Bifunctional (Zn,Fe)3O4 nanoparticles: Tuning their efficiency for potential application in reagentless glucose biosensors and magnetic hyperthermia.

Abstract In a new approach based on a two-step procedure, co-precipitation method followed by hydrothermal treatment in a microwave field, Zn-substituted Fe 3 O 4 nanoparticles (Zn x Fe 3- x O 4) were synthesized. Results of XRD, FT–IR and TEM analysis clearly demonstrate that nanoparticles were single phase, crystallizing in the spinel structure type (S.G. Fd 3 ¯ m) with crystallite size in the range of 2–20 nm, which strongly depends on Zn concentration. The produced nanoparticles were used for fabrication of modified carbon paste electrodes as a novel system for electrochemical non-enzymatic glucose detection. It was found that the increase of zinc concentration up to the value of x = 0.56 (Zn 0.56 Fe 2.44 O 4) of as-prepared nanoparticles was followed with an increase of a performance of the modified carbon paste electrode toward glucose detection. Linear working range from 0.1 to 2 mM was obtained with detection limit of 0.03 mM, and with fast response time (<3 s). Proposed sensor was successfully applied for the determination of glucose level in real samples with satisfactory recovery. The synthesized zinc-ferrite samples were also tested as potential heating agents in magnetic hyperthermia. The heating ability (SAR value) increases with x value, reaching maximum for x = 0.37. This is correlated with changes of particle size and magnetic characteristics which strongly depend on Zn concentration. Highlights • Preparation of Zn x Fe 3- x O 4 composite by co-precipitation method in combination with hydrothermal treatment. • Effect of zinc content in ferrite structure was investigated and bifunctionality of the material was shown. • Construction of non-enzymatic glucose biosensor based on substituted magnetite was done. • Promising sensitivity, satisfactory selectivity and simplicity of glucose detection were achieved. • Prepared materials were tested as potential heating agents in magnetic hyperthermia. [ABSTRACT FROM AUTHOR]