CoCr2O4/Graphene modified glass carbon electrode for highly dual-sensing detection of hydrogen peroxide and glucose

The development of a non-enzymatic electrochemical sensor possessing well dual-sensing to H 2 O 2 and glucose remains challenging due to less report. Herein, spinel CoCr 2 O 4 nanoparticles with small size were synthesized by sol–gel reaction, which were then simply mixed with commercial graphene under ultrasonic to obtain uniformly dispersed CoCr 2 O 4 /Graphene composite. They were deposited onto the surface of bare glassy carbon electrode (GCE) through a common drop-coating method. The CoCr 2 O 4 /Graphene/GCE sensor firstly achieves highly dual-sensing to H 2 O 2 and glucose in 0.1 M NaOH solution. At 0.4 and 0.55 V, its sensitivities to H 2 O 2 and glucose can separately reach up to 1168.6 and 1722.5 μA mM −1 cm −2 , and the corresponding detection limits are as low as 18 nM and 12 nM. These key indexes are the best among reported dual-functional spinel oxide-based electrodes. This excellent electrochemical sensing ability stems from its large electrode active area, good conductivity, and the synergism between graphene and CoCr 2 O 4 nanoparticles with mixed redox couplings, which provides an efficient platform for dual-sensing detection. In addition, the modified electrode can accurately determine glucose in human tears, rat serum and orange juice, as well as H 2 O 2 in milk whey, mouthwash and disinfectant, thus predicting its good application prospects.