An enzyme-free electrochemical method for the determination of E-coli using Fe3O4 nanocomposites with a SiO2 shell modified by ferrocene

作者：Kozitsina A N^*; Malysheva N N; Utepova I A; Glazyrina Yu A; Matern A I; Brainina Kh Z; Chupakhin O N

来源：Journal of Analytical Chemistry, 2015, 70(5): 540-545.

DOI：10.1134/S1061934815050068

• cyclic voltammetry
• immunoassay
• electroactive nanocomposite particles

An electrochemical immunoassay method is developed for determining the strain of Escherichia coli ATCC 25922 with the use of electroactive nanocomposite particles based on magnetite Fe3O4 coated by SiO2 modified with ferrocene as a signal label. A sensitive, direct, and easily measured analytical response is obtained by cyclic voltammetry. The developed method enables the determination of bacterial cells at a minimum concentration of 2.3 x 10(3) CFU/mL. The analytical range is 2.3 x 10(3)-2.3 x 10(7) CFU/mL; the detection limit is 2.5 x 10(2) CFU/mL. The required sample volume is 0.5 mL, and the analysis time is 40 min.

• 出版日期2015-5