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Graphene-Based Waist-Enlarged Optical Fibre Sensor for Measurement of Sucrose Concentration
摘要： A novel sucrose sensor based on graphene-coated optical fibre with waist-enlarged bitapers as Mach-Zehnder interferometer is proposed and demonstrated. The sensor is formed by arc fusion splicing a photonic crystal fibre (PCF) sandwiched between two single-mode fibres (SMFs). The intermodal interference is achieved by two waist-enlarged fibre tapers at the coupling points between the PCF and two SMFs. The result shows that the dips of transmission spectra exhibit blue shift with the concentration increase of the sucrose, and the sensor has a high linear response (R2 = 0.98233) to sucrose with an excellent sensitivity of 3.36 pm/ppm in the range of 0–230 ppm. Additionally, the surface adsorption mechanism is also discussed. Such easily fabricated, cost-effective and small volume fibre interferometer could be used for sucrose sensing applications.
关键词： Graphene,Sucrose Sensor,Blue Shift,Waist-Enlarged Bitapers,Mach-Zehnder Interferometer
更新于2025-11-28 14:23:57
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A novel luminescent sensor for disaccharide detection in food: Synthesis and application of a water-soluble rod-coil ionic block copolymer
摘要： A simple and low cost method for detecting disaccharide in food product is important for people who need control the consumption of saccharides in daily life. In this study, a water soluble rod-coil ionic block copolymer poly[2,7-(9,9-dihexyl-fuorene)]-b-cationic quaternized-poly[2-(dimethylamino)ethyl methacrylate] (PF-b-PDI) was employed as luminescent sensor for detection of lactose, sucrose and maltose in food. It was found that the PF-b-PDI could emit vision fluorescence with the existence of hydroquinone (HQ) in aqueous, but would be quenched by the oxidization of hydrogen peroxide (H2O2). The glucose oxidase (GOx) could be used for catalyzing the glucose to generate the H2O2. And the sucrase, maltase and lactase could respectively catalyze sucrose, maltose and lactose to glucose. With the selectivity and catalyst of enzyme, the PF-b-PDI aqueous blend with HQ showed fluorescence sensitive to sucrose, maltose and lactose with detection limit value of 1.36 μM, 1.09 μM and 3.08 μM, respectively. Moreover, the detection of lactose in milk samples by this method just revealed 0.44% of average deviation compared to standard lactose solution, which mean this method was suitable for detecting lactose in milk.
关键词： maltose,rod-coil ionic block copolymer,lactose,sucrose,luminescent sensor
更新于2025-09-23 15:22:29
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Pseudo-Continuous Flow FTIR System for Glucose, Fructose and Sucrose Identification in Mid-IR Range
摘要： In this paper, we present a new FTIR-based micro?uidic system for Glucose, Fructose and Sucrose detection. The proposed micro?uidic system is based on a pseudo-continuous ?ow coupled to a microscope-FTIR instrument. The detection and characterization of sugar samples were performed by recording their absorption spectrum in the wavelength range 700–1000 cm?1 of the Mid-IR region. The proposed pseudo-continuous ?ow system is designed to improve the uniformity of the sample distribution in the analyzed area versus conventional systems. The obtained results for different sugars concentrations, show a very low measurement error of 4.35% in the absorption peak intensity, which is ten times lower than the error obtained using the conventional measurements.
关键词： mid-IR absorption spectroscopy,absorption spectrum,FTIR spectroscopy,microscopy-FTIR spectrometer,sugars detection and quanti?cation,Glucose,Fructose,Sucrose,pseudo-continuous ?ow
更新于2025-09-23 15:21:21
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Biomolecular interaction and kinematics differences between P25 and E171 TiO2 nanoparticles
摘要： Titanium dioxide (TiO2) nanoparticles (NPs) are used abundantly as food additives (E171). For the purpose of risk assessment, it is imperative to understand the behavior of these nanoparticles in a food relevant environment, and their consequent toxicology impacts. However, most of such studies use model TiO2 NPs (P25) as substitutes for E171. To understand the suitability of this approach, we investigated the functional behavior of E171 and P25 in solutions of bovine serum albumin (BSA) and sucrose as model food ingredients. Our data showed that E171 were better dispersed in BSA than P25. In sucrose, E171 displayed a reduction in agglomerated size while P25 agglomerated extensively. Adsorption studies showed that P25 attracted more pronounced corona formation per unit mass of material compared to E171. In vitro sedimentation, diffusion and dosimetry (ISDD) results demonstrated that the time-weighted dosage of E171 was more than two-folds higher than P25, implying that any test performed using P25 to model E171 would underestimate actual dosage and potential toxicity. Taken collectively, this study demonstrated the specificity of TiO2 nanoparticle interaction with food ingredients, and the importance of using food-grade E171 TiO2 for food-relevant toxicological assessments.
关键词： ISDD,Nanoparticles,Titanium dioxide,Sucrose,Corona,Protein
更新于2025-09-23 15:21:21
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Influence of osmolytes on the stability of thylakoid‐based dye‐sensitized solar cells
摘要： In recent years, there has been considerable interest in incorporating naturally occurring components of the photosynthetic apparatus into man‐made solar cells, because of the high quantum efficiency of photosynthetic reaction centers. One hurdle to overcome regarding the use of native membranes in these devices is their limited lifespans. In this study, we used stabilizers to increase the long‐term viability of biomolecules in vitro, thereby alleviating this challenge. In this regard, it is known that osmolytes, such as glycine betaine (GB) and sucrose, preserve photosynthetic activity in isolated photosystems. Upon investigation of the thermal protection properties of GB and sucrose in thylakoid‐based dye‐sensitized solar cells, we report that the addition of GB and sucrose to the thylakoid photosensitizer maintains nonzero photocurrent in the thylakoid‐based solar cell upon heating to 50°C. At 50°C, the GB‐containing cell displayed about a fourfold increase in photocurrent than the control cell, in which the photocurrent was decreased to nearly zero. The addition of 0.5M and 1M sucrose has respectively caused nearly 40% and 70% increases in photoinduced electron transfer activity over the control at 35°С. Similarly, though to a lesser extent, 1M GB caused an approximate 40% increase in electron transfer activity as well. Moving forward, this approach will be extended to alternative membrane protein isolation strategies, allowing for an accurate comparison with traditional detergent‐isolated complexes, with the ultimate goal of developing a cost‐effective and sustainable solar cell.
关键词： solar cell,stabilization,thylakoid membrane,sucrose,glycine betaine
更新于2025-09-19 17:13:59
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[IEEE 2019 International Workshop on Fiber Optics in Access Networks (FOAN) - Sarajevo, Bosnia and Herzegovina (2019.9.2-2019.9.4)] 2019 International Workshop on Fiber Optics in Access Networks (FOAN) - Realization of sucrose sensor using photonic waveguide: An application to biophotonics
摘要： A photonic waveguide sensor is explored in the present paper for effective sensing of sucrose concentration in an aqueous solution at a wavelength of 1550 nm by employing a 1-D photonic waveguide structure. The proposed structure comprises three layers, out of which odd layers are considered to be an InAs compound semiconductor having thickness of 700nm each whereas an even layer is air having thickness of 300 nm. Additionally, the effect of concentration variation of sucrose is theoretically examined with reference to reflected intensity, diffraction loss and transmitted intensity at the aforementioned waveguide. Reflected intensity from the said structure is computed through band gap analysis by a manipulating finite difference time domain (FDTD) technique, whereas diffraction loss and transmitted intensity are computed through numerical formulations. Further, simulation for diffraction loss with respect to different sucrose concentration has been carried out and interestingly the upshots revealed logarithmic deviation of diffraction efficiency with reference to variation in sucrose concentration from 10 gm/100ml to 70 gm/100ml. Apart from this, it is also revealed that there exists noteworthy shifts in both reflected as well as transmitted intensity with rise in sucrose concentration. Additionally, it is affirmed that both reflected light intensity and transmitted light intensity can be nicely fitted linear relationship having R2=0.998 and with a precise R2=0.9919 respectively, which claim an accurate sensing of sucrose concentration by using the proposed semiconductor based photonic waveguide and find applications in biophotonics.
关键词： band gap,sucrose sensing,photonic waveguide,FDTD
更新于2025-09-12 10:27:22
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Electrospray-Surface Enhanced Raman Spectroscopy (ES-SERS) for probing surface chemical compositions of atmospherically relevant particles
摘要： We present electrospray-surface enhanced Raman spectroscopy (ES-SERS) as a new approach to measuring the surface chemical compositions of atmospherically relevant particles. The surface-sensitive SERS is realized by electrospraying Ag nanoparticle aerosols over analyte particles. Spectral features at v(SO42-), v(C-H) and v(O-H) modes were observed from the normal Raman and SERS measurements of laboratory-generated supermicron particles of ammonium sulfate (AS), AS mixed with succinic acid (AS/SA) and AS mixed with sucrose (AS/sucrose). SERS measurements showed strong interaction (or chemisorption) between Ag nanoparticles and surface aqueous sulfate [SO42-] with [SO42-]AS/sucrose > [SO42-]AS/SA > [SO42-]AS. Enhanced spectra of the solid AS and AS/SA particles revealed the formation of surface-adsorbed water on their surfaces at 60% relative humidity. These observations of surface aqueous sulfate and adsorbed water demonstrate a possible role of surface-adsorbed water in facilitating the dissolution of sulfate from the bulk phase into its water layer(s). Submicron ambient aerosol particles collected in Hong Kong exhibited non-enhanced features of black carbon and enhanced features of sulfate and organic matter (carbonyl group), indicating an enrichment of sulfate and organic matter on the particle surface.
关键词： Electrospray-Surface Enhanced Raman Spectroscopy,succinic acid,atmospherically relevant particles,surface chemical compositions,ES-SERS,sucrose,Ag nanoparticles,surface-adsorbed water,organic matter,ammonium sulfate,black carbon
更新于2025-09-09 09:28:46
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Synthesis and Characterization of Tio2/C Composite for Photocatalytic Degradation of Dyes.
摘要： Titanium dioxide TiO2 nanoparticles have moderate catalytic activity due to its wide band-gap and high rate of electron-hole recombination [1]. The TiO2 electrical conductivity poor is improved by mixing with other materials. Therefore, TiO2 based nanocomposites have been synthesized to increase the photocatalytic activity, as well as their structural characteristics and electrochemical performance, using dopants like carbon, nitrogen, sulfur and others. TiO2/C composite has been proven to be a promising photocatalyst for pollutants, due to C-doping, morphology, structure and mixed phases [1]. Carbon precursors are reported to synthesize TiO2/C, such as: glucose, oleic acid, carbon nanofiber, graphene oxide, activated carbon, carbon nanotubes, graphite, resorcinol and formaldehyde. Dyes used for industries, are significant sources of environmental pollution, because they are non-biodegradable [2]. Methyl orange (MO) and methyl blue (MB) have been used to help determine the activity of the photocatalyst [3]. The reagents used were: anatase powder 99.8% (metals basis), sucrose (99.5%), H2SO4 (65% wt), distilled water, MO (MW=327.33g/mol) and MB (MW=319.85g/mol). TiO2/C composites were synthesized via infiltrating sucrose into anatase. In a typical synthesis, anatase (A) and sucrose (S) with molar ratio of A/S=6, sulfuric acid and distilled water were mixed completely. The mixture was then put in a drying oven, treated at 100°C for 6h and subsequently at 160°C for 6h. The resulting brown precursor powder was carbonized in a tubular furnace at 800°C for 1h in argon atmosphere. Rigaku D-Max 2200 difractometer was used to obtain XRD patterns using Cu Kα radiation. The surface morphology and the crystalline phases were examined with Field Emission Transmission Electron Microscope, JEM 2010F JEOL. The photocatalytic activity was tested for degradation of MB and MO with an initial concentration of 20 ppm, using 0 and 0.34 g/L of TiO2/C, under radiant flux provided by 175 W UV. The MB and MO concentrations were measured by UV–vis spectroscopy (Aiglet-Vis spectrophotometer). The XRD patterns of TiO2/C composite is shown in Fig. 2, in which all the characteristic diffraction peaks of the TiO2/C composite can be respectively indexed with planes of anatase phase of TiO2 (JCPDS No. 21-1272). Moreover, a small peak at 11.5° is observed, characteristic of weakly ordered graphitic microstructure, indicating the trace amount of graphite in the composite [4]. No significant peaks of carbon or rutile are observed after the precursor powders are heat treated under argon atmosphere, which suggesting its amorphous nature and confirmed the high purity of the TiO2/C composite [5], because impurities have been reported due to the transformation from anatase to rutile phase [1]. The broad diffraction peaks indicate the sample’s nanocrystalline nature. Fig. 3a shows the micrographs of TEM bright field of powders; it is clearly seen that the TiO2/C composite powders have mostly spherical morphology. Further, it can be estimated that the particle size of samples is of the microscale order with grain size of the range of 20-30nm. Fig. 3b shows the atomic structure and the crystallinity of TiO2/C composite through HRTEM. The insert image shown in Figure 3b give the corresponding Fast Fourier Transform (FFT) pattern of the anatase; this pattern displays (101) and (200) planes from the interplanar spacing of 0.352 and 0.189 nm respectively (JCPDS No. 21-1272). The results of XRD concurred with the electron diffraction pattern created by FFT from HRTEM. The degradation percentage for MO and MB were 99.95 and 99.99 % at 15 min on TiO2/C whereas 86 and 81 % at 90 min for MB and MO in the absence of catalyst is illustrated in Fig. 5. TiO2/C composite was synthetized using anatase and sucrose by obtaining a precursor powder at low temperature (160°C), which is carbonized at 800°C in argon atmosphere. The XRD analysis reveals that the TiO2/C composite is a phase anatase unique structure with high crystallization, which had no impurities, but it showed a trace amount of graphite in the composite. The TiO2/C composite were found to be efficient catalyst for the photodegradation of MB and MO dyes under UV irradiation. The reaction was found to follow pseudo-first order kinetics described it well. This method could be extended to synthesize a variety of other composites for photocatalytic degradation of dyes.
关键词： anatase,TiO2/C composite,dyes,photocatalytic degradation,sucrose
更新于2025-09-04 15:30:14