Biocompatible capped iron oxide nanoparticles for Vibrio cholerae detection. (8th April 2015) - Sharma, Anshu
Abstract: We report the studies relating to fabrication of an efficient immunosensor for Vibrio cholerae detection. Magnetite (iron oxide (Fe3 O4 )) nanoparticles (NPs) have been synthesized by the co-precipitation method and capped by citric acid (CA). These NPs were electrophoretically deposited onto indium-tin-oxide (ITO)-coated glass substrate and used for immobilization of monoclonal antibodies against Vibrio cholerae (Ab) and bovine serum albumin (BSA) for Vibrio cholerae detection using an electrochemical technique. The structural and morphological studies of Fe3 O4 and CA-Fe3 O4 /ITO were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS) techniques. The average crystalline size of Fe3 O4, CA-Fe3 O4 nanoparticles obtained were about 29 ± 1 nm and 37 ± 1 nm, respectively. The hydrodynamic radius of the nanoparticles was found to be 77.35 nm (Fe3 O4 ) and 189.51 nm (CA-Fe3 O4 ) by DLS measurement. The results of electrochemical response studies of the fabricated BSA/Ab/CA-Fe2 O3 /ITO immunosensor exhibits a good detection range of 12.5–500 ng mL −1 with a low detection limit of 0.32 ng mL −1, sensitivity 0.03 Ω /ng ml −1 cm −2, and reproducibility more than 11 times.