Adsorption Kinetics of Glutathione Monolayers on Platinum and Gold Surfaces used for Ca2+ Sensor Development

• Main Authors: Ferdaous MAATOUK, Houcine BARHOUMI, Abderrazak MAAREF, Nicole JAFFREZIC-RENAULT
• Format: Article
• Language: English
• Published: IFSA Publishing, S.L. 2014-05-01
• Series: Sensors & Transducers
• Subjects: Gold and Platinum Surfaces; SAM-Glutathione; Impedance Spectroscopy; Calcium Sensor.
• Online Access: http://www.sensorsportal.com/HTML/DIGEST/may_2014/Special_issue/P_SI_475.pdf

This work investigates the electrochemical study of glutathione self-assembled monolayers (SAMs) prepared from aqueous solution on gold and platinum surfaces. The deposit SAMs monolayers were characterized by cyclic voltammetry and electrochemical impedance spectroscopy methods. In addition, the interpretation of electrochemical impedance spectroscopy results was based on the charge-transfer reaction using potassium hexacyanoferrate (II/III) as redox-active probe. The structure and the properties of the deposit monolayers on the metal surfaces were obtained under optimal experimental conditions. It was shown that the adsorption kinetics is also influenced by some parameters such as the metal nature, the temperature, the pH and the immersion time in the thiol solution. The developed self-assembled monolayer (SAM-Glutathione) on the gold surface was applied to the detection of calcium ions. As a result, a stable and reproducible calcium sensor was obtained with a sensitivity of 58.4 KW/pCa in the linear range from 10-4 M to 10-1 M. A detection limit around 10-4 M for Ca2+ ions was obtained.