Controllable design of polycrystalline synergies: Hybrid FeO_x nanoparticles applicable to electrochemical sensing antineoplastic drug in mammalian cells

摘要

Investigations on interplay between sensing platform performance and crystal phase of material are the new beginning of designing advanced bioanalytical systems. Herein, FeOxnanoparticles (NPs, ∼100 nm), including superfine magnetic (Fe3O4) and hematite (α-Fe2O3) nanocrystals in single particles, have been employed to verify the synergistic effect between the electrocatalytic property and the polycrystalline structure of the materials. Moreover, this strategy overcomes that single crystal phases generally suffer from serious agglomeration and poor electrical conductivity. More importantly, hybrid metal oxides (e.g., α-Fe2O3/Fe3O4) with variable oxidation states remarkably facilitate the efficient redox charge transfer. Taking the detection of Flutamide (FLT) in prostate cancer cells (VCaP cells) as example, the dynamic ranges of the oxidation states from the different crystal phases were integrated into a single electrochemical sensor interface. Furthermore, good selectivity, accuracy, satisfactory sensitivity (769.1 μA mM−1 cm-2) and low detection limits (46.6 nM) were achieved. Going beyond the conventional single-crystal phase-driven electrochemical sensing, the elaborate of polycrystalline structure in a single particle may open a new approach for the design of outstanding electrode materials, which not only can significantly improve the performance of sensing platforms, but also can be used to rationally design the material properties according to the applications.