Biosensor for the oxidative stress biomarker glutathione based on SAM of cobalt phthalocyanine on a thioctic acid modified gold electrode

Abstract : Self-assembled monolayer (SAM) of cobalt teraaminophthalocyanine (CoTAPc) was developed on thioctic acid (TA) dithiol modified gold electrode and electrochemically evaluated as a glutathione (GSH) selective biosensor. The CoTAPc-TA-Au modified electrode was developed by the covalent immobilization of the CoTAPc as the electrochemical mediator onto previously prepared gold electrode modified with TA (TA-Au) via amid bond formation with the carboxylic group of TA, producing well-organized SAM of the mediator. For comparison, another electrode modified with 3-mercaptopropionic acid (MPA) as a monothiol linker instead of TA was similarly prepared. The electrode surface modification was characterized using SEM, AFM, CV, and EIS. The contact angle measurements of the surface confirmed the formation of CoTAPc SAM on both TA and MPA modified electrodes. The CoTAPc-TA-Au modified electrode showed enhanced catalytic activity for GSH oxidation compared to that of CoTAPc-MPA-Au, indicating that the TA dithiol allowed for more coverage of the catalyst layer on the electrode surface with stronger binding. The experimental parameters controlling the voltammetric processes like scan rate and pH of sample solution were optimized. Using DPV technique, the proposed sensor exhibited a linear response of oxidation peak current vs. GSH concentration, over the concentration range between 10 and 100molL(-1) with a LOD of 1.5molL(-1) for the CoTAPc-TA-Au modified electrode compared to 5.5molL(-1) GSH, for the CoTAPc-MPA-Au electrode. The proposed sensor was utilized for detection of glutathione in some hemolyzed blood samples.
Document type :
Journal articles
Complete list of metadatas

https://hal.archives-ouvertes.fr/hal-02109076
Contributor : Agnès Bussy <>
Submitted on : Wednesday, April 24, 2019 - 3:41:29 PM
Last modification on : Thursday, April 25, 2019 - 1:28:54 AM

Identifiers

Collections

Citation

Mohammed Nooredeen Abbas, Ayman Ali Saeed, Mounir Ben Ali, Abdelhamid Errachid, Nadia Zine, et al.. Biosensor for the oxidative stress biomarker glutathione based on SAM of cobalt phthalocyanine on a thioctic acid modified gold electrode. Journal of Solid State Electrochemistry, Springer Verlag, 2019, 23 (4), pp.1129-1144. ⟨10.1007/s10008-018-04191-4⟩. ⟨hal-02109076⟩

Share

Metrics

Record views

11