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Herein, a rapid and efficient molecular imprinted polymer (MIP) modified Ti3C2Tx-based electrochemical sensing platform was developed for levofloxacin detection (LEV). The MIP sensor was designed by depositing the synthesized Ti3C2Tx electrophoretically onto the indium tin oxide (ITO) glass surface, followed by electropolymerization of pyrrole as a monomer and LEV as a template molecule. Ti3C2Tx significantly enhances the electron transfer rate and offers a larger surface area to increase the number of imprinted sites for precise recognition of LEV. The fabricated sensor (MIP/Ti3C2Tx/ITO), under all optimized parameters, demonstrated superior selectivity with a low detection limit (LOD) of 0.76 pM and a linear relationship with LEV concentration ranging (1 pM–100 nM). Additionally, this newly developed sensor exhibited robust stability and sensitivity and successfully detected LEV in actual samples with satisfactory outcomes. [ABSTRACT FROM AUTHOR]

Various compositions in the system Sr1− x Gd x Ti1− x Mn x O3 ( x ≤ 0.50) were synthesized by solid-state ceramic route. Solid solution forms in all the compositions investigated. Crystal structure remains cubic up to x = 0.10 similar to SrTiO3, while for compositions with x ≥ 0.30, it becomes orthorhombic, similar to GdMnO3. Average grain size is small in all the compositions investigated, and it decreases with increasing x. For compositions with x ≤ 0.30, Seebeck coefficient is initially positive. It becomes negative at higher temperatures. For x = 0.50, it is negative over the entire temperature range of measurements. Immittance analysis shows the presence of two polarization processes, one due to grains and other due to grain boundaries. Results of DC resistivity, ρdc and Seebeck coefficient, α as a function of temperature show that in the samples with x ≤ 0.30, in the lowest temperature range conduction occurs due to hopping of holes among Mn+3 and Mn4+ ions, and for x = 0.50 it occurs due to hopping of electrons among Mn2+ and Mn3+ ions over the entire temperature range. In the intermediate temperature range, for x ≤ 0.30 the conduction occurs by hopping of electrons among Mn2+ and Mn3+ ions. For x = 0.01 and 0.05 conduction occurs due to diffusion of oxygen ions through doubly positively charged oxygen vacancies in the highest temperature range. [ABSTRACT FROM AUTHOR]

A few compositions in the valence compensated system Ba1− x La x Ti1− x Mn x O3 were synthesized by solid-state ceramic method to study the effect of co-doping lanthanum and manganese in equimolar amounts on dielectric behavior of BaTiO3. Compositions with x ≤ 0.10 have shown solid solution formation. Compositions with x ≤ 0.05 are found to have tetragonal structure at room temperature while composition with x = 0.10 is cubic. Plots of relative dielectric constant, εr versus temperature for composition with x = 0.01 show dielectric anomalies around 376 ± 2, 264 ± 2 and 179 ± 2 K which correspond to cubic to tetragonal ( T C–T), tetragonal to orthorhombic ( T T–O) and orthorhombic to rhombohedral ( T O–R) transition, respectively, similar to BaTiO3. Curie temperature has been found to decrease with increasing concentration of lanthanum and manganese simultaneously in barium titanate. The broadening in the dielectric peak at cubic to tetragonal ( T C–T) transition temperature increases with increasing x. For x = 0.10, only one anomaly at 100 K is observed in its εr versus T plots. The observation of this single anomaly may be due to pinching effect of the substitutions on the three phase transitions. [ABSTRACT FROM AUTHOR]

An attempt has been made to investigate the solid solubility limit between barium titanate, BaTiO3 and lanthanum chromite, LaCrO3. Compositions with x ≤ 0.15 have shown solid solution formation in the system Ba1− x La x Ti1− x Cr x O3. Compositions with 0.01 and 0.05 are found to have a tetragonal structure, whereas those with x = 0.10 and 0.15 are found to have a cubic structure at room temperature. Dielectric measurements have been carried out at different frequencies in the temperature range 100–550 K. Plots of εr versus temperature for composition with x = 0.01 show dielectric anomalies at 376 K ( T C-T) and 275 ( T T-O) where T C-T and T T-O denote the temperature for cubic to tetragonal and tetragonal to orthorhombic transition. Dielectric anomaly corresponding to the ferroelectric to paraelectric transition has been found to shift to lower temperatures with increasing concentration of lanthanum and chromium. For compositions with x ≤ 0.05, T C has been found to be frequency independent while for x = 0.10 and 0.15, T C has been found to be frequency dependent in a manner similar to relaxor ferroelectrics. [ABSTRACT FROM AUTHOR]

Electrical transport behaviour of the valence compensated system Ca1− xLa xTi1− xCr xO 3( x≤ 0.50) has been investigated by studying the Seebeck co-efficient, DC and AC conductivity as a function of temperature. Seebeck co-efficient, DC conductivity of different compositions has been measured in the temperature range 300 K–1000 K. AC conductivity for different compositions were determined in the temperature range 100–550 K and frequency range 10 Hz–10 MHz. Positive values of Seebeck co-efficient show that holes are the majority charge carriers. Conduction seems to occur by correlated barrier hopping of holes among Cr3+and Cr4+ions or VO •and VO ••. Almost equal values of activation energies obtained for DC conductivity and dielectric relaxation process show that both the processes occur by the same mechanism. [ABSTRACT FROM AUTHOR]