Application of a printed silver-based electrocatalyst for H2O2 reduction to the determination of cholesterol

Gonzalez-Macia, Laura; Killard, Anthony

Abstract

Many current clinical disorders such as hypertension, arteriosclerosis, coronary artery disease and cerebral thrombosis are associated with abnormal levels of cholesterol in blood. Therefore, the development of a reliable and simple method for cholesterol determination is essential in clinical diagnosis.

Electrochemical biosensors have been shown to be a very important method of cholesterol estimation because they provide rapid responses without the need of sample dilution and they are suitable for mass production at low cost. Cholesterol oxidase (ChOx) is most commonly used as the biosensing element in the fabrication of cholesterol biosensors. Hydrogen peroxide (H2O2) is released as the end-product of the enzymatic reaction and its concentration may be used as an indicator in the progress of the reaction.

Recently, our group has reported a significant enhancement in the catalytic activity of silver screen printed electrodes (Ag SPEs) towards H2O2 reduction after exposure to a mixed surfactant/salt solution.[1] The electrodes modified with a dodecylbenzenesulphonic acid (DBSA) and KCl solution exhibited up to 80-fold higher responses when H2O2 was measured by amperometry at -0.1 V vs. Ag/AgCl.

In the present work, DBSA/KCl modified Ag SPEs were used as a platform for the development of a cholesterol biosensor by coupling its electrocatalytic ability towards H2O2 reduction to the enzymatic oxidation of the cholesterol by cholesterol oxidase. The use of inkjet printing during the modification process might improve the variability of the sensing devices found in previous manual modification procedures by enhancing the control of the reagent volume and exposure times.[2] Also, it would allow the deposition of low volume of the biological reagents, leading to a reduction of the waste. Analytical parameters of the biosensors such as LOD, sensitivity and reproducibility were measured. The device was then assessed for the quantitative determination of cholesterol in serum.

• Presentation Conference Type: Presentation / Talk
• Conference Name: 3rd International Conference on Bio-Sensing Technology 2013
• Start Date: May 12, 2013
• End Date: May 15, 2013
• Publication Date: May 1, 2013
• Peer Reviewed: Peer Reviewed
• Keywords: electrocatalysis, hydrogen peroxide, cholesterol, biosensor
• Public URL: https://uwe-repository.worktribe.com/output/932359
• Additional Information: Title of Conference or Conference Proceedings : 3rd International Conference on Bio-Sensing Technology