Amine Functionalized Gadolinium Oxide Nanoparticles-Based Electrochemical Immunosensor for Cholera.

Herein, we report the synthesis and functionalization of gadolinium oxide nanoparticles (Gd 2 O 3 NPs) to fabricate a highly efficient immunosensor for the detection of Vibrio cholera toxin (CT). Gd 2 O 3 NPs were produced in a straightforward manner utilizing the microwave irradiation technique using a domestic microwave oven. X-ray diffraction, transmission electron microscopy, and spectroscopic techniques were used to characterize the structural and physical aspects of Gd 2 O 3 NPs. The Gd 2 O 3 NPs were then functionalized with 3-(Aminopropyl) triethoxysilane (APTES) and electrophoretically deposited onto an ITO-coated glass substrate. The anti-CT monoclonal antibodies were covalently attached to the APTES-Gd 2 O 3 /ITO electrode via EDC-NHS chemistry, followed by bovine serum albumin (BSA). For CT detection, electrochemical response experiments using BSA/anti-CT/APTES-Gd 2 O 3 /ITO immunoelectrodes were carried out (5-700 ng mL -1 ). The immunoelectrode demonstrated an outstanding electrochemical reaction against CT, with a sensitivity of 8.37 mA ng -1 mL cm -2 and a detection limit of 1.48 ng mL -1 .