title: Competitive immunosensor based on gliadin immobilization on disposable carbon-nanogold screen-printed electrodes for rapid determination of celiotoxic prolamins.
abstract: The first competitive disposable amperometric immunosensor based on gliadin-functionalized carbon/nanogold screen-printed electrodes was developed for rapid determination of celiotoxic prolamins. To date, no competitive spectrophotometric or electrochemical immunoassays have yet been successfully applied to gluten detection in processed food samples, which require the use of complex prolamin extraction solutions containing additives with denaturing, reducing and disaggregating functions. Thus, in this work, great effort was put into the optimization and performance evaluation of the immunosensor in terms of suitability as a screening tool for analysis of cereal-based food samples. For this purpose, aqueous ethanol or complex extraction mixtures, as the patented Cocktail Solution®, were proved effective in the extraction of gliadin. Good sensitivity was achieved after optimization of the immunocompetitive assay, giving limit of detection and limit of quantitation of 8 and 22 ng/ml of gliadin, respectively, for ethanol extracts. The immunosensor was proved to be suitable also for samples extracted with Cocktail Solution® after a proper dilution. Analysis of real samples of different flours proved the suitability of the immunosensing device as a powerful tool for safety assessment of raw materials used for the formulation of dietary products for celiac disease patients. This immunosensor combines good analytical performance using a very simplified set-up protocol with suitability for rapid screening analysis performed using inexpensive and portable instrumentation. Graphical abstract Depiction of the development and working principle of the competitive immunosensor.
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Parma, Parco Area delle Scienze 17/A, 43124, Parma, Italy.
authors.forename: Anita
authors.initials: A
authors.lastname: Manfredi
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Parma, Parco Area delle Scienze 17/A, 43124, Parma, Italy. marco.giannetto@unipr.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Giannetto
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Parma, Parco Area delle Scienze 17/A, 43124, Parma, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Mattarozzi
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Parma, Parco Area delle Scienze 17/A, 43124, Parma, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Costantini
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Parma, Parco Area delle Scienze 17/A, 43124, Parma, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Mucchino
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Parma, Parco Area delle Scienze 17/A, 43124, Parma, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Careri
mesh_terms: D015374:Biosensing Techniques / Q000191:economics / Q000295:instrumentation / Q000379:methods*; D002244:Carbon / Q000737:chemistry; D002446:Celiac Disease / Q000209:etiology / Q000517:prevention & control; D002523:Edible Grain / Q000737:chemistry*; D004566:Electrodes; D004867:Equipment Design; D005504:Food Analysis / Q000191:economics / Q000295:instrumentation / Q000379:methods*; D005903:Gliadin / Q000032:analysis* / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D006801:Humans; D055767:Immobilized Proteins / Q000032:analysis / Q000737:chemistry; D007118:Immunoassay / Q000191:economics / Q000295:instrumentation / Q000379:methods; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry
chemical_list: D055767:Immobilized Proteins; D002244:Carbon; D006046:Gold; D005903:Gliadin
keywords: Celiac disease; Cocktail solution; Competitive immunosensor; Food safety; Gluten