Amino acid functionalized ZrO₂ nanoparticles decorated reduced graphene oxide based immunosensor

Area of Science:

• Materials Science
• Nanotechnology
• Biosensors

Background:

• Developing sensitive and selective biosensors is crucial for detecting mycotoxins like ochratoxin A (OTA).
• Zirconium dioxide (ZrO2) and reduced graphene oxide (RGO) are promising nanomaterials for electrochemical applications due to their unique properties.

Purpose of the Study:

• To synthesize a novel ZrO2-RGO nanocomposite functionalized with l-methionine (Meth).
• To develop an immunosensor for the sensitive detection of ochratoxin A (OTA) using the fabricated nanocomposite.

Main Methods:

• One-step synthesis of ZrO2-RGO nanocomposite via hydrazine reduction of graphene oxide (GO) and in situ ZrO2 nanoparticle growth.
• Functionalization of ZrO2-RGO with l-methionine and subsequent immobilization of anti-OTA antibodies.
• Electrophoretic deposition of the Meth/ZrO2-RGO nanocomposite onto an ITO-coated glass substrate.

Main Results:

• ZrO2 nanoparticles (6 nm) were uniformly decorated on RGO sheets, preventing restacking and enhancing electrochemical properties.
• FTIR confirmed successful functionalization with Meth and biomolecules (anti-OTA, BSA).
• The fabricated immunosensor showed a wide linear detection range (1-20 ng mL-1), high sensitivity (4.8 μA ng-1 mL cm-2), and a low detection limit (0.079 ng mL-1) for OTA.

Conclusions:

• The Meth/ZrO2-RGO nanocomposite offers enhanced biocompatibility and wettability.
• The developed immunosensor provides a sensitive and reliable platform for ochratoxin A detection.