A Novel Amperometric Immunosensor for Phytohormone Abscisic Acid Based on In Situ Chemical Reductive Growth of Gold Nanoparticles on Glassy Carbon Electrode

An amperometric immunosensor for phytohormone abscisic acid was developed based on in situ chemical reductive growth of gold nanoparticles on glassy carbon electrode. First, an approximate 10nm gold layer was sputtered uniformly onto the electrode surface, and then gold nanoparticles were grown directly on the gold layer for antibody adsorption by immersing the electrode into the H2AuCl4 solution. Determination was based on an enzyme-linked competitive immunoreaction between free and enzyme-labeled abscisic acid to bind on immobilized antibody on electrode. The linear response was from 10ng/ml to 10 mu g/ml with a detection limit of 5ng/ml.