Co3O4 and CuBi2O4 Hybrid Nanostructures for Efficient Nonenzymatic Glucose Detection in Human Blood and Serum Samples with Mechanistic Insights

Abstract In this report, CuBi 2 O 4 /Co 3 O 4 has been used for the electrochemical detection of glucose. Herein, CuBi 2 O 4 nanorods and Co 3 O 4 has been hybridized with CuBi 2 O 4 to form CuBi 2 O 4 /Co 3 O 4 nanocomposite hydrothermally. CuBi 2 O 4 and CuBi 2 O 4 /Co 3 O 4 electrodes are fabricated by using drop casting method. Structural, morphological studies of CuBi 2 O 4 /Co 3 O 4 and electrochemical characterizations pertaining to its performance in comparison to CuBi 2 O 4 for electrochemical detection of glucose are performed and discussed elaborately. The detailed mechanism involved in the electrochemical detection of glucose is proposed. The electrode has shown the sensitivity of 49 μA mM −1 cm −2 with a limit of detection (LOD) of 0.136 μM. DFT calculations are performed on the optimized molecules involved in the electrochemical detection of glucose confirming CuBi 2 O 4 /Co 3 O 4 acting as electron donor while glucose as electron acceptor. Further, natural bond orbital (NBO) for charge distribution calculations and ESP mappings for the optimized molecules are performed to understand nucleophilic/electrophilic positions. This study reveals that CuBi 2 O 4 and its modifications are promising materials for the electrochemical detection of glucose. Further, the role of Co 3 O 4 in improving the sensitivity and electrochemical performance for detection of glucose has been discussed.