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This paper reports a rapid microwave biosensor to check forEscherichia coli contamination in water samples, which can thereafter be extended for testing of other microbes as well. The sensor is a 3x3 array of polystyrene cylinders 8 of which are filled with poly vinyl chloride solid cylinders with the centre hollow cylinder holding the sample to be investigated. The sensor takes only 4-5 minutes for sensitive detection of up to 1-2 Colony forming units (CFU) of Escherichia coli. The present technique thus proves better than all presently available techniques in terms of both sensitivity and resolution and speeds up the detection process manifold. Microwave bio-sensing thus presents itself as a promising solution for rapid, sensitive and user-friendly detection of water contamination.

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In this paper we describe a Whispering gallery mode (WGE 800 ) dielectric resonator method with a cheap polycarbonate sample holding disk for sensing variation in picomolar (pM) concentration of Insulin in hepes buffer solution. For investigation of pM concentration Insulin solution mainly three different volumes i.e. 0.4, 0.8 and 6.4 microliter volume of sample solutions loaded on sample holding disk (SHD) and analyzed. Obtained results shows that calculated loss tangent of solution is sensitive to variation in pM concentration of Insulin with no shift in frequency. Moreover, small response time, low sample volume and its ability to sense losses in pM concentration of Insulin in liquid medium makes this method ideal insulin biosensor for medical diagnostic purpose.

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In this paper characterization of dielectric materials in liquid and powder phase using concentric closed and split ring resonators of length λ, λ/2, and λ/4 is reported. Experimental results have been validated by simulations and theoretically modeling. Sensitivity of the resonator with closed rings was maximum. Experimentally extracted values of dielectric constant of ferrite ranged from 14.05 to 15.1 with closed ring resonators and from 13.6 to 14.02 with split ring resonator, respectively. For spirulina platensis the dielectric constant was lying in the range 1.78–1.93 and 1.74–2.04 with closed ring and split ring resonators, respectively. The values extracted experimentally are in good agreement with simulation and theoretically found values. However, the values obtained from closed ring resonator were in agreement with the dielectric constant values of ferrite and spirulina platensis.

In this paper, we used the distinguishable surface charge and mass of different bacterial strains for label free detection and differentiation of pathogen through impedance and magnetohydrodynamic (MHD) analysis. For the isolation of Escherichia coli and Staphylococcus aureus, functionalized magnetic nanoparticles (MNPs) were used. The proposed method is aimed at minimizing extensive chemical preparation and labor intensive conventional microbiological processing thereby reducing the detection time. Pathogens isolated from broth cultures using the MNPs were subjected to impedance rate measurement through an arduino-based automated impedance sensor along with differentiation on the basis of Larmor's motion through the MHD approach. The proposed method evidently reports that the two bacterial species bind differently to the MNPs giving appreciable variation in the impedance rate increment for a dc electric field of 250V/m. In addition to this, cross-field drift through 171.4 V/m electric field and a normal magnetic field of 500 Gauss led to lump formation in S. aureus but had no such effect on E. coli. The mobility analysis of the two species of bacteria was also carried out by observing the gyration of bacteria through naked eyes. The mobility of lumped bodies of S. aureus was of the order 10 m/V sec; whereas for dispersed E. coli, it was 10 m/V sec.

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