Detection of the peanut allergen Ara h 6 in foodstuffs using a voltammetric biosensing approach

A voltammetric biosensor for Ara h 6 (a peanut allergen) detection in food samples was developed. Gold nanoparticle-modified screen-printed carbon electrodes were used to develop a sandwich-type immunoassay using two-monoclonal antibodies. The antibody-antigen interaction was detected through the electrochemical detection of enzymatically deposited silver. The immunosensor presented a linear range between 1 and 100 ng/ml, as well as high precision (inter-day RSD ≤9.8 %) and accuracy (recoveries ≥96.7 %). The detection and quantification limits were 0.27 and 0.88 ng/ml, respectively. It was possible to detect small levels of Ara h 6 in complex food matrices

Development of amperometric enzyme electrodes in reversed micelles media

The suitability of reversed micelle systems as working media for the development of amperometric enzyme electrodes is discussed from an electroanalytical point of view

Electrochemical methods to characterize nanomaterial-based transducers for the development of noninvasive glucose sensors

Electrochemical biosensors consist of electrodes modified with nanomaterials that contain immobilized biomolecules for analyte recognition and utilize electrochemical transduction; a glucose meter is an example of such a biosensor. Innovation in glucose monitoring includes non-invasive sensing, where alternative body fluids such as saliva can be used in place of blood, eliminating finger-pricking. However, the concentration of glucose in saliva is twofold lower than in blood, demanding a more sensitive transducer. For a decade, research focused on enhancing the transduction layer by modifying electrodes with nanomaterials that can increase electron transfer, enabling detection of glucose at much lower concentrations. The contribution of these nanomaterials towards enhancement of electron transfer can be understood via electrochemical characterization techniques such as cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrical impedance spectroscopy (EIS). This chapter provides the basis of the voltammetry techniques and EIS with example graphs from our current research. The aforementioned techniques were performed on screen-printed glassy carbon electrodes modified with reduced graphene–conductive polymer composites, with voltammetry measurements providing CV and LSV and EIS measurements, with EIS resulting in Bode and Nyquist plots and Randles equivalent circuit. Results from our study show a reversible electrode reaction that is diffusion controlled