between ZIF and Ni/Co bimetals, which improves light absorption and charge conduction efficiency. This study may provide insight into the new way to treat polluted water and simultaneously produce green energy using bimetallic ZIF in a PEC system.

Agricultural waste to real worth biochar as a sustainable material for supercapacitor.

Biochar made from agricultural waste is gaining more attention in energy field due to its sustainability, low cost, apart from having high supercapacitance performance. Also, it has a wide range of environmental applications, including wastewater treatment, upgrading soil fertility, contaminant immobilization, and in situ carbon sequestration. The existing thermo-chemical methodologies for converting agricultural waste into a sustainable material i.e. biochar and the role of activation agents in enhancing the performance of these materials were critically analyzed and discussed. An overview of recent trends in agricultural waste-derived biochar for supercapacitor electrodes is highlighted in this review that emphasizes green circular economy for encouraging net-zero utility of agriculture waste biomass. The roles of various newly prepared "green" electrolytes in reducing the negative consequences of supercapacitor is also reviewed. The trashing of agricultural waste and the depletion of energy supplies has become a global concern, hurting the world's ecosystem and economy through pollution and a fuel crisis and hence the concept of a green circular economic model is also highlighted.

Enhanced Visible-Light-Responsive Photocatalytic Degradation of Ciprofloxacin by the CuxO/Metal-Organic Framework Hybrid Nanocomposite.

Ciprofloxacin (CIP) is a commonly used antibiotic, however, once in the environment, it is highly toxic with a poor biodegradability. Given these attributes, an effective strategy for the removal of CIP is urgently needed for the protection of water resources. Herein, a novel copper metal-organic framework (CuxO/MOF) multifunctional material has been produced, in this work, by the calcination of Cu-MOF urea at 300 °C, in the presence of a 5% H2 atmosphere. The morphological, structural, and thermal properties of the prepared CuxO/MOF were determined through various techniques, and its photocatalytic behavior was investigated for the degradation of CIP under visible-light irradiation. The prepared CuxO/MOF bifunctional material is presented as a graphitic carbon-layered structure with a particle size of 9.2 ± 2.1 nm. The existence of CuO-Cu2O-C, which was found on the CuxO/MOF surface, enhanced the adsorption efficiency and increased the photosensitivity of CuxO/MOF, towards the degradation of CIP in aqueous solutions. The tailored CuxO/MOF, not only shows an excellent CIP degradation efficiency of up to 92% with a constant kinetic rate (kobs) of 0.048 min−1 under visible light, but it can also retain the stable photodegradation efficiency of >85%, for at least six cycles. In addition, CuxO/MOF has an excellent adsorption capacity at pH 6.0 of the maximum Langmuir adsorption capacity of 34.5 mg g−1 for CIP. The results obtained in this study demonstrate that CuxO/MOF is a reliable integrated material and serves as an adsorbent and photocatalyst, which can open a new pathway for the preparation of visible-light-responsive photocatalysts, for the removal of antibiotics and other emerging pollutants.

Hydrothermally synthesized titanium/hydroxyapatite as photoactive and antibacterial biomaterial.

The present work investigated hydrothermal synthesis of titanium/hydroxyapatite (Ti/HA) nanocomposite at varied Ti content. The synthesis was performed by coprecipitation method using CaO, ammonium dihydrogen phosphate and titanium oxide chloride precursor with the additional cetyl trimethyl ammonium chloride as templating agent, followed by hydrothermal treatment at 150 °C. The derived materials were characterized by x-ray diffraction, x-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy analyses. The photocatalytic properties of materials were tested on methyl violet (MV) photocatalytic oxidation, meanwhile the antibacterial testing was performed against Escherichia coli, Staphylococcus aureus, Klebsiella pneumonia, and Streptococcus pyogenes. In addition, cytotoxicity evaluation of the materials as potential biomaterial was also conducted. The results showed that physicochemical character of Ti/HA exhibits exhibit the excellent properties to be photocatalyst along with antibacterial activity. From the detail study of effect of varied titanium content ranging from 5 to 10 %wt., the increasing crystallite size of anatase phase of about 25.81 nm and 38.22 nm for Ti content of 5 and 10 % wt., respectively. In other side, the band gap energy value increases as the increasing Ti content, i.e. the values are 3.08; 3.18; and 3.20 eV for Ti content of 5, 10, 20 % wt., respectively. The band gap energy is correlated with the photocatalytic activity which the highest MV degradation was 96.46% over Ti/HA with 20% wt. of Ti (Ti20/HA). The nanocomposites also express the antibacterial activity with comparable minimum inhibitory concentration (MIC) with other similar Ti/HA nanocomposites. The MIC values of Ti20/HA against E. coli, S. aureus, K. pneumonia, and S. pyogenes are 25; 25; 50 and 50 µg/mL, respectively. In addition, the cytotoxicity test revealed the potency to be a biomimetic material as shown by severe toxicity.

Nanomedicines Targeting Glioma Stem Cells.

Glioblastoma (GBM), classified as a grade IV glioma, is a rapidly growing, aggressive, and most commonly occurring tumor of the central nervous system. Despite the therapeutic advances, it carries an ominous prognosis, with a median survival of 14.6 months after diagnosis. Accumulating evidence suggests that cancer stem cells in GBM, termed glioma stem cells (GSCs), play a crucial role in tumor propagation, treatment resistance, and tumor recurrence. GSCs, possessing the capacity for self-renewal and multilineage differentiation, are responsible for tumor growth and heterogeneity, leading to primary obstacles to current cancer therapy. In this respect, increasing efforts have been devoted to the development of anti-GSC strategies based on targeting GSC surface markers, blockage of essential signaling pathways of GSCs, and manipulating the tumor microenvironment (GSC niches). In this review, we will discuss the research knowledge regarding GSC-based therapy and the underlying mechanisms for the treatment of GBM. Given the rapid progression in nanotechnology, innovative nanomedicines developed for GSC targeting will also be highlighted from the perspective of rationale, advantages, and limitations. The goal of this review is to provide broader understanding and key considerations toward the future direction of GSC-based nanotheranostics to fight against GBM.

The Effect of G. applanatum Crude Polysaccharide Extract on Proinflammatory Cytokines and Proapoptotic Caspases in HeLa Cell Line: An In Vitro Study.

Polysaccharide extracts exhibit promise as potential anticancer agents. Among the fungi rich in polysaccharide content, G. applanatum stands out; however, its anticancer activity necessitates further investigation. This study aims to explore the impact of G. applanatum crude polysaccharide (GACP) extract by assessing its effects on cell viability, levels of proinflammatory cytokines such as TNF-α, IFN-γ, IL-2, and IL-12, and levels of proapoptotic markers including caspase-3 and caspase-9, as well as the percentages of necrosis and apoptosis in the HeLa cell line. Employing the HeLa cell line as a research model, four groups were studied: KN (media and DMSO), K+ (doxorubicin 10 µg/mL), P1 (G. applanatum extract 200 µg/mL), and P2 (G. applanatum extract 400 µg/mL). The G. applanatum extract was obtained via boiling distilled water. Anticancer activity was evaluated through the MTT test (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide) conducted over three treatment durations (24, 48, and 72 hours). Cytokine levels and caspase-3 and caspase-9 levels were assessed using the ELISA test. Cell apoptosis was determined using the Annexin V-PI biomarker and analyzed through flow cytometry. The MTT test exhibited optimal results at the 48-hour treatment mark. Cytokine level analysis revealed significant reductions in TNF-α, IFN-γ, IL-2, and IL-12 levels (p < 0.005). Concurrently, caspase-3 and caspase-9 levels exhibited substantial increases (p < 0.005). Flow cytometry highlighted the highest percentage of apoptosis in HeLa cells. In conclusion, G. applanatum's polysaccharide extract demonstrates potential as an anticancer and therapeutic agent for cancer treatment.

Engineered synthetic polymer nanoparticles as IgG affinity ligands.

A process for the preparation of an abiotic protein affinity ligand is described. The affinity ligand, a synthetic polymer hydrogel nanoparticle (NP), is formulated with functional groups complementary to the surface presentation of the target protein. An iterative process is used to improve affinity by optimizing the composition and proportion of functional monomers. Since the polymer NPs are formed by a kinetically driven process, the sequence of functional monomers in the polymer chain is not controlled; only the average composition can be adjusted by the stoichiometry of the monomers in the feed. To compensate for this the hydrogel NP is lightly cross-linked resulting in chain flexibility that takes place on a submillisecond time scale allowing the polymer to "map" onto a protein surface with complementary functionality. In this study, we report a lightly cross-linked (2%) N-isopropyl acrylamide (NIPAm) synthetic polymer NP (50-65 nm) incorporating hydrophobic and carboxylate groups that binds with high affinity to the Fc fragment of IgG. The affinity and amount of NP bound to IgG is pH dependent. The hydrogel NP inhibits protein A binding to the Fc domain at pH 5.5, but not at pH 7.3. A computational analysis was used to identify potential NP-protein interaction sites. Candidates include a NP binding domain that overlaps with the protein A-Fc binding domain at pH 5.5. The computational analysis supports the inhibition experimental results and is attributed to the difference in the charged state of histidine residues. Affinity of the NP (3.5-8.5 nM) to the Fc domain at pH 5.5 is comparable to protein A at pH 7. These results establish that engineered synthetic polymer NPs can be formulated with an intrinsic affinity to a specific domain of a large biomacromolecule.

Clay-Supported Metal Oxide Nanoparticles in Catalytic Advanced Oxidation Processes: A Review.

Advanced oxidation processes (AOPs) utilizing heterogeneous catalysts have attracted great attention in the last decade. The use of solid catalysts, including metal and metal oxide nanoparticle support materials, exhibited better performance compared with the use of homogeneous catalysts, which is mainly related to their stability in hostile environments and recyclability and reusability. Various solid supports have been reported to enhance the performance of metal and metal oxide catalysts for AOPs; undoubtedly, the utilization of clay as a support is the priority under consideration and has received intensive interest. This review provides up-to-date progress on the synthesis, features, and future perspectives of clay-supported metal and metal oxide for AOPs. The methods and characteristics of metal and metal oxide incorporated into the clay structure are strongly influenced by various factors in the synthesis, including the kind of clay mineral. In addition, the benefits of nanomaterials from a green chemistry perspective are key aspects for their further considerations in various applications. Special emphasis is given to the basic schemes for clay modifications and role of clay supports for the enhanced mechanism of AOPs. The scaling-up issue is suggested for being studied to further applications at industrial scale.

Erbium-Doped GQD-Embedded Coffee-Ground-Derived Porous Biochar for Highly Efficient Asymmetric Supercapacitor.

A nanocomposite with erbium-doped graphene quantum dots embedded in highly porous coffee-ground-derived biochar (Er-GQD/HPB) was synthesized as a promising electrode material for a highly efficient supercapacitor. The HPB showed high porosity, with a large surface area of 1295 m2 g-1 and an average pore size of 2.8 nm. The 2-8-nanometer Er-GQD nanoparticles were uniformly decorated on the HPB, subsequently increasing its specific surface area and thermal stability. Furthermore, the intimate contact between the Er-GQDs and HPB significantly reduced the charge-transfer resistance and diffusion path, leading to the rapid migration of ions/electrons in the mesoporous channels of the HPB. By adding Er-GQDs, the specific capacitance was dramatically increased from 337 F g-1 for the pure HPB to 699 F g-1 for the Er-GQD/HPB at 1 A g-1. The Ragone plot of the Er-GQD/HPB exhibited an ultrahigh energy density of 94.5 Wh kg-1 and a power density of 1.3 kW kg-1 at 1 A g-1. Furthermore, the Er-GQD/HPB electrode displayed excellent cycling stability, and 81% of the initial capacitance remained after 5000 cycles. Our results provide further insights into a promising supercapacitance material that offers the benefits of both fast ion transport from highly porous carbons and electrocatalytic improvement due to the embedment of Er-doped GQDs to enhance energy density relative to conventional materials.

Recent Advances in Nanomaterial-based Optical Biosensors as Potential Point-of-Care Testing (PoCT) Probes in Carcinoembryonic Antigen Detection.

For the past decades, several cancer biomarkers have been exploited for rapid and accurate prognosis or diagnosis purposes. In this review, the optical biosensor is targeted for carcinoembryonic antigen (CEA) detection. The CEA level is a prominent parameter currently used in clinical cases for the prognosis of cancer-related diseases. Many nanomaterial-based biosensors are invented as alternatives for the commonly used enzyme-linked immunosorbent assays (ELISA) immunoassay method in CEA detection as the traditional approach. But they possess certain drawbacks such as tedious procedure, high technical demand, and costly. Nevertheless, the effort appears to be wasted as none of them are being actualised. Generally, the sensor function was carried out by converting bio-signals generated upon the interface of the receptor into light signals. These sensors were popular due to specific advantages such as sensitivity, being free from chemical and electromagnetic interferences, wide dynamic range, and being easy to be monitored. The features of PoC diagnostics are discussed and associated to the various applications of colorimetric-based and chemiluminescent-based biosensors. The roles of nanomaterials in each application were also summarised by comparing the modification, incubation period, lowest detection limit (LOD) and linear range of detection amount. The challenges and future perspectives were highlighted as well at the end of the review.