Application of Amine and Copper Doped Magnesium Oxide Nanoparticles in Electrochemical Immunosensors for Detecting Brucella abortus

Herein, we report the synthesis, characterization, and applications of electrochemical immunosensors of amine and copper doped magnesium oxide (MgO) nanoparticles. The synthesized nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-Visible and Fourier transform infrared (FTIR) spectroscopy. For application, the synthesized nanoparticles were used as an efficient matrix to fabricate electrochemical immunosensors for the detection of Brucella abortus. The immunosensor devices were fabricated by printing thick films of synthesized nanomaterials on gold-plated working electrodes prepared by screen printing method. The fabricated electrochemical devices were tested with different Brucella abortus concentration in the range of 1x10(3) CFU/ml to 2x10(6) CFU/ml in phosphate buffer (pH = 7.2, 0.1 M) in presence and absence of antibody. Interestingly, a detectable change in the redox peak currents was recorded with Brucella abortus in presence and absence of antibody. The detailed sensing results revealed that the fabricated immunosensor device based on copper (Cu) doped MgO nanoparticles exhibited highest sensitivity (2.5 times; 2.86 nA/1000 CFU/ml) after antibody immobilization. Further, in order to study the charge transfer characteristics, the fabricated device was measured at various scan rates (10 mV/s to 100 mV/s) by fixing the concentration of Brucella abortus. Finally, the electrochemical impedance spectroscopy (EIS) experiments were also conducted to study the charge transfer resistance by keeping the frequency range of 0.1 Hz to 10(6) Hz and E-start of 0.5 V. To check the specificity of the fabricated immunosensors, interference studies were also performed and presented in this paper.