Doxorubicin encapsulated blend of sitagliptin-lignin polymeric drug delivery system for effective combination therapy against cancer.

In this research, a sitagliptin-lignin biopolymer (SL) containing zinc selenide quantum dots (ZnSe QDs) and doxorubicin (doxo) was synthesized. The fabricated polymeric drug delivery system was characterized via FTIR, XRD, SEM, TGA, IR, and DSC. SLQD-Doxo exhibited an irregular surface with a 32 nm diameter and well-defined surface chemistry. Drug loading efficiency was assessed at different concentrations, pH levels, time intervals, and temperatures, and drug kinetics were calculated. Maximum drug release was observed at 6 µmol concentration after 24 h, pH of 6.5 and 45 °C. The maximum drug encapsulation efficiency was 81.75 %. SLQD-Doxo demonstrated 24.4 ± 1.04 % anti-inflammatory activity, and the maximum lipoxygenase inhibition in a concentration-dependent manner was 71.45 ± 2.02 %, compared to indomethacin, a standard anticancer drug. The designed system was applied to breast cancer MCF-7 cells to evaluate anticancer activity. Cytotoxicity of SLQD-Doxo resulted in 24.48 ± 1.64 dead cells and 74.39 ± 4.12 viable cells. Lignin's polyphenolic nature resulted in good antioxidant activity of LLQD-Doxo. The combination of SLQD-Doxo was appropriate for drug delivery at high temperatures and acidic pH of tumor cells compared to healthy cells.

Effect of salinity on growth and biochemical responses of brinjal varieties: implications for salt tolerance and antioxidant mechanisms.

Salinity poses significant challenges to agricultural productivity, impacting crops' growth, morphology and biochemical parameters. A pot experiment of three months was conducted between February to April 2023 in the Department of Botany, The Islamia University of Bahawalpur. Four brinjal (eggplant) varieties: ICS-BR-1351, HBR-313-D, HBR-314-E, and HBR-334-D were selected and assessed for the effects of salinity on various growth and biochemical attributes. The experiment was completely randomized in design with three replicates each. This study revealed that increased salinity significantly reduced the shoot length, root length, and leaf number across all varieties, with maximum adverse effects observed at a 300mM NaCl concentration. Among the tested varieties, ICS-BR-1351 demonstrated superior performance in most growth parameters, suggesting potential salt tolerance. Biochemically, salinity decreased chlorophyll content across all varieties, with the sharpest decline observed at the highest salt concentration. V4 (HBR-334-D) showed a 57% decrease in chlorophyll followed by V3 (HBR-314-E) at 56%, V2 (HBR-313-D) at 54%, and V1 (ICS-BR-1351) at 33% decrease at maximum salt levels as compared to control. Conversely, carotenoid content increased up to -42.11% in V3 followed by V2 at -81.48%, V4 at -94.11%, and - 233% in V1 at 300mM NaCl stress as compared to respective controls. V3 (HBR-314-E) has the maximum value for carotenoids while V1 has the lowest value for carotenoids as compared to the other three brinjal varieties. In addition to pigments, the study indicated a salinity-induced decrease in total proteins and total soluble sugar, whereas total amino acids and flavonoids increased. Total proteins showed a decrease in V2 (49.46%) followed by V3 (36.44%), V4 (53.42%), and V1 (53.79%) at maximum salt concentration as compared to plants treated with tap water only. Whereas, total soluble sugars showed a decrease of 52.07% in V3, 41.53% in V2, 19.49% in V1, and 18.99% in V4 at the highest salt level. While discussing total amino acid, plants showed a -9.64% increase in V1 as compared to V4 (-31.10%), V2 (-36.62%), and V3 (-22.61%) with high salt levels in comparison with controls. Plant flavonoid content increased in V3 (-15.61%), V2 (-19.03%), V4 (-18.27%) and V1 (-27.85%) at 300mM salt concentration. Notably, salinity elevated the content of anthocyanin, lycopene, malondialdehyde (MDA), and hydrogen peroxide (H2O2) across all varieties. Antioxidant enzymes like peroxidase, catalase, and superoxide dismutase also increased under salt stress, suggesting an adaptive response to combat oxidative damage. However, V3 (HBR-314-E) has shown an increase in anthocyanin at -80.00%, lycopene at -24.81%, MDA at -168.04%, hydrogen peroxide at -24.22%, POD at -10.71%, CAT as-36.63 and SOD as -99.14% at 300mM NaCl stress as compared to control and other varieties. The enhanced accumulation of antioxidants and other protective compounds suggests an adaptive mechanism in brinjal to combat salt-induced oxidative stress. The salt tolerance of different brinjal varieties was assessed by principal component analysis (PCA), and the order of salt tolerance was V1 (ICS-BR-1351) > V4 (HBR-334-D), > V2 (HBR-313-D) > V3 (HBR-314-E). Among the varieties studied, ICS-BR-1351 demonstrated resilience against saline conditions, potentially offering a promising candidate for saline-prone agricultural areas.

Improved Electrochemical Performance of Aqueous Hybrid Supercapacitors Using CrCo2O4 Mesoporous Nanowires: An Innovative Strategy toward Sustainable Energy Devices.

High-rate aqueous hybrid supercapacitors (AHSCs) have attracted relevant scientific significance owing to their expected energy density, supercapacitor-level power density, and battery-level energy density. In this work, a bimetallic nanostructured material with chromium-incorporated cobalt oxide (CCO, i.e., CoCr2O4) was prepared via a hydrothermal method to form a stable cubic obelisk structure. Compared with CCO materials prepared using traditional methods, CCO displayed a nanowire structure (50 nm diameter), suggesting an enhanced specific surface area and a large number of active sites for chemical reactions. The electrode possessed a high specific capacitance (2951 F g-1) at a current density of 1 A g-1, minimum Rct (0.135 Ω), and the highest capacitance retention (98.7%), making it an ideal electrode material for AHSCs. Ex situ analysis based on X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) showed a favorable stability of CCO after 10,000 cycles without any phase changes being detected. GGA and GGA + U methods employed in density functional theory (DFT) also highlighted the enhanced metallic properties of CCO originating from the synergistic effect of semiconducting Cr2O3 and Co3O4 materials.

Synthesis of novel nonsteroidal anti-inflammatory galloyl ß-sitosterol-loaded lignin-capped Ag-based drug.

Biocompatible anti-inflammatory lignin-capped Ag (LCAg) nanoparticles (NPs) were synthesized for the delivery of galloyl ß-sitosterol (Galloyl-BS). ß-Sitosterol (BS) is effective against inflammatory responses, like cancer-induced inflammations. BS was modified via gallic acid esterification to enhance its anti-inflammatory potential. LCAg NPs were synthesized by a green method and loaded with galloyl-BS. For comparison, pure BS was also loaded onto LCAg NPs in a separate assembly. The antioxidant potential of Galloyl-BS was greater (IC50 177 µM) than pure BS. Materials were characterized by FT-IR, SEM, XRD, and Zeta potential. Using UV-Vis spectroscopy, drug release experiments were performed by varying pH, time, concentration, and temperature. Maximum drug release was observed after 18 h at pH 6 and 40 °C. Galloyl-BS showed improved drug loading efficiency, release %age, and antioxidant activity compared to pure BS when loaded onto LCAg NPs. DLCAg exhibited excellent anti-inflammatory activity in rat models. These findings indicate that galloyl-BS (drug)-loaded LCAg (DLCAg) NPs have the potential as an anti-inflammatory agent without any prior release and scavenging in normal cells.

Graphitic carbon nitride derived probes for the recognition of heavy metal pollutants of environmental concern in water bodies.

Graphitic carbon nitride (g-CN) has a number of valuable features that have been recognized during the studies related to its photocatalytic activity enhancement derived by visible light. Because of these characteristics, g-CN can be used as a detecting signal transducer with different transmission modalities. The latest up-to-date detection capabilities of modified g-CN nanoarchitectures are covered in this study. The structural features and synthetic methodologies have been discussed in a number of reports. Herein, employment of the g-CN as a promising probing modality for the recognition of different toxic heavy metals is the promising feature of the present study.

Silica quantum dots; an optical nanosensing approach for trace detection of pesticides in environmental and biological samples.

Both the environment and human health have suffered as a result of excessive and irrational pesticide use. The human body is vulnerable to a wide range of illnesses brought on by prolonged exposure to or intake of food contaminated with pesticide residues, including immunological and hormonal abnormalities and the development of certain tumors. Sensors based on nanoparticles stand out from more conventional spectrophotometry analytical methods due to their low detection limits, high sensitivity, and ease of use; that is why the demand for simple, fast, and less expensive sensing methods increases daily and presents myriad uses. Such demands are fulfilled by employing paper-based analytical devices having intrinsic properties. The presented work reports an on-site, easy-to-handle, and disposable paper-based sensing device for performing fast screening along with readout from a smartphone. The fabricated device utilizes luminescent silica quantum dots, immobilized into a paper cellulose matrix, and the resonance energy transfer phenomenon is employed. The silica quantum dots probes were fabricated from citric acid and, by undergoing physical adsorption, were confined on the nitrocellulose substrate in small wax-traced spots. The silica quantum dots were excited by smartphone ultraviolet LED, acting as an energy source and for capturing the image. The obtained LOD is 0.054 µM, and the coefficient of variation is less than 6.1%, comparable to the result obtained by UV-Visible and fluorometric analysis under similar experimental conditions. In addition, high reproducibility (≥9.8%) and high recovery ≥90% were obtained in spiked blood samples. The fabricated sensor sensitively detected pesticides giving a LOD of 2.5 ppm along with the development of yellow color within a short period of 5 min. The sensor functions well when sophisticated instrumentation is not accessible. The presented work shows the potential of the paper strip for the on-site detection of pesticides in biological and environmental samples.

Facile synthesis of Ag@Fe3O4/ZnO nanomaterial for label-free electrochemical detection of methemoglobin in anemic patients.

Methemoglobinemia (MetHb, Fe3+) is a chronic disease arising from the unequal distribution of oxyhemoglobin (HbFe2+, OHb) in the blood circulatory system. The oxidation of standard oxyhemoglobin forms methemoglobin, causing cyanosis (skin bluish staining). Methemoglobin cannot bind the pulmonary gaseous ligands such as oxygen (O2) and carbon monoxide (CO). As an oxidizing agent, the biochemical approach (MetHb, Fe3+) is modified in vitro by sodium nitrite (NaNO2). The silver-doped iron zinc oxide (Ag@Fe3O4/ZnO) is hydrothermally synthesized and characterized by analytical and spectroscopic techniques for the electrochemical sensing of methemoglobin via cyclic voltammetry (CV). Detection parameters such as concentration, pH, scan rate, electrochemical active surface area (ECSA), and electrochemical impedance spectroscopy (EIS) are optimized. The linear limit of detection for Ag@Fe3O4/ZnO is 0.17 µM. The stability is determined by 100 cycles of CV and chronoamperometry for 40 h. The serum samples of anemia patients with different hemoglobin levels (Hb) are analyzed using Ag@Fe3O4/ZnO modified biosensor. The sensor's stability, selectivity, and response suggest its use in methemoglobinemia monitoring.

Hydrothermally synthesized Ag-TiO2 nanofibers (NFs) for photocatalytic dye degradation and antibacterial activity.

This work successfully utilised eco-friendly green synthesis to produce Ag-TiO2 nanofibers (NFs). As pollution and energy limitations have become global issues, there is an ongoing need to develop more effective catalysts through straightforward and environmentally friendly methods. The Ag-TiO2 nanofibers (NFs) XRD pattern exhibits an anatase TiO2 and FCC crystal structure of Ag nanoparticles. The SEM investigation revealed a nanofiber-like surface morphology. The Ag-TiO2 nanofibers (NFs) exhibits an optical band gap energy is 2.5 eV. Methylene blue (MB), malachite green (MG), Congo red (CR), and crystal violet (CV) dye aqueous solutions were used to evaluate the photocatalytic performance of the synthesized Ag-modified TiO2 nanofibers (NFs) under direct sunlight irradiation. The effects of catalyst size on the efficient breakdown of MB dye were also investigated. The optimum catalyst concentration was found to be at 0.02 mg/mL. At 120 min of direct sunlight, the highest photosynthetic degradation efficiency (DE percentage) of 94% was achieved for MB dye. Ag-TiO2 nanofibers (NFs) have been demonstrated to have exceptional antibacterial activity against Gram-positive bacteria such as Staphylococcus aureus and Gram-negative bacteria E-Coli. Because of these great qualities, it seems likely that the Ag-TiO2 nanofibers (NFs) made could be a great photocatalyst for getting dye pollutants out of wastewater.

Hydrophobic ammonium based ionic liquids for efficient extraction of textile dyes from aqueous media: Extraction study and antibacterial evaluation.

Alizarin red S (ARS) extraction from aqueous medium was carried out using hydrophobic ionic liquids (ILs) containing trioctylammonium cation paired with 4-tert-butylbenzoate ([TOA][Butbenz] (IL1), 4-phenylbutanoate ([TOA][PheBut] (IL2), 3-4-dimethylbenzoate ([TOA][DMbenz] (IL3), naphthoate, ([TOA][Naph]) (IL4), salicylate ([TOA][Sali]) (IL5) and nonanedioate ([TOA]2[Nona]) (IL6). The findings demonstrated that all of the tested ILs were efficient for extracting ARS, however, [TOA]2[Nona] was more effective than others. For the extraction of ARS from the aqueous phase, the effects of various parameters including the initial pH of the dye solution, contact time, ILs to dye volume ratio (VIL:VW), dye concentration, temperature, and salt effect were investigated. The spontaneity of the liquid-liquid extraction of ARS from the aqueous phase to the IL phase was confirmed by thermodynamic parameters. More than 90% of the ARS was extracted from the aqueous phase to the IL phase throughout all experiments. Interaction of selected IL with dyes were confirmed using FTIR analysis. The standard bacterial strains of Escherichia coli (E. coli) ATCC BAA-2471 (gram negative) and Methicillin-resistant Staphylococcus (MRSA) ATCC 43300 (gram positive) were used for evaluating antibacterial activity. The lower dose (250 ppm), the ILs1, 2, 3, 4, 5, and 6 inhibited 0.40, 1.50, 6.50, 1.50, 2.50, and 0.50 mm growth of E. coli, and 4.0, 2.0, 16.50, 0.40, 5.0, and 3.50 mm growth of MRSA, respectively. The experimental findings confirmed that the present ILs can be utilized as an effective solvent for ARS and other dyes extraction from aqueous media.

Cost-effective fabrication, antibacterial application and cell viability studies of modified nonwoven cotton fabric.

In the present work, nonwoven cotton fabric was modified for antibacterial applications using low-cost and eco-friendly precursors. The treatment of fabric with alkali leads to the formation of active sites for surface modification, followed by dip coating with silver nanoparticles and chitosan. The surface was chlorinated in the next step to transform amide (N-H) groups in chitosan into N-halamine (N-Cl). The modified and unmodified surfaces of the nonwoven cotton fabric have been characterized by FTIR, SEM, and XRD. The active chlorine loading is measured with iodine/sodium thiosulphate. The antimicrobial activity and cell toxicity assay were carried out with and without modifications of nonwoven cotton fabric. The antimicrobial efficacies of loaded fabric were evaluated against four bacterial species (Micrococcus luteus, Staphylococcus aureus, Enterobacter aerogenes, and E.coli). It was found that modified fabric exhibited superior efficiency against gram-positive and gram-negative bacterial strains as compared to their bulk counterparts upon exposure without affecting strength and integrity of fabric. The overall process is economical for commercial purposes. The modified fabric can be used for antimicrobial, health, and food packaging industries, and in other biomedical applications.

Octylamine as environment friendlier colorimetric detection probe for hazardous 2,4,6-Trinitrophenol from wastewater samples.

The precise detection of hazardous 2,4,6-Trinitrophenol (TNP) is essential for the environment and human health. TNP is used as a precursor in whistling fireworks in ammunition, mining, agriculture and is a hazardous environmental pollutant generated from leather, chemical, and dye industries. Exploring rapid and low-cost approaches for the detection and quantification of TNP has attracted many scientists nowadays. The proposed chemosensor utilizes the concept of dispersive liquid-liquid micro-extraction coupled with a UV-visible spectrophotometer for its sensing at the ultra-trace level. Significant changes based on intramolecular interactions followed by a distinct color change to orange-red from yellow in the presence of TNP is an attractive feature for the present study. The successive addition of TNP shows ultra-trace sensitivity (3.9831 µA µM-1 cm-1) at detection limit (LOD) of 0.0015 ± 0.03 µM (S/N = 3), a linear range of 0 µM-70 µM, and a response time of <5 min. Different types of real samples such as creatinine testing kit reagent, fireflies crackers, serum, and water samples were used and recovery of TNP was calculated by spiking the known concentration of the standard analyte. The obtained recovery was 93.6-103.6% with RSD range of 1.6-4.53% (n = 3) in different samples. The analytical performance of the colorimetric Chemoprobe in terms of its recovery, linearity range, and limit of detection offers an excellent platform for monitoring hazardous TNP. The results show that the proposed colorimetric chemosensor is easy to use, low-cost, environmentally friendly and offers an easily observable visual color change. Based on these features, the chemosensor can be used for large-scale applications for the detection of TNP in water and other samples.

Facile hydrothermal synthesis of NiTe nanorods for non-enzymatic electrochemical sensing of whole blood hemoglobin in pregnant anemic women.

Electrochemical sensing methods monitor biomolecules because of their specificity, rapid response, lower cost, and automation. Hemoglobin is an abundant protein in the human body and is correlated with various physiological processes. Levels of hemoglobin in blood are associated with anemia in pregnant women. In this research, a non-enzymatic sensor based on NiTe nanorods is developed for the detection and quantification of hemoglobin (Hb) from anemic pregnant patients. NiTe nanorods are synthesized by the single-step method. After characterizing the material, sensing parameters such as the effect of scan rate, pH, concentration, and interferences are optimized using standard hemoglobin samples. Linearity, the limit of detection (LOD), and the limit of quantification (LOQ) for NiTe nanorods are 0.99698, 0.012 nM, and 0.04 nM, respectively. Stability is measured by cyclic chronoamperometry (12 h) and voltammetry (100 cycles). Recovery of hemoglobin from blood samples is in the range of 63-90%. NiTe nanorods quantitatively determine hemoglobin from the blood samples of anemic pregnant women.

Tin derived antimony/nitrogen-doped porous carbon (Sb/NPC) composite for electrochemical sensing of albumin from hepatocellular carcinoma patients.

An electrochemical sensor based on an antimony/nitrogen-doped porous carbon (Sb/NPC) composite has been developed for the quantitative detection of albumin from hepatocellular carcinoma (HCC) patients. Sb/NPC is hydrothermally synthesized from Sn/NPC precursors. The synthesized precursor (Sn/NPC) and the product (Sb/NPC) are characterized by XRD, FTIR, TGA, UV/Vis, SEM, and AFM. Cyclic voltammetry, chronoamperometry, and electrochemical impedance studies are used to investigate the electrochemical performance of Sb/NPC-GCE. Sb/NPC-GCE detects albumin at physiological pH of 7.4 in the potential range 0.92 V and 0.09 V for oxidation and reduction, respectively. LOD and recovery of Sb/NPC-GCE for the determination of albumin are 0.13 ng.mL-1 and 66.6 ± 0.97-100 ± 2.73%, respectively. Chronoamperometry of the modified working electrode demonstrates its stability for 14 h, indicating its reusability and reproducibility. Sb/NPC-GCE is a selective sensor for albumin detection in the presence of interfering species. The electrode has been applied for albumin detection in human serum samples of HCC patients. A negative correlation of albumin with alpha-fetoprotein levels in HCC patients is observed by statistical analysis.

Quantitative determination of creatinine from serum of prostate cancer patients by N-doped porous carbon antimony (Sb/NPC) nanoparticles.

Creatinine is an indicator of hindrance in urination and renal insufficiency. Creatinine levels are the marker of the late stages of prostate cancer. Early and sensitive detection of creatinine can reduce deaths associated with prostate cancer. In this work, nitrogen-doped porous carbon antimony (Sb/NPC) nanoparticles are fabricated to be employed as a non-enzymatic biosensor. Sb/NPC has promising redox activity and is synthesized by a two-step reaction using low-cost precursors. Electrochemical sensing by Sb/NPC is conducted for standard creatinine solutions on a three-electrodes system. Cyclic voltammetry, amperometry, and electrochemical impedance spectroscopy are used to sense creatinine. LOD and LOQ of the Sb/NPC modified electrode are 0.74 µM and 2.4 µM, respectively. This electrode system analyzes creatinine in the serum of prostate cancer patients who have elevated PSA levels. More than 90% creatinine is recovered from a spiked serum sample of a prostate cancer patient. A direct relation is observed between PSA levels and creatinine levels in prostate cancer. The developed cyclic voltammetric setup detects trace concentrations of creatinine in serum.

Chlorfenapyr containing anions uptake from industrial wastewater by ethylene glycol functionalized benzyl dimethyl tetradecyl ammonium bromide membrane.

The preservation of water and wastewater treatment has become a global challenge. The concentration of anions such as chlorides, fluorides, cyanides, and perchlorates above the permitted levels in water is harmful to human and aquatic life. Chlorfenapyr is an insecticide that contains the aforesaid anions and is abundantly present in industrial wastewater. This research is focused on the removal of these anions from wastewater by ethylene glycol functionalized benzyl dimethyl tetradecyl ammonium bromide immobilized on soluble polymer anion exchange membrane. The real wastewater samples rich in chlorfenapyr from two different sources (industrial and pond) were analyzed. Membrane efficiency was more than 50 ppm for each anion in a single fold. The double folds of membrane showed enhanced uptake and separation efficiency for chloride, fluoride, and cyanide from wastewater samples between 0.01 and 0.02 ppm down to lethal concenetrations values (LD 50). The membrane shows maximum separation efficiency between the pH ranges of 6-7. The interference effect on membrane separation efficiency showed that the replacement ability of sample anions was in the order of fluoride > chloride > perchlorate > cyanide. This high replacement efficiency of fluoride and chloride is attributed to the more chemical interactions of these anions with membrane.

Hydrazone connected stable luminescent covalent-organic polymer for ultrafast detection of nitro-explosives.

Developing promising luminescent probes for the selective sensing of nitro-explosives remains a challenging issue. Porous luminescent covalent-organic polymers are one of the excellent sensing probes for trace hazardous materials. Herein, fluorescent monomers 1,1,2,2-tetrakis(4-formyl-(1,1'-biphenyl))ethane (TFBE) and 1,3,5-benzenetricarboxylic acid trihydrazide (BTCH) were selected to build a novel hydrazone connected stable luminescent covalent-organic polymer (H-COP) of high stability by typical Schiff-base reaction. The N2 sorption study, BET surface area analysis, and TGA profile indicate the porosity and stability of this H-COP material. Such properties of the H-COP material enable a unique sensing platform for nitro-explosives with great sensitivity (Ksv ∼ 106 M) and selectivity up to µM. This polymer material shows attractive selectivity and sensitivity towards phenolic nitro-explosives and other common explosives among earlier reported COP-based sensors.

Tellurium doped zinc imidazole framework (Te@ZIF-8) for quantitative determination of hydrogen peroxide from serum of pancreatic cancer patients.

The tellurium doped zinc imidazole framework (Te@ZIF-8) is prepared by a two-step hydrothermal strategy for the electrochemical sensing of hydrogen peroxide. Material is characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The electrochemical characterization of the MOF modified electrode is done by a three-electrode system. Electrochemical sensing of hydrogen peroxide is made by cyclic voltammetry, amperometry, and impedance measurements. Results demonstrate that Te@ZIF-8 shows a detection limit of 60 µM with linearity up to 0.98855. Material is stable to 1000 cycles with no significant change in electrochemical response. Amperometry depicts the recovery of hydrogen peroxide from human serum up to 101%. Impedance curve reveals the surface of Te@ZIF-8-GCE (glassy carbon electrode) as porous and rough and an interface is developed between analyte ions and the sensing material. Finally, the modified electrode is used for the quantitative determination of hydrogen peroxide from serum samples of pancreatic cancer patients, diagnosed with CA 19-9.

Catalase immobilized antimonene quantum dots used as an electrochemical biosensor for quantitative determination of H2O2 from CA-125 diagnosed ovarian cancer samples.

A selective and cost-effective biosensor based on catalase immobilized antimonene quantum dots modified glassy carbon electrode (Cat@AMQDs-GCE) is designed for the first time to determine hydrogen peroxide (H2O2). Antimonene quantum dots (AMQDs) are synthesized by a single step method, characterized by various analytical techniques and applied to the electrochemical sensing of hydrogen peroxide. Catalase enzyme specific for H2O2 reduction is immobilized onto AMQDs to facilitate its detection by cyclic voltammetry and amperometry. Concentration, scan rate, pH, stability and selectivity are optimized. Linearity of Cat@AMQDs-GCE is determined as 0.989 with limit of detection as 4.4 µM. Amperometric measurements show recovery of 95 to 103.4% for H2O2 from human serum samples. Cat@AMQDs-GCE is electrochemically stable up to 30 cycles, reducing the cost of analysis. Cat@AMQDs-GCE shows good selectivity in presence of ascorbic acid, dopamine, leucine and glucose. Prepared electrode is also applied for the quantitative determination of H2O2 from ovarian cancer serum. CA 125 concentration is previously determined by Elecsys CA 125 II Assay. Results demonstrate that concentration of H2O2 increases with increasing levels of CA125 in serum.

Facile liquid-phase deposition synthesis of titania-coated magnetic sporopollenin for the selective capture of phosphopeptides.

Titania-grafted magnetic sporopollenin is synthesized by the liquid-phase deposition (LPD) technique, characterized by SEM, EDX, and nitrogen adsorption porosimetry, and used for the selective enrichment of phosphorylated peptides. The material is low cost because of easier availability of pollens and has rich surface chemistry which enables strong attachment of titania onto magnetic sporopollenin. The material shows higher selectivity of 1:1000 with ß-casein spiked in BSA. Higher sensitivity of 10 fmol is recorded for phosphopeptides from standard ß-casein digest. Twenty phosphorylated peptides are enriched from milk digest and four endogenous phosphopeptides from diluted human serum. The magnetic property of titania-coated magnetic sporopollenin facilitates the fast and effective isolation of phosphopeptides from complex mixtures through external magnet. The material is finally applied to tryptic digest of rat brain cell lysate for phosphopeptide enrichment where 2718 phosphopeptides are identified by using LC-MS/MS with C18 column. Titania-coated magnetic sporopollenin captures both mono-phosphorylated (2489) and multi-phosphorylated peptides (229) due to strong affinity of TiO2 with phosphates. TiO2-coated magnetic material also shows better enrichment efficiency in comparison to commercial TiO2. Graphical abstract.

Synthesis, design and sensing applications of nanostructured ceria-based materials.

Cerium-based materials possess redox properties due to the presence of dual valence states of Ce3+ and Ce4+. In the last few years, the scientific community has paid much attention to designing and synthesizing cerium-based materials through advantageous routes for widespread catalytic and sensing applications in many fields. Cerium materials have been synthesized in many different forms, shapes and sizes. The catalytic and sensing capabilities of cerium nanostructures are highly dependent on their morphologies and can be improved significantly by modifying the sizes and shapes of the nanostructures to develop sensing scaffolds with improved sensing performance. These nanostructures provide a basis for applications in many fields. From a literature survey (2010 to 2015), it can be concluded that the fundamental morphologies, ratios, and capping of cerium nanostructures (CeNSs) constructively affect their properties and applications. Designed sensors utilizing CeNSs exhibit outstanding stability, high selectivity and eminent reproducibility in relation to time and temperature. This review will provide a perspective insight on the future trends in the design of different morphologies of CeNSs and their promising applications.