An Amperometric Immunosensor Based on a Polyelectrolyte/Nano Gold Particle Layer-by-Layer Assembly Modified Electrode for the Determination of Clenbuterol in Meat

This paper introduces a novel amperometric immunosensor consisting of hemin (Fe(III)-protoporphyrinIX) layers formed by layer-by-layer assembly for determination of clenbuterol (CLB). Layer-by-layer assembly of hemin with Poly(allylamine hydrochloride) (PAH) is achieved on the electrode surface which is modified by single-wall carbon nanotubes (SWCNTs) based on the electrostatic attraction between negatively charged hemin and positively charged Poly(allylamine hydrochl- oride). The modified electrodes were characterized by cyclic voltammetry (CV), scanning electron microscope (SEM), and X-ray photo electron spectrum (XPS). The decrease of current results from the increasing concentration of CLB antigen, which leads to a linear decrease in CLB antigen concentration ranges from 0.5 ~ 10 ng/mL with the detection limit of 0.2 ng/mL (3σ).