Browsing by Author "Torre, Ricarda"
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- Amperometric enzyme sensor for the rapid determination of histaminePublication . Torre, Ricarda; Costa Rama, Estefanía; LOPES, Paula; Nouws, Henri; Delerue-Matos, CristinaThe concentration of histamine, a biogenic amine, in fish is considered a fish spoilage indicator. Therefore, the development of a rapid-response and portable tool that allows its on-site analysis is very interesting since the consumption of high amounts of histamine causes scombroid poisoning. Thus, in this work a simple enzymatic sensor for the determination of histamine, based on a screen-printed carbon electrode and the enzyme diamine oxidase, was developed. The enzyme was immobilized on the electrode surface through a simple cross-linking procedure employing glutaraldehyde and bovine serum albumin. Chronoamperometry was used as the detection technique; the sensor showed a short response time (60 s, -0.3 V) and the measurements were performed by only using 40 μL of sample solution. The sensor provides an useful linear range (between 1 and 75 mg L-1 in fish extract), excellent reproducibility (RSD = 2.6%) and is reusable for up to 7 measurements. The feasibility of the sensor was tested performing histamine analysis in fish extracts achieving recovery values of 103%.
- Diamine oxidase-modified screen-printed electrode for the redox-mediated determination of histaminePublication . Torre, Ricarda; Costa Rama, Estefanía; Nouws, Henri; Delerue-Matos, CristinaHistamine 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.
- Food allergen control: Tropomyosin analysis through electrochemical immunosensingPublication . Torre, Ricarda; Freitas, Maria; Costa‐Rama, Estefanía; Nouws, Henri; Delerue-Matos, CristinaRegulations of the EU obliges the indication of the presence of allergens on food labels. This work reports the development of an electrochemical immunosensor to determine tropomyosin (TPM) – a major shellfish allergen – prevailing in the muscles of crustacean species. Two linear ranges between the signal and TPM concentration were obtained: between 2.5 and 20 ng mL−1 and between 30 and 200 ng mL−1, with a lowest limit of detection of 0.47 ng mL−1. The selectivity of the optimized immunoassay, tested with other food allergens (e.g., Cyp c 1, a fish allergen), assures the effective detection of TPM, enabling successful control of foodstuff labelling. Several (12) foods, containing high and low TPM concentrations and TPM-free samples, were analysed using the sensor. A conventional ELISA kit and recovery assays were used to evaluate the accuracy of the results.
- Screen-Printed Electrode-Based Sensors for Food Spoilage Control: Bacteria and Biogenic Amines DetectionPublication . Torre, Ricarda; Costa-Rama, Estefanía; Nouws, Henri P. A.; Delerue-Matos, CristinaFood spoilage is caused by the development of microorganisms, biogenic amines, and other harmful substances, which, when consumed, can lead to different health problems. Foodborne diseases can be avoided by assessing the safety and freshness of food along the production and supply chains. The routine methods for food analysis usually involve long analysis times and complex instrumentation and are performed in centralized laboratories. In this context, sensors based on screen-printed electrodes (SPEs) have gained increasing importance because of their advantageous characteristics, such as ease of use and portability, which allow fast analysis in point-of-need scenarios. This review provides a comprehensive overview of SPE-based sensors for the evaluation of food safety and freshness, focusing on the determination of bacteria and biogenic amines. After discussing the characteristics of SPEs as transducers, the main bacteria, and biogenic amines responsible for important and common foodborne diseases are described. Then, SPE-based sensors for the analysis of these bacteria and biogenic amines in food samples are discussed, comparing several parameters, such as limit of detection, analysis time, and sample type.