Novel electrochemical immunosensing platform based on magnetite-antibody conjugate as a direct signal label: design and application for Salmonella typhimurium antigen determination

Abstract

A novel electrochemical sensing platform based on Fe₃O₄-antibody conjugate was developed for the rapid and sensitive determination of Salmonella typhimurium antigen in model suspensions. The conjugates Fe₃O₄-antibody were synthesized via carbodiimide cross-linking and characterized by infrared spectroscopy and cyclic voltammetry. The electrochemical properties of Fe₃O₄ magnetic nanoparticles in water were investigated; the possible mechanism of direct electrochemical reduction was proposed and justified as an analytical signal. The design of an electrochemical sensing platform with magnetically controlled flows has been proposed. Under the most appropriate conditions, the developed portable device was provided the linear response as I (µA) = (7.20 ± 0.35) × (–lg C_Ag) − (23.77 ± 1.95) in the concentration range 1 × 10⁻⁷–1 × 10⁻⁴mg/mL. The detection limit was 390 ng/mL and was comparable to other works.

Keywords:

• Bacteria antigen determination
• cyclic voltammetry (CV)
• differential pulse voltammetry (DPV)
• electrochemical immunosensor
• Salmonella typhimurium

View correction statement:

Correction

Disclosure statement

The authors report there are no competing interests to declare.

Additional information

Funding

The research was supported by the Council for Grants of the President of the Russian Federation under Grant MK-392.2022.1.3 and the Ministry of Science and Higher Education of the Russian Federation (Ural Federal University project within the Priority-2030 Program.