Modified gold surfaces by 6-(ferrocenyl)hexanethiol/dendrimer/gold nanoparticles as a platform for the mediated biosensing applications

• DOI: 10.1016/j.msec.2012.10.008
• Publication Date: 2012-11-02T19:30:44Z
• Authors: Murat Karadag; Caner Geyik; Dilek Odaci Demirkol; F. Nil Ertas; Suna Timur
• Keywords: Self assembled monolayers; Blood Glucose; Dendrimers; Metal Nanoparticles; Biosensing Techniques; Enzymes, Immobilized; Microscopy, Atomic Force; 01 natural sciences; Glucose biosensor; 0104 chemical sciences; Beverages; Glucose Oxidase; Glucose; Limit of Detection; Gold nanopArticles; Humans; Ferrous Compounds; Gold

An electrochemical biosensor mediated by using 6-(Ferrocenyl) hexanethiol (FcSH) was fabricated by construction of gold nanoparticles (AuNPs) on the surface of polyamidoamine dendrimer (PAMAM) modified gold electrode. Glucose oxidase (GOx) was used as a model enzyme and was immobilized onto the gold surface forming a self assembled monolayer via FcSH and cysteamine. Cyclic voltammetry and amperometry were used for the characterization of electrochemical response towards glucose substrate. Following the optimization of medium pH, enzyme loading, AuNP and FcSH amount, the linear range for the glucose was studied and found as 1.0 to 5.0mM with the detection limit (LOD) of 0.6mM according to S/N=3. Finally, the proposed Au/AuNP/(FcSH+Cyst)/PAMAM/GOx biosensor was successfully applied for the glucose analysis in beverages, and the results were compared with those obtained by HPLC.