Remarkable enhancement in sensor ability of polyaniline upon composite formation with ZnO for industrial effluents

Polyaniline emeraldine salt and Polyaniline Zinc Oxide composite are comprehensively studied to compare their sensing ability towards ammonia, acetone, methanol and ethanol. Sensing ability is evaluated through thermodynamic, geometric and electronic parameters. A number of orientations are evaluated in search for the lowest energy structure. The comparison of thermodynamic, geometric and electronic parameters of simple and composite sensors confirmed that composite sensor shows better sensing ability than simple PANI. Composite formation between polyaniline and zinc oxide is a thermodynamically feasible process with interaction energy of -42.8 kcal/mol. Both sensor shows highest interaction energy for ethanol among four analytes. Composite sensor shows almost twice the interaction with ethanol, methanol and acetone while 1.5 times the interaction energy for ammonia. The results of run simulations and subsequent calculations showed that in composite sensors, zinc oxide not only enhances the binding power of conducting polymer with analytes but also interacts directly with analytes. Strong hydrogen bonding as well as weak dispersion forces of attraction are responsible for the stability of composite and all complexes, as revealed by non-covalent interaction (NCI) studies. Acetone shows a different behaviour in composite sensor complex than other analytes.

An Ultrasensitive Magnetoelectric Sensor System For the Quantitative Detection of Liver Iron

Ultrasensitive magnetoelectric (ME) sensors have been developed using magnetostrictive/piezoelectric laminate heterostructures. This paper discusses a highly interdisciplinary design of a room temperature biomagnetic liver susceptometry system (BLS) based on the ME sensors. The ME-sensor based BLS maintains the ultrahigh sensitivity to detect the weak AC biomagnetic signals and introduces a low equivalent magnetic noise. The results reveal a "turning point" and successfully indicate the output signals to be linearly responsive to iron concentrations from normal iron level (0.05 mg_Fe/g_{liver phantom}) to 5 mg_Fe/g_{liver phantom} iron overload level (100X overdose). Further, the introduction of the water-bag technique shows the promise on the automatic deduction of the background (tissue) signal, enabling an even higher sensitivity and better signal-to-noise (SNR). With these improvements, it becomes feasible to get improved characterization flexibility and the field distribution mapping potential via signal processing from the correlations of multiple sensors in the system. Considering the wide presence of biomagnetic signals in human organs, the potential impact of such biomagnetic devices on medicine and health care could be enormous and far-reaching.