Papers by Keyword: Glucose

Abstract: The rising demand for fossil-derived feedstocks for plastics production poses a critical sustainability challenge. 5-Hydroxymethylfurfural (5-HMF) has emerged as a key platform chemical and a promising precursor to 2,5-furandicarboxylic acid (FDCA), which is used in the production of bio-based plastics. This study investigated the effects of acid concentration (1% and 5% w/w H₂SO₄), temperature (120°C, 140°C, and 160°C), and time (10–90 minutes) on the acid hydrolysis of mango seed husk for 5-HMF production. Results show that increasing acid concentration, reaction time, and temperature positively influence 5-HMF yields, with a maximum concentration of 0.00166 mmol/100 mL obtained under 5% acid at 140°C for 50 minutes. Kinetic and thermodynamic data of 5-HMF production and decomposition were also determined, providing insights into optimizing process conditions for efficient conversion of lignocellulosic biomass into this critical precursor for bio-based plastics.

Abstract: The development of non-enzymatic glucose biosensor has been the concern of many researchers mainly because enzymes based sensor despite having excellent sensitivity and selectivity, has the limitations such as poor stability, complicated enzyme immobilization, critical operating conditions such as optimum temperature and reproducibility. This study developed a cheap biocompatible non-enzymatic glucose biosensor based on silver nanoparticle (AgNPs) stabilized with sodium tripolyphosphate (NaTPP) cross-linked chitosan. Direct electron transfer and electro-catalytic activity of the AgNPs modified glassy carbon electrode (AgNPGCE) was investigated using potentiometric and amperometric techniques. AgNPs was prepared and characterized by Fourier transform Infra-red spectroscopy (FTIR), X-ray diffractometry (XRD) and Scanning electron microscopy (SEM). The crystalline size of the AgNPs was revealed with XRD. However, the SEM micrograph of AgNPs revealed the spherical shape with a non-uniform granular shape attributed to bio-mediated ionic gelation process. The FTIR spectra of AgNPs shown peaks at 1054 – 1645 cm^-1 suggesting the presence of phosphonate linkages between ammonium, -NH₃⁺ of chitosan and -PO₃^2- moieties of NaTPP during cross linking process. Electro-catalytic oxidation of glucose at the AgNPGCE surface and the mechanism involved in glucose oxidation was revealed via cyclic voltammetry. The AgNPGCE showed a better electrochemical response towards glucose. This glucose sensor showed high sensitivity at +0.54 V. A low detection limit of 1.22 µM (the confident level κ = 3), and wide linear range of 2 to 24 µM with a correlation coefficient of 0.9987 were obtained. The calculated parameters revealed that AgNPGCE had shown better overall electrochemical performance and response than enzymatic biosensor.

Abstract: Bioconversion of water hyacinth (Eichhornia crassipes) cellulose into glucose was successfully conducted by Trichoderma viride. Cellulose was isolated from water hyacinth by delignification. The delignification method is carried out for bond breaking of lignin, hemicellulose and cellulose. The Fourier Transform Infrared (FTIR) spectra of the delignification products confirmed that cellulose was successfully isolated. FTIR spectra showed the presence of peaks for the C=O and C=C groups, the C-H and C─O groups of polysaccharide bonds, and the C─O─C vibrational peak of pyranose ring. Cellulose was obtained in 58.84% yield. Cellulose was then converted into glucose through enzymatic processes by Trichoderma viride. Initially, these fungi are required to be adapted and rejuvenated with cellulose media. Gradual adaptation and rejuvenation aims to optimize the performance of fungi in converting cellulose into glucose. Cultures were incubated at 35°C and 120 rpm in an orbital shaker incubator. The FTIR spectra of glucose showed the presence of peaks for-OH alcohol and C=O bonds of glucose typical absorption peaks. Thus, the glucose conversion was successful. Water hyacinth can be a sustainable cellulose source for glucose synthesis in tropical and subtropical countries. Furthermore, water hyacinth has other advantages, such as its high breeding rate, availability, and low cost. Keywords: Eichhornia crassipes, glucose, water hyacinth, Trichoderma viridee

Abstract: A new synthetic procedure to Metal/metal sulfide hierarchical pore array composites was described. That is, a layer of Ni-Co-S nanoflakes was in situ constructed on the Ni ordered bowl-like micro/nanoarrays through a two-step electrodeposition method with the assistance of a colloidal sphere template. Such as-grown hierarchical composites could increase the specific surface areas and provide more active sites for electrocatalytic reactions. It exhibited a high catalytic activity to glucose, with a high sensitivity of 1210.1 μM‧mM^-1cm^-2 and a wide linear range from 0.5 μM to 2.0 mM. This work provides another candidate material for the development of planar non-enzymatic glucose sensors.

Abstract: Magnesium phosphate cements (MPCs) find application as alternative inorganic binders in construction, for crack repair and recycling of hazardous wastes. For the most common formulation, setting occurs through the reaction in water between magnesium oxide and potassium dihydrogen phosphate. The products include MgKPO₄·6H₂O (MKP) and an amorphous phase. Their use is somehow limited by the short working time and excessive release of heat. In this work, glucose has been introduced in the formulation of MPC to extend the setting time and modulate the rate of heat evolution. This can be considered an inexpensive and sustainable solution. The mechanism of action of the additive has been studied by investigating the reaction with isothermal conduction calorimetry, whereas the microstructure and phase composition of the obtained cements have been studied with scanning electron microscopy and X-ray powder diffraction, respectively. Results indicated that the additive influenced the reaction path thanks to the interaction at the molecular level with the dissolution process of magnesium oxide, as well as with the nucleation and growth of MKP. This has been confirmed by the changes induced in the size and shape of MKP crystals observed after the experiments conducted on diluted systems.

Abstract: A non-enzymatic glucose sensing nanomaterial which consists of the NiCo₂O₄ nanosheets grown on reduced graphene oxide (NiCo₂O₄@rGO) is synthesized by a simple co-precipitation procedure. Firstly, the morphology and composition of the NiCo₂O₄@rGO are analyzed. Subsequently, the glucose sensing characteristics of the NiCo₂O₄@rGO are researched by Cyclic Voltammetry and Amperometry. The test results show that the prepared NiCo₂O₄@rGO has excellent glucose sensing properties. In the two linear detection range of 0.01mM-5.50mM and 5.50mM-15.50mM, the sensitivity reaches 4372.9μA·mM^-1cm^-2 and 1686.1μA·mM^-1cm^-2, respectively. In addition, in order to reduce the cost of electrochemical testing and improve the convenience and practicability of detection, a portable potentiostatic glucose detection system based on three electrodes is designed. Through testing, it is found that the non-enzymatic glucose detection system based on NiCo₂O₄@rGO has good practical application potential in the field of glucose detection.

Abstract: S. platensis is a microalga that contains carbohydrate composition of 30.21% which makes it potential to be used as raw material for ethanol production. Hydrolysis of S. platensis is the first step for converting its carbohydrates into monosaccharides. The second step is fermentation of monosaccharides into ethanol. This research aims to study the effect of temperature and microalgae concentration on the hydrolysis of S. platensis using sulfuric acid as catalyst. This research was conducted using 300 mL sulfuric acid of 2 mol/L, hydrolysis temperatures of 70, 80 and 90 °C, and microalgae concentrations of 20, 26.7, and 33.3 g/L. The effect of temperature is significant in the hydrolysis of S. platensis using sulfuric acid. At microalgae concentration of 20 g/L and hydrolysis time of 35 minutes, the higher the temperatures (70, 80, and 90 °C), the more the glucose yields would be (8.9, 13.5, and 22.9%). This temperature effect got stronger when the hydrolysis was running for 15 minutes. Every time the hydrolysis temperature increased by 10 °C, the glucose yield increased by 13.0% at microalgae concentration of 33.3 g/L. At temperature of 90 °C and time of 35 minutes, the higher the microalgae concentrations (20, 26.7, and 33.3 g/L), the higher the glucose yields would be (25.5, 27.7, and 28.2%). The highest glucose concentration obtained was 2.82 g/L at microalgae concentration of 33.3 g/L, temperature of 90 °C, and time of 35 minutes.

Abstract: This research study about the influence of carbon concenttration as coating on electrical conductivity of LiFeSi_0.03P_0.97O₄/C. Synthesis of LiFeSi_0.03P_0.97O₄/C was carried out different carbon concentrations of 7, 9, and 11 wt%. The raw materials used are Fe₂O₃, Li₂CO₃, (NH₄)₂HPO₄, SiO₂ as ion Si doping, and glucose as carbon sources. The XRD analysis results showed that all the diffraction peaks in samples were the olivine LiFePO₄ phase. From the EIS result, Samples with the addition carbon concentration of 9 wt% produce the highest electrical conductivity values of 4.18 x 10^-7 S/cm.

Abstract: Organic field effect transistors (OFETs) as a sensor have gained interest of researchers due to its portable size and less expensive design in the field of medical diagnostic, food monitoring, chemical detection, wearable sensors, etc. In this present research work, we demonstrate the fabrication of OFETs from organic-inorganic SnO₂ nanoparticles tailored pentacenefor glucose detection. SnO₂ nanoparticles were synthesized bygreen method using Ficus religiosa leaf extract. The as-synthesized SnO₂ NPs with cassiterite crystal structure was analysed using X-Ray Diffraction (XRD) and the energy bandgap of ~3.8 eV was calculated using Tauc relation with absorption spectra so obtained from UV-vis spectroscopy (UV-vis). The structure and morphological analysis of SnO₂ NPs with size of ~15 nm was confirmed by Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) analysis. The sensor characteristics of OFET device fabricated using pentacene layer (soluble pentacene precursor of DMP) and as-synthesized SnO₂ nanoparticles confirmed the aqueous glucose (glucose in water) detection at room temperature (27 °C). The extracted electrical parameters such as mobility (μ), On-current (I_on), saturation current (I_Dsat) and the sensor response were discussed to support the sensor characteristics.

Abstract: In this study, the ultrafine copper-based powders were fabricated by a facile two-step chemical reduction method. Glucose (C₆H₁₂O₆) and ascorbic acid (AA) were taken as a pre-reductant and a second reductant, respectively. Polyvinylpyrrolidone (PVP) was applied as the capping agent. Effects of parameters, such as glucose content, PVP content and PH value on the ultimate reduction products were analyzed. Microstructure and composition of the products were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). It was found that when the amount of glucose was increased from half to full and then excessive, the powder gradually changed from flaky to spherical, from pure copper powder to a mixture of copper and cuprous oxide (Cu₂O). With the amount of PVP increasing from 0g to 0.64 g, the shape of the pure copper powder changed from cubic to spherical or HYPERLINK "javascript:void (0);" icosahedron. When the PH value changed from 10-14, the powder changed from spherical to regular octahedron and Irregular polyhedron, from pure copper powder to pure cuprous oxide powder. Therefore, copper-based powders with different morphologies and different compositions can be prepared by changing PH value and the amount of reductant.