A Voltammetric Nanodiamond-Coated Screen-Printed Immunosensor for The Determination of a Peanut Allergen in Commercial Food Products

Abstract

A voltammetric immunosensor was developed to quantify a major peanut allergen, Ara h 1, using screen-printed carbon electrodes (SPCE) as transducers. A sandwich-type immunoassay was performed on nanodiamond-coated SPCEs using an alkaline phosphatase-labeled detection antibody and a mixture containing an enzymatic substrate (3-indoxyl phosphate) and silver nitrate. The immunological interaction was detected through the (linear sweep) voltammetric stripping of the enzymatically deposited silver. The immunosensor’s applicability was evaluated by analyzing breakfast cereals, cookies, and energy and cereal bars. Ara h 1 was successfully tracked in these commercial food products.