Electrochemical biosensors for biogenic amines: a comparison between different approaches

Potentiometric sensing of histamine using immobilized enzymes on layered double hydroxides

Diamine oxydase and peroxidase have been co-immobilized onto layered double hydroxide (LDH) thin films for the development of real-time histamine biosensors. The chosen LDH materials are Mg₂AlCO₃, Mg₄FeCl and Ca₂AlCl. Prepared bi-enzymatic hybrid nanomaterials are capable of detecting histamine through the electrochemical oxidation of H₂O₂ and are used as the sensitive membrane for potentiometric microelectrode. Histamine biosensors developed in this work have fast response of less than 20 s, are sensitive and selective, with a large dynamic range of 10^-8-10^-3 M and a limit of detection of less than 10^-8 M. The detection limit of the developed bi-enzymatic biosensors is relatively higher than those corresponding with gas and liquid chromatography, which are still considered as the reference methods. Finally, the reproducibility, the specificity and the storage stability of the biosensors were studied.

A review on chemical and electrochemical methodologies for the sensing of biogenic amines

Biogenic amines (BA) are biomolecules of low molecular weight with organic basic functionalities (amine group) that are formed by the microbial decarboxylation of amino acids of fermented food/beverages. Hence BAs are an important indicator in estimating the freshness and quality of meat, seafood, and industrial food products with high protein content. The reaction of BAs with nitrites available in certain meat products forms nitrosoamine, a carcinogenic compound. Hence BAs are in general considered to be a food hazard and monitoring the level of BAs in food samples becomes crucial as their high concentrations may lead to health problems. This review offers an overview of the available chemical and electrochemical methods that are typically used for the sensing of BAs in food samples. Certain compounds are known to selectively interact with BAs via chemical or non-covalent interactions and these interactions are often accompanied by fluorescence or visible color changes (sometimes visual detection) that could be monitored/assessed using a fluorescence spectrophotometer or UV-vis spectrophotometer (colorimetric methods). The colorimetric methods are limited by sensitivity and selectivity as they are based on straight-forward chemical reactions. In the case of electrochemical sensing of BAs, mediators are often used which undergo oxidation/reduction to produce intermediates that could interact with BAs accompanied by changes in their electrochemical potential. Overall, this review summarizes the available chemical and electrochemical strategies towards the sensing of BAs with a discussion on further prospects.

Biosensing the Histamine Producing Potential of Bacteria in Tuna

Histamine poisoning is the most common cause of human foodborne illness due to the consumption of fish products. An enzyme-based amperometric biosensor was developed to be used as a screening tool to detect histamine and histamine-producing bacteria (HPB) in tuna. It was developed by immobilizing histidine decarboxylase and horseradish peroxidase on the surface of screen-printed electrodes through a cross-linking procedure employing glutaraldehyde and bovine serum albumin. The signal generated in presence of histamine at the surface of the electrode was measured by chronoamperometry at in presence of a soluble redox mediator. The sensitivity of the electrode was 1.31-1.59 μA/mM, with a linear range from 2 to 20 μg/ml and detection limit of 0.11 μg/ml. In this study fresh tuna filets purchased in supermarkets in different days (n = 8) were analyzed to detect HPB. Samples with different concentration of histamine were analyzed with culture-based counting methods, biosensor and HPLC and also a challenge test was made. Recovery of histamine from cultures and tuna samples was also assessed. The presence of Morganella psychrotolerans, Photobacterium phosphoreum, P. damselae and Hafnia alvei was detected using culture- and PCR-based methods. At the time of purchase these tuna samples had histamine concentrations from below the limit of detection (LOD) to 60 μg/g. HPLC and biosensor methods provided similar results in the range from zero to 432 μg/g (correlation coefficient, R 2 = 0.990) and the recovery of histamine from cultures and tuna samples was very high (mean bias -12.69 to 1.63%, with root-mean-square error <12%). These results clearly show that fresh tuna is commonly contaminated with strong HPB. The histamine biosensor can be used by the Food Business Operators as a screening tool to detect their presence and to determine whether their process controls are adequate or not.

Detection and Characterization of Histamine-Producing Strains of Photobacterium damselae subsp. damselae Isolated from Mullets

Photobacterium damselae subsp. damselae (Pdd) is considered to be an emerging pathogen of marine fish and has also been implicated in cases of histamine food poisoning. In this study, eight strains isolated from mullets of the genera Mugil and Liza captured in the Ligurian Sea were characterized, and a method to detect histamine-producing Pdd from fish samples was developed. The histamine-producing potential of the strains was evaluated in culture media (TSB+) using a histamine biosensor. Subsequently, two strains were used to contaminate mackerel fillets (4 or 40 CFU/g), simulating a cross-contamination on the selling fish stalls. Sample homogenates were enriched in TSB+. The cultures were then inoculated on thiosulfate-citrate-bile salts-sucrose agar (TCBS) and the dark green colonies were cultured on Niven agar. The violet isolates were characterized using specific biochemical and PCR based tests. All Pdd strains were histamine producers, yielding concentration varying from 167 and 8977 µg/mL in TSB+ cultures incubated at 30 °C for 24 h. Pdd colonies were detected from the inoculated mackerel samples and their histidine decarboxylase gene was amplified using species-specific primer pairs designed for this study. The results indicate that mullets can be source of Pdd and the fish retailers needs to evaluate the risk posed by cross-contamination on the selling fish stalls.

Simultaneous determination of cadaverine and putrescine using a disposable monoamine oxidase based biosensor

The selective and simultaneous amperometric determination of putrescine (Put) and cadaverine (Cad) has been carried out using a novel design of screen-printed carbon electrode (SPCE) with two working electrodes connected in array mode. A mixture of 3% of tetrathiafulvalene (TTF), as mediator, and carbon ink was used for the construction of the screen-printed working electrode. The employment of different amounts of monoamine oxidase (MAO) enzyme on these modified TTF/SPCEs and the use of gold nanoparticles (AuNPs) allowed performing the simultaneous determination of both analytes. The amperometric detection has been performed by measuring the oxidation current of the mediator at a potential of+250 mV vs. screen-printed Ag/AgCl reference electrode. A linear response in the Cad concentration range from 19.6 till 107.1 µM and from 9.9 till 74.1 μM for Put was obtained at the MAO/AuNPs/TTF/SPCE biosensor. This device showed a capability of detection of 9.9 and 19.9±0.9 µM (n=4 α=β=0.05) and a precision of 4.9% and 10.3% in terms of relative standard deviation for Put and Cad, respectively. The developed biosensor was successfully applied to the simultaneous determination of Put and Cad in octopus samples.

Amperometric biosensor for the determination of histamine in fish samples

A bienzymatic biosensor employing diamine oxidase (DOx) and horseradish peroxidase (HRP) for the detection of histamine in fish samples has been developed and optimized in this work. These enzymes have been co-immobilized into a polysulfone/carbon nanotubes/ferrocene membrane by means of phase inversion technique onto screen-printed electrodes. The electrochemical measurements have been carried out in phosphate buffer solution at pH 8.0 in batch mode and low applied potential (-50 mV vs. Ag/AgCl, KCl 0.1 M) to minimize the interferences. Developed biosensor exhibits high sensitivity (1.9×10(7) nA(-1)), low limit of detection (1.7×10(-7) M), high storage stability and excellent reproducibility, obtaining a linear interval range from 3×10(-7) to 2×10(-5) M. Finally, applicability of the biosensor to the estimation of histamine content in different fish samples has been assessed; obtaining a good correlation between results obtained with the biosensor and those obtained with the reference method (ELISA) in case of sardines, mackerel and greater weever.

An interference free amperometric biosensor for the detection of biogenic amines in food products

In this work is reported the development and application of an amperometric biosensor for the determination of total biogenic amines content by using the commercial diamino oxidase (DAO from Porcine kidney E.C. 1.4.3.6) as the biocomponent, entrapped by glutaraldehyde onto an electrosynthesized bilayer film. In order to minimize both the fouling and the interference caused by the direct electrochemical oxidation of both the analytes (i.e., biogenic amines) and the common interferents usually present in food products the performances of Pt and Au electrodes and of several electroproduced anti-interferents mono- and bi-layer films were tested. In spite of a very low activity of the commercial DAO, the biosensor displayed a high response sensitivity in flow experiments, short response time, a good linear response and low detection limits. The excellent anti-interference characteristics allowed the use of the biosensor in screening analysis of food products.

A sequential injection analysis/chemiluminescent plant tissue-based biosensor system for the determination of diamine

In this paper, a new chemiluminescent plant tissue-based biosensor for diamine detection was presented by employing sequential injection analysis (SIA), which facilitates precise fluidic handling and lower consumption of sample and reagents. Pea-seedling tissue acted as the molecular recognition element and was packed in a mini-PTFE column and further incorporated in the SIA system. The analysis of diamines, such as putrescine and cadaverine, is based on an enzymatic conversion which takes place in the plant tissue column to produce hydrogen peroxide. The formed hydrogen peroxide was detected by a chemiluminescence reaction involving luminol and Co(2+). Under the optimal conditions, the linear calibration graphs were obtained within 0.2-80 microM (putrescine) and 0.5-100 microM (cadaverine). The detection limits of 0.03 and 0.06 microM were achieved for putrescine and cadaverine, respectively, along with the relative standard deviations of 2.14% and 3.08% (n=11) and a sampling frequency of 40 h(-1). The present biosensor has been used for the analysis of diamine in fish samples with an acceptable accuracy.

Amperometric biosensor based on horseradish peroxidase for biogenic amine determinations in biological samples

An amperometric biosensor for total biogenic amine determinations, using a carbon paste electrode modified with horseradish peroxidase (HRP) enzyme is described. The HRP immobilization on graphite was made using bovine serum albumin, carbodiimide and glutaraldehyde. The biosensor response was optimized using serotonin and it presented the best performance in 0.1 mol l(-1) phosphate buffer (pH=7.0) containing 10 micromol l(-1) of hydrogen peroxide. Under optimized operational conditions at -50 mV versus SCE, a linear response range from 40 to 470 ng ml(-1) was obtained. The detection limit was 17 ng ml(-1) and the response time was 0.5s. The proposed sensor presented a stable response during 4h under continuous monitoring. The difference of the response between six sensor preparations was <2%. The sensor was applied in the determination of total biogenic amines (neurotransmitters) in rat blood samples with success, obtaining a recovery average of 102%.

Determination of biogenic amines by capillary electrophoresis with pulsed amperometric detection

The biogenic amines, putrescine, cadaverine, spermidine and spermine were separated and quantified by capillary electrophoresis with pulsed amperometric detection. Detection potential of the pulsed amperometric detection was optimized as 0.6 V. Optimal separation of the biogenic amines was achieved using a separation buffer of 30 mM citrate at pH 3.5, while keeping the buffer in the detection cell as 20 mM NaOH. Using these conditions, the four biogenic amines were baseline separated. Extrapolated limits of detection for putrescine, cadaverine, spermidine and spermine were 400, 200, 100 and 400 nM for the standard mixture (polyamines dissolved in running buffer), respectively. These are lower than ultraviolet detection and comparable or even lower than laser-induced fluorescence detection results as reported in the literature. The number of theoretical plates was maintained at the 10(5) level, which is absolutely higher than any reported method. When applying capillary electrophoresis-pulsed amperometric detection to milk analysis, only spermidine was found in amounts varying between 0.1 and 0.5 mg/kg.

Bienzyme biosensors for glucose, ethanol and putrescine built on oxidase and sweet potato peroxidase

Amperometric biosensors for glucose, ethanol, and biogenic amines (putrescine) were constructed using oxidase/peroxidase bienzyme systems. The H(2)O(2) produced by the oxidase in reaction with its substrate is converted into a measurable signal via a novel peroxidase purified from sweet potato peels. All developed biosensors are based on redox hydrogels formed of oxidases (glucose oxidase, alcohol oxidase, or amine oxidase) and the newly purified sweet potato peroxidase (SPP) cross-linked to a redox polymer. The developed electrodes were characterized (sensitivity, stability, and performances in organic medium) and compared with similarly built ones using the 'classical' horseradish peroxidase (HRP). The SPP-based electrodes displayed higher sensitivity and better detection limit for putrescine than those using HRP and were also shown to retain their activity in organic phase much better than the HPR based ones. The importance of attractive or repulsive electrostatic interactions between the peroxidases and oxidases (determined by their isoelectric points) were found to play an important role in the sensitivity of the obtained sensors.

Real-time monitoring of histamine released from rat basophilic leukemia (RBL-2H3) cells with a histamine microsensor using recombinant histamine oxidase

To detect low levels of histamine, we developed a histamine microsensor using recombinant histamine oxidase. Histamine oxidase with a histidine tag was readily purified using a histidine affinity column. The enzyme showed higher catalytic activity on histamine than diamines (e.g., putrescine and cadaverine) or N(tau)-methylhistamine. The sensor had three carbon film electrodes modified with osmium-polyvinylpyridine-based gel containing horseradish peroxidase, histamine oxidase, and Ag. When a standard solution of histamine was aspirated at a flow rate of 2 microl/min, the detected current was proportional to the histamine concentration and the lower detection limit was 11.3 nM. When rat basophilic leukemia cells (1 x 10(6)) were stimulated by various concentrations of antigen (2, 20, and 200 ng/ml), the histamine concentrations were 0.32, 2.7, and 1.3 microM, respectively, and 20 ng/ml of antigen was found to be the optimal concentration for the antigen-antibody reaction. In contrast, when thapsigargin, an inhibitor of Ca-ATPase in the endoplasmic reticulum, was added (50, 100, and 500 nM), the detected current increased with thapsigargin concentrations and the measured histamine concentrations were 28 nM, 1.3 microM, and 2.7 microM, respectively. These results indicate that the microsensor is useful for the analysis of histamine release from mast cells.

Redox hydrogel-based amperometric bienzyme electrodes for fish freshness monitoring

This work presents the design and optimization of amperometric biosensors for the determination of biogenic amines (e.g., histamine, putrescine, cadaverine, tyramine, cystamine, agmatine, spermidine), commonly present in food products, and their application for monitoring of freshness in fish samples. The biosensors were used as the working electrodes of a three-electrode electrochemical cell of wall-jet type, operated at -50 mV vs Ag/AgCl, in a flow injection system. Two different bienzyme electrode designs were considered, one based on the two enzymes [a newly isolated and purified amine oxidase (AO) and horseradish peroxidase (HRP)] simply adsorbed onto graphite electrodes, and one when they were cross-linked to an Os-based redox polymer. The redox hydrogel-based biosensors showed better biosensors characteristics, i.e., sensitivity of 0.194 A M-1 cm-2 for putrescine and 0.073 A M-1 cm-2 for histamine, and detection limits (calculated as three times the signal-to-noise ratio) of 0.17 microM for putrescine and 0.33 microM for histamine. The optimized redox hydrogel-based biosensors were evaluated in terms of stability and selectivity, and were used for the determination of total amine content in fish samples kept for 10 days in different conditions.