This thesis is an investigation of a sandwich-based electrochemical immunosensor for detection of avian influenza virus (AIV) strains H5N1, H4N6, and H9N2. This sensor was developed using goldgraphene nanocomposites, immobilized viral antibodies, and cadmium telluride (CdTe) quantum dot electrochemical tagging. The nanocomposites were formed by the simultaneous reduction of a gold salt and graphene using hydroquinone as the reducing agent, thus producing non-spherical gold nanoparticles on graphene sheets. Viral antibodies were immobilized on nanocomposites and CdTe quantum dots through N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide and N-hydroxysuccinimide chemistry. Cyclic voltammetry studies were used to validate the detection of H5 surface protein and H4N6 inactivated virus. The immunosensor detected H5 protein in phosphate buffer solution (pH 7.4) with a limit of detection (LOD) of 10 fg/mL and a linear detection range was established for 10 ng/mL to 10 pg/mL. The biosensor detected H4N6 and H9N2 viruses in three parts diluted whole chicken blood with a LOD of 1.28x10-7 hemagglutinating units (HAU). Commercial ELISA testing for H4N6 showed a limit of detection of 0.128 HAU. The sensor showed 106 -fold increased detection of H4N6 virus in blood in comparison to its commercial ELISA kit counterpart. The developed immunosensor may effectively change the way avian influenza is detected, monitored, and controlled;​ transforming timeconsuming reactive methods, into rapid predictive technology.