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This study sought to detect the presence of sucrose as an adulterant in selected honey varieties from different floral origins by employing Electrical Impedance Spectroscopy (EIS) technique which has been simultaneously supported by Fourier Transform-Mid Infrared Spectroscopy (FT-MIR) measurements to provide a rapid, robust yet simple platform for honey quality evaluation. Variation of electrical parameters such as impedance, capacitance and conductance for 10%, 20%, 30%, 40%, 50%, 60% and 70% (w/w) sucrose syrup (SS) adulterated honey samples are analyzed and their respective current-voltage (I-V) characteristics are studied. Capacitance, conductance and net current flowing through the system are observed to decrease linearly whereas system impedance has been found to increase similarly with the increase in adulterant content. Also, FT-MIR measurements in the spectral region between 1800 cm −1 and 650 cm −1 reveal the increment of absorbance values due to the addition of SS. Full-Width-at-Half-Maximum (FWHM) is estimated from the spectral peak 1056 cm −1 for all pure and adulterated honey samples and is observed to be linearly increasing with increase in adulterant content. Finally, the coefficient of sensitivity has been extracted for all varieties of honey considered in terms of the measured conductance values. [ABSTRACT FROM AUTHOR]

An analytical model is developed to describe the dielectric behaviour of pure DI water-sucrose solution in which sodium carbonate (Na 2 CO 3 ) is added as an adulterant. Relative impact of constituent dipoles has been emphasized and multi-body dipolar interactions have been explicitly considered for a comprehensive analysis of such a system in thermal equilibrium. The theoretical model is verified with experimental data obtained from the impedance and capacitance based spectroscopic measurements. The impedance and capacitance of DI water-sucrose solution are observed to vary in a quasi-oscillatory nature with different sucrose content in it. However, such variation shows a decreasing trend and linear nature for a minimum of 1% adulterant content. The system impedance decreases and capacitance increases with increasing adulterant wt% for a given sucrose concentration. For the 0% of adulterant in the solution with varying sucrose content, the impedance and capacitance have varied from 140.12 kΩ to 236.17 kΩ and 40.7 pF to 44.2 pF, respectively. However, such values change from 111 Ω to 157 kΩ and 42.5 pF to 72 μF for the adulterant content up to 5%. [ABSTRACT FROM AUTHOR]

In the current article, a substrate engineered patterned array of square-shaped features of size 1.5 μm × 1.5 μm comprising of <111>/[100]-planes of p-Si substrate has been developed by employing electron beam lithography assisted selective anisotropic wet etching. The etching of such planes is performed by combining the effect of KOH as the chemical etchant and Pt/Pt 3 Si as the mask with its catalyzing properties for the etching reaction. The regular array of exposed <111>/[100]-planes is confirmed by FESEM imaging and X-ray diffraction study. The formation of a 'virtual hetero-junction' at <111>/[100] interface is characterized by in-situ current-voltage measurement within the FESEM chamber. Such surface engineered Si-substrates can be utilized for multifaceted applications by fabricating different types of electronic, optoelectronic and bio-sensing devices. • A substrate engineered sub-μm patterned array of square groves of <111>-planes on a [100]-Si substrate is fabricated. • The patterning is performed by electron beam lithography-assisted selective anisotropic wet etching. • KOH etching of Si substrate is patterned and catalyzed by developing a Pt/Pt 3 Si nano-porous mask. • The Si < 111>/[100] ' virtual hetero-junction ' is explored by in-situ electrical measurement within the FESEM chamber. • Such surface engineered Si-substrates can be utilized as a template for electronic, optoelectronic and bio-sensing devices. [ABSTRACT FROM AUTHOR]

The impedance, capacitance and conductance of deionized waterglucose polar solution is measured by employing impedance spectroscopy and a quasi-oscillatory nature of variation with glucose content in the solution is observed. Such quasi-oscillatory nature is attributed to the randomly distributed water-water, waterglucose and glucose-glucose dipole interactions at the molecular level in the solution. A relevant analytical model is developed on the basis of such random distribution of the molecular dipoles and the experimental data agree well with those obtained from the theoretical model. The electrical parameters are measured in the frequency range of 100Hz to 4MHz for the volume fractions of glucose with respect to water in the range of 0.1 to 0.5. The impedance, capacitance and conductance are obtained to be in the range of 1.03 kΩ - 112 kΩ, 34.9 pF - 1.66 nF, and 8.95 μS - 52.9 μS respectively for the glucose volume fraction range considered. [ABSTRACT FROM AUTHOR]

The current article demonstrates a novel diagrammatic approach for the detection and quantification of polar and non-polar/ionic adulterants in milk by employing electrical impedance spectroscopy (EIS). For such study, some commonly used milk adulterants including melamine, starch, urea, allantoin, cyanuric acid, benzoic acid, ammonium sulphate and sodium bicarbonate are incorporated in a controlled manner in the pure milk sample. The presence of such adulterants in milk is confirmed by Fourier transform mid-infrared (FT-MIR) spectroscopy prior to impedimetric measurements. A Pt/Teflon/SiO2/Si biosensor device is fabricated for EIS measurement where the combination of SiO2 and Teflon layer thicknesses are optimized to obtain an appropriate hydrophobicity/dielectricity for the liquid milk samples. The EIS study shows an opposite trend in the variation of electrical impedance, capacitance and conductance for the polar samples in comparison to non-polar/ionic adulterants, upon their controlled addition from 0.5 to 9 (mg/g). Such results are utilized for detection and quantification of the milk-adulterants by developing a diagrammatic approach based on impedimetric phase angle-modulus mapping. Such diagrammatic impedance spectroscopy provides a generic scheme for a rapid, cost-effective and point-of-care detection and quantification of adulterants in milk which can be further extended to other bio-consumables. • EIS detection scheme to identify polar and non-polar/ionic adulterants in milk. • Pt/teflon/SiO2/Si biosensor device fabricated for EIS measurement of liquid sample. • The device can detect milk adulterant concentration ranging from 0.05 to 0.9% (w/w). • Impedimetric phase angle-modulus diagram can map various adulterants in milk. [ABSTRACT FROM AUTHOR]

Dielectric properties of a living biological membrane play crucial role indicating the status of the cell in pathogenic or healthy condition. A distinct variation in membrane capacitance and impedance was observed for peripheral blood mononuclear cell (PBMC) suspensions for diabetic and diabetic-dyslipidemic subjects compared to healthy control. Low frequency region were explicitly considered in electrical analysis to address complex membrane dielectric factors that alter the system capacitance of a PBMC suspension. Such variation was marked in size, morphology and membrane function of PBMCs for control and diseased cases. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies reveal significant alteration in surface morphology of PBMCs in diseased condition. Side scatter of flow cytometry reveals complexity of PBMCs in diseased condition. Changes in size between groups were not found by SEM and forward scatter. Functional alteration in PBMCs was manifested by significant changes in cell membrane properties like Na + , K + ATPase and Ca 2+ , Mg 2+ ATPase activity, reduced plasma membrane fluidity and changes in intracellular Ca 2+ content, which bear significant correlation in diabetic and diabetic dyslipidemic subjects. Therefore, dielectric parameters of PBMCs in diabetic-dyslipidemic challenges may led to interesting correlation opening the possibility of identifying crucial signature biomarkers. [ABSTRACT FROM AUTHOR]