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).