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

Abstract

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 10 nm 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 10 ng/ml to 10 µg/ml with a detection limit of 5 ng/ml.

Keywords:

• Abscisic acid (ABA)
• gold nanoparticles
• immunoreaction
• in situ chemical reduction

This work was supported by the National Natural Science Foundation of China (Grant Nos. 90817101, 30670190 and 30600049) and the National Commonwealth Research Project of China for Quality Supervision, Inspection and Quarantine (Grant No. 2007GYB146).