Diamine oxidase-modified screen-printed electrode for the redox-mediated determination of histamine

Histamine is an important biogenic amine because of its role in immune responses and the regulation of physiological functions. It is also used as a food freshness indicator, so its maximum concentration in fish is legally regulated. Although several robust and sensitive methods for histamine detection are already available, it continues to be a challenge to develop simple and portable devices that allow rapid histamine screening at any point of the fish production chain. Thus, in this work, a simple, miniaturized and low-cost sensor for histamine analysis was developed. The construction of the sensor only takes 30 min and consists of the immobilization of the enzyme diamine oxidase on the surface of a screen-printed carbon electrode by cross-linking. The quantification of histamine was achieved by chronoamperometry (+ 0.2V,120 s) using hexacyanoferrate (III) as a redox mediator. This selective sensor provided a low limit of detection (0.97 mg L−1) and accurate and precise results and was successfully applied to the analysis of spiked tuna and mackerel extracts,obtaining recovery values of 99–100%. Moreover, the sensor shows good stability, maintaining 87.7% of its initial signalafter 35 days.This work was supported by UID/QUI/50006/2019 with funding from the Fundação para a Ciência e a Tecnologia (FCT)/the Ministério da Ciência, Tecnologia e Ensino Superior (MCTES) through national funds. The authors also thank FCT and the EU for funding through the projects: FOODnanoHEALTH - Qualidade e Segurança Alimentar –uma abordagem (nano)tecnológica (Portugal2020, Norte-01-0145-FEDER-000011), FishBioSensing - Portable electrochemical (bio)sensing devices for safety and quality assessment of fishery products (02/SAICT/2016, POCI-01-0145-FEDER-023817), PTDC/ASP-PES/29547/2017 –CECs(Bio)Sensing - (Bio)sensors for assessment of contaminants of emerging concern in fishery commodities, (POCI-01-0145-FEDER-029547) and PTDC/QUI-QAN/30735/2017 –TracAllerSens - Electrochemical sensors for the detection and quantification of trace amounts of allergens in food products (POCI-01-0145-FEDER-030735), supported by national funds by FCT / MCTES and co-supported by Fundo Europeu de esenvolvimento Regional (FEDER) through COMPETE 2020 –Programa Operacional Competitividade e Internacionalização. E. Costa-Rama thanks the Government of Principado de Asturias and Marie Curie-Cofund Actions for the post-doctoral grant “Clarín-Cofund”ACA17-20. R. Torre is grateful for her PhD grant from FCT (SFRH/BD/143753/2019), fi- nanced by POPH–QREN–Tipologia 4.1–Formação Avançada, and subsidized by FSE and MCTES