A Simple and Sensitive Electrochemical Sandwich-Like Immunosensor for Interleukin-8 Utilizing Carbon Black as a Sensing Platform and Silver-Ferrocene as a Signal Amplifier

Designing sensitive and low-cost method for interleukin-8 (IL-8) determination is of great significance in the early diagnosis of oral cancer. In the present work, a simple, low-cost and sensitive sandwich-like electrochemical immunosensor of IL-8 was developed by introducing perylene tetracarboxylic acid-carbon black (PTCA-CB) as sensing platform and silver-ferrocene (Ag-Fc) as signal amplifier. PTCA-CB can offer large surface area and high conductivity as well as the stable supporter to assemble primary antibody (Ab(1)), while Ag could carry Fc probe and secondary antibodies (Ab(2)) to produce Ab(2)-Ag-Fc signal amplifier. In the presence of IL-8 with different concentrations, the peak currents from the formed sandwich-like structure Ab(2)-Ag-Fc/IL-8/Ab(1)/CB can increase with the increase of IL-8 concentration, a sensitive and low-cost electrochemical immunosensor for IL-8 was thus constructed based on this principle. After optimizing the related control conditions, a wide linear range (3.0 pg mL(-1) to 2.0 ng mL(-1)) and very low detection limit (1.0 pg mL(-1)) were achieved, it's thus convinced the developed sensor has important clinical applications.