Electrical Characterization of a Thiol SAM on Gold as a First Step for the Fabrication of Immunosensors based on a Quartz Crystal Microbalance

Abstract

Abstract:In order to develop a robust biosensor based on quartz crystal microbalance technique for antigen detection, a control of the steps of the surface functionalization has been performed by impedance spectroscopy. The gold electrode is functionalized with the self-assembled monolayer technique. The high insulating properties of the acidic thiol monolayer has been characterized with cyclic voltammetry and impedance spectroscopy. The modified surface is activated with N-hydroxysuccinimide(NHS) and 1-(3-(dimethylamino)propyl)-3-ethylcarbodimide hydrochloride(EDC) cross-linker for antibody coupling. The non-specific sites are blocked with bovin serum albumine molecules. Different concentrations of antigen can be detected with a good reversibility in real time with the quartz crystal microbalance.

The biodistribution and pharmacokinetic evaluation of choline-bound gold nanoparticles in a human prostate tumor xenograft model

“…is is assigned functionalized GNPs (mean diameter = 27.3 nm, polydispersity index to the vibration mode of alkyl thiol chains. Bands at 1125-1335 cm -1 are assigned to the N-C stretch [31]. ese results con rm the presence of covalent thiol and amine bonds found in our PEI stabilized choline-GNPs.…”

A Simple Route to Asymmetric Composite Particles via Co-assembly of Block Copolymer and Inorganic Nanoparticles in Solution

“…[7] The presence of the large band in the range of 500 to 750 cm -1 illustrates the formation of a covalent gold-sulfur bond. [8] The ESD result (Fig.2B) also shows that the particle contained Fe, O, C and S elements. Fig.…”

Preparation and Characterization of Imunosensors for Disease Diagnosis

“…It is easy to denote the presence of the SAM, for instance, on gold electrode since it can be oxidized to form gold oxides which are reduced to metallic gold again. A fresh gold electrode was evaluated before and after thiol deposition by means of a triangular potential scanning (Tlili et al, 2004) and it was observed that the oxidation reaction was reduced and no cathodic current peak was observed after the SAM formation of thiol. The stability of oquinone produced on glassy carbon electrode modified with single-walled carbon nanotubes was confirmed by CV (Panini et al, 2008).…”

“…The magnetic force was useful to enhance the response of the sensor. Many other studies were developed using the QMC technique to confirm the deposition of biological molecules on self-assembled superstructures and immunosensor assay (Shen et al, 2001;Calvo et al, 2004;Tlili et al, 2004;Mutlu et al, 2008;Boujday et al, 2009). A deep discussion on the use of QMC technique on the step-by-step immunosensor characterization and on immunosensor assay can be found in another specific chapter in this book.…”