Development of Flexible Dispense-Printed Electrochemical Immunosensor for Aflatoxin M1 Detection in Milk

Mycotoxins are toxic compounds produced mainly by fungi of the genera Aspergillus, Fusarium and Penicillium. In the food chain, the original mycotoxin may be transformed in other toxic compounds, reaching the consumer. A good example is the occurrence of aflatoxin M1 (AFM1) in dairy products, which is due to the presence of aflatoxin B1 (AFB1) in the animal feed. Thus, milk-based foods, such as cheese and yogurts, may be contaminated with this toxin, which, although less toxic than AFB1, also exhibits hepatotoxic and carcinogenic effects and is relatively stable during pasteurization, storage and processing. For this reason, the establishment of allowed maximum limits in dairy products and the development of methodologies for its detection and quantification are of extreme importance. There are several methods for the detection of AFM1 in dairy products. Usually, the analytical procedures go through the following stages: sampling, extraction, clean-up, determination and quantification. For the extraction stage, the use of organic solvents (as acetonitrile and methanol) is still the most common, but recent advances include the use of the Quick, Easy, Cheap, Effective, Rugged, and Safe method (QuEChERS) and proteolytic enzymes, which have been demonstrated to be good alternatives. For the clean-up stage, the high selectivity of immunoaffinity columns is still a good option, but alternative and cheaper techniques are becoming more competitive. Regarding quantification of the toxin, screening strategies include the use of the enzyme-linked immunosorbent assay (ELISA) to select presumptive positive samples from a wider range of samples, and more reliable methods—high performance liquid chromatography with fluorescence detection or mass spectroscopy—for the separation, identification and quantification of the toxin.

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“…Other studies on the application of this methodology for the quantification of AFM1 in milk have been performed (Table S1) [65,66].…”

Section: Determinationmentioning

confidence: 99%

Detection Methods for Aflatoxin M1 in Dairy Products

et al. 2020

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“…Like MWCNTs, SWCNTs have also been used to detect ATM1 compounds in milk [ 109 ]. Flexible prototypes having dispense-printed electrodes were formed where functionalized SWCNTs were coated with antibodies to increase their selectivity and sensitivity.…”

Section: Carbonaceous Sensors For the Detection Of Aflatoxin MI Molecmentioning

confidence: 99%

“…The advantages of these sensors were low fabrication cost, easy handling and a high level of customization. Figure 3 [ 109 ] shows the schematic diagram of the fabrication process of these functionalized SWCNT-based biosensors. These prototypes were formed on PET substrates having a thickness of 125 microns.…”

Section: Carbonaceous Sensors For the Detection Of Aflatoxin MI Molecmentioning

confidence: 99%

A Review of the Use of Carbon Nanotubes and Graphene-Based Sensors for the Detection of Aflatoxin M1 Compounds in Milk

Gao

Nag

et al. 2021

Sensors

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This paper presents a comprehensive review of the detection of aflatoxin compounds using carbon allotrope-based sensors. Although aflatoxin M1 and its derivative aflatoxin B1 compounds have been primarily found in milk and other food products, their presence above a threshold concentration causes disastrous health-related anomalies in human beings, such as growth impairment, underweight and even carcinogenic and immunosuppressive effects. Among the many sensors developed to detect the presence of these compounds, the employment of certain carbon allotropes, such as carbon nanotubes (CNTs) and graphene, has been highly preferred due to their enhanced electromechanical properties. These conductive nanomaterials have shown excellent quantitative performance in terms of sensitivity and selectivity for the chosen aflatoxin compounds. This paper elucidates some of the significant examples of the CNTs and graphene-based sensors measuring Aflatoxin M1 (ATM1) and Aflatoxin B1 (AFB1) compounds at low concentrations. The fabrication technique and performance of each of the sensors are shown here, as well as some of the challenges existing with the current sensors.

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“…As the most toxic AF, aflatoxin B 1 (AFB 1 ) is classified as a group 1 carcinogen by the International Agency for Research on Cancer (IARC) ( Iqbal et al, 2015 ). In addition, aflatoxin M 1 (AFM 1 ) is a hydroxylated metabolite of AFB 1 , and approximately 2–6% of AFB 1 in contaminated animal feed is converted to AFM 1 in milk ( Abera et al, 2019 ). AFM 1 mainly causes chronic hepatitis and liver tumors in humans, which was classified as group 2 and changed to group 1 carcinogen by IARC ( Karczmarczyk et al, 2016 ).…”

Section: Introductionmentioning

confidence: 99%

Aptamer-Based Fluorescence Quenching Approach for Detection of Aflatoxin M1 in Milk

et al. 2021

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Aflatoxin M1 (AFM1), one of the most toxic mycotoxins, is a feed and food contaminant of global concern. In this study, we developed a fast and simple method for detection of AFM1 based on a structure-switching signaling aptamer. This aptasensor is based on the change in fluorescence signal due to formation of an AFM1/aptamer complex. To generate the aptasensor, the specific aptamer was modified with FAM (carboxyfluorescein), and their complementary DNAs (cDNA) were modified with a carboxytetramethylrhodamine (TAMRA) quenching group. In the absence of AFM1, the aptamers were hybridized with cDNA, resulting in quenching of the aptamer fluorescence due to the proximity of the aptamer’s fluorophore to the quenching group on the cDNA. On the other hand, in the presence of AFM1, a structural switch in the aptamer was induced by formation of an AFM1/aptamer complex. Changes in the structure of the aptamer led to the release of the cDNA, causing the generation of a fluorescence signal. Thus, AFM1 concentrations could be quantitatively monitored based on the changes in fluorescences. Under optimized conditions, this assay exhibited a linear response to AFM1 in the range of 1–100 ng/mL and a limit of detection of 0.5 ng/mL was calculated. This proposed aptasensor was applied to milk samples spiked with a dilution series of AFM1, yielding satisfactory recoveries from 93.4 to 101.3%. These results demonstrated that this detection technique could be useful for high-throughput and quantitative determination of mycotoxin levels in milk and dairy products.

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Development of Flexible Dispense-Printed Electrochemical Immunosensor for Aflatoxin M1 Detection in Milk

Cited by 43 publications

References 29 publications

Detection Methods for Aflatoxin M1 in Dairy Products

Detection Methods for Aflatoxin M1 in Dairy Products

A Review of the Use of Carbon Nanotubes and Graphene-Based Sensors for the Detection of Aflatoxin M1 Compounds in Milk

Aptamer-Based Fluorescence Quenching Approach for Detection of Aflatoxin M1 in Milk

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