Hierarchical flower-like zinc oxide nanosheets in-situ growth on three-dimensional ferrocene-functionalized graphene framework for sensitive determination of epinephrine and its oxidation derivative

Epinephrine (EP) is a significant neurotransmitter, energizes and maintains the various body systems and plays a pivotal role in the response to stressful conditions of blood pressure and blood sugar level. Herein, a novel epinephrine sensor based on the hierarchical flower-like zinc oxide nanosheets (flower-like ZnO) embedded into three-dimensional ferrocene-functionalized graphene framework (3D graphene@Fc) was successfully prepared, using a facile route of one-pot in situ hydrothermal growth method. Benefiting from the unique structural advantages, meanwhile integrated with synergistic effect of components, the flower-like ZnO/3D graphene@Fc exhibits excellent sensing performance for epinephrine with a wide linear range of 0.02 to 216 mu M, a low detection limit of 0.0093 mu M, high anti-interference and good cyclic stability. Interestingly, it is unexpectedly found that the flower-like ZnO/3D graphene@Fc has sensing ability for EP's oxidized derivative (QA) during the oxidation process of EP, along with a linear range of 0.192 to 527 mu M and a detection limit of 0.1 mu M for QA. More importantly, acceptable recovery obtained from the real sample test, confirming the feasibility of this biosensor for practical application.