Study of Thermoluminescence and Optically Stimulated Luminescence Properties of Synthesised CaB2O4 Nanoparticles Doped with Copper.

CaB2O4 nanorods doped with different concentrations of Cu were prepared by using co-precipitation method. The recorded Thermoluminescence (TL) and Optically stimulated luminescence (OSL) of CaB2O4:Cu samples for different concentrations of Cu irradiated with 6 Gy of X-Ray shows that 0.05 at.wt% of Cu concentrations have higher sensitivity. The TL and OSL kinetic parameters of glow curves were evaluated using "tgcd" and conventional fitting methods. The TL glow curve of the CaB2O4:Cu have three individual glow peaks with maximum peak temperatures at 404.50, 453.04 and 484.02 K respectively. The OSL glow curves of the CaB2O4:Cu nanoparticles follow non-first order kinetics which can be fitted with the sum of two first order decay curves.

Investigation of Thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) Properties of Dy3+ Doped CaB4O7 Nanoparticles.

CaB4O7 nanoparticles doped with different concentrations of Dy3+ were prepared by using solution combustion method. The recorded Thermoluminescence (TL) and Optically stimulated luminescence (OSL) of CaB4O7:Dy samples for different concentrations of Dy3+ irradiated with 6 Gy of X-Ray shows concentration quenching effect above 0.05 at.wt% of Dy3+ concentrations. The TL and OSL kinetic parameters of glow curves were evaluated using "tgcd" and conventional fitting methods. The TL glow curve of the CTB:(0.05%)Dy have five individual glow peaks with maximum peak temperatures at 410, 470, 525, 563 and 593 K. TL Dose response of the X-Ray irradiated CTB:(0.05%)Dy is also found to be linear in the range of 1 Gy to 50 Gy. The OSL glow curves of the CTB:Dy nanoparticles follow non-first order kinetics and can be fitted with the sum of three first order decay curves. Fading characteristics of the TL and OSL signals are studied for 40 days and found to be very stable.

Ruthenium complex based nanocomposite film with enhanced and selective electrochemical sensing of bifenthrin pesticide.

Bifenthrin (BF), a widely used pyrethroid pesticide in farming, lacks highly sensitive and selective sensors despite its extensive application. Ruthenium complexes are very effective for selective sensing applications but suffer from structural instability at elevated conditions, electrochemical activity, and the use of costly electrolytes. This work improves their electrochemical activity and mechanical strength by incorporating silver nanowires and replacing the costly electrolyte with abundant KCl + PBS, resulting in enhanced signal performance. Herein, a ruthenium complex containing composite film was immobilized on a platinum (Pt) electrode using Langmuir Blodgett technique. The fabricated sensor has been characterized by differential pulse voltammetry (DPV) based electrochemical technique. The BF pesticide sensing parameters, including the limit of detection (LOD), linear range (LR), and sensitivity, were evaluated using SWV, DPV, and CV techniques. Among these, the DPV technique demonstrated the best performance, achieving a sensitivity of 0.648 µA cm-2 µM-1, a LR of 1-10 µM, and a LOD of 1 µM. The relative standard deviation (RSD) values using DPV are found to be 6.3% (repeatability study), 3% (reproducibility study), 8% (metal ion interference), 5% (organic species interference), and 2% (real sample study), which are much lesser than the World Health Organization (WHO) recommendation of RSD value on the pesticide (i.e. 20%). The BF sensor demonstrated a selectivity of 2× difference of peak height response compared to similar pesticides. The reported pesticide sensor will open new options for sensor research using metal complex-based LB film nanocomposite.