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New Trends in Biosensors for Food and Water Safety Monitoring
Published in Sibel A. Ozkan, Bengi Uslu, Mustafa Kemal Sezgintürk, Biosensors, 2023
Maroua Hamami, Sondes Ben Aissa, Noureddine Raouafi
One of the relevant examples is a dual immunosensor developed to detect fumonisin B1 (FB1) and deoxynivalenol (DON) (59). A disposable SPCE was used as the sensing platform after its modification by AuNPs and a polypyrrole-electrochemically rGO nanocomposite film. This transducer was suitable for the effective immobilization of anti-toxins antibodies. Under optimized conditions, the LOD and linear range achieved for FB1 was 4.2 ppb and 0.2 to 4.5 ppm; and the corresponding values for DON were 8.6 ppb and 0.05 to 1 ppm. The immunosensor exhibited high sensitivity and low matrix interference when tested on spiked corn samples. Interestingly, it was possible to specifically detect the two target toxins even if present in the same sample, which makes this approach interesting for the rapid detection of different mycotoxins present in foodstuff.
What Is Mold and Why Is It Important?
Published in Jeanne Moldenhauer, Disinfection and Decontamination, 2018
Brian G. Hubka, Jeanne Moldenhauer
Mycotoxins are secondary toxic metabolites produced by fungi. These mycotoxins can be some of the most toxic substances in existence. There are at least 21 different mycotoxin classes with over 400 individual toxins produced by at least 350 fungi. Mycotoxins are potentially hazardous to man and animal health causing cancer and serious diseases. Aspergillus, Fusarium, Penicillium, and Stachybotrys are the major genera producing mycotoxins. There are several different types of mycotoxins. The types include (moldpedia.com, 2015; Hubka and Moldenhauer, 2015): Aflatoxins (AFT) are produced by Aspergillus flavus and Aspergillus parasiticus which are common contaminants in agricultural products. Based on their fluorescence under ultraviolet light (blue or green) and relative chromatogenic mobility during TLC analysis, B1, B2, G1, and G2 and M1 and M2 are the major AFT.Ochratoxin which includes Ochratoxin A, B, and C Ochratoxin A (OTA) is produced by some species such as Aspergillus ochraceous mainly in tropical regions and by Penicillium verrucosum in temperate ones.Trichothecene which is produced by Stachybotrys and includes Satratoxin-H, Vomitoxin, and T-2 mycotoxinsFumonisins include Fumonisin B1 and B2Zearalenone, an estrogenic mycotoxin produced by some Fusarium species causing problems in livestock production
Potential Applications
Published in Satyendra Mishra, Dharmesh Hansora, Graphene Nanomaterials, 2017
Satyendra Mishra, Dharmesh Hansora
In recent years, the use of anti-Stokes fluorophores such as UCNPs, which can be excited in the NIR, has successfully circumvented issues with autofluorescence and the scattering of light, which typically arise when utilising FRET in biological tissue. In particular, rare earth-containing UCNPs are able to emit high-energy photons under NIR excitation, which results from a nonlinear optical upconversion process, where the sequential absorption of two or more photons results in the emission of a single photon at a shorter wavelength [178]. As such, the use of UCNPs has made it possible to utilise FRET-based sensors directly on biological samples, wherein the use of graphene-UCNP hybrids has even greater advantages due to the superquenching properties of graphene, which greatly enhance the range of achievable FRET. As an example, Zhang et al. [173] utilised graphene-UCNP hybrids for glucose sensing [173]. In their system, they synthesised 50 nm water-soluble NaYF4:Yb,Er UCNPs modified with poly(acrylic acid), which were then conjugated with concanavalin A (conA) via EDC coupling. On the other hand, the GO sheets were functionalised with chitosan, which also occurred via EDC coupling. In terms of the underlying mechanism, conA and chitosan were able to form tight bonds, which brought the UCNPs and GO into appropriate proximity to induce FRET (81% degree of quenching). However, in the presence of glucose, the FRET process was inhibited because of competition between glucose and chitosan for conA. By utilising this system, Zhang et al. were able to achieve an LOD of 0.025 μM even in the presence of serum. Specifically, the FRET process in the presence of serum was found to be nearly the same (with minor differences in the slope), suggesting the selectivity of the sensor. Similarly, Wu et al. [179] utilised BaYF5:Yb,Er and BaYF5:Yb,Tm UCNPs functionalised with aptamers against ochratoxin A (OTA) and fumonisin B1 (FB1), respectively [179].
Evaluation of the carcinogenicity of carbon tetrachloride
Published in Journal of Toxicology and Environmental Health, Part B, 2023
Samuel M. Cohen, Christopher Bevan, Bhaskar Gollapudi, James E. Klaunig
A critical component of the MOA analysis is an evaluation of possible alternative MOA. The MOA for liver carcinogenesis (Table 8) in rodents and in humans was delineated in various reviews (Cohen 2010; Holsapple et al. 2006; Klaunig and Wang 2018). These include DNA reactive and non-DNA reactive MOA. The non-DNA reactive MOA is either receptor-mediated or non-receptor-mediated. Receptor-mediated MOA includes estrogen stimulation and cytotoxicity secondary to specific reactions, such as those related to HMG-CoA reductase inhibition of various enzyme in the porphyrin-heme synthesis pathway. Other MOA that are receptor-mediated appear to be rodent-specific and include PPARα activation (peroxisome proliferation) and cytochrome enzyme induction (constitutive androstane receptor (CAR), pregnane X receptor (PXR), aryl hydrocarbon receptor (AHR)). Non-receptor mediated MOA includes cytotoxicity, infections, iron or copper overload and increased apoptosis (for example, fumonisin B1), as well as several inherited disorders in humans (Cohen 2010).
Ozone as a Fungicidal and Detoxifying Agent to Maize Contaminated with Fumonisins
Published in Ozone: Science & Engineering, 2022
Daniel Francis Ribeiro, Lêda Rita D’ Antonino Faroni, Marco Aurélio Guerra Pimentel, Lucas Henrique Figueiredo Prates, Fernanda Fernandes Heleno, Ernandes Rodrigues De Alencar
Fumonisins are polar secondary metabolites that have 20 carbon atoms containing methyl and amino groups and in which the hydroxyl groups on C14 and C15 are esterified with tricarboxylic acid (Abrunhosa et al. 2016). Fumonisins from the A, B, C, and P series can be found, but those from the B series (FBs) are the most important regarding safety for consumption and are frequently found in maize (Abrunhosa et al. 2016; Rheeder, Marasas, and Vismer 2002; Seo and Lee 1999). In the group of fumonisins of the series B, fumonisin B1 (FB1) shows greater occurrence, but fumonisin B2 (FB2) and fumonisin B3 (FB3) are also found. Among others, Fusarium verticillioides and Fusarium proliferatum are fungi species that synthesize fumonisins of series B (Marin et al. 1995; Pitt and Hocking 2009).
Settled dust assessment in clinical environment: useful for the evaluation of a wider bioburden spectrum
Published in International Journal of Environmental Health Research, 2021
Carla Viegas, Beatriz Almeida, Ana Monteiro, Inês Paciência, João Cavaleiro Rufo, Elisabete Carolino, Anita Quintal-Gomes, Magdalena Twarużek, Robert Kosicki, Geneviéve Marchand, Liliana Aranha Caetano, Susana Viegas
Mycotoxins were separated on a chromatographic column Gemini NX-C18 (150 × 4.6 mm, 3 μm) (Phenomenex, Torrance, CA, USA); mobile phase (A: water + 5 mM ammonium acetate + 1% acetic acid, B: methanol + 5 mM ammonium acetate + 1% acetic acid) mobile phase flow rate: 0.75 mL.min−1, injection volume: 7 μL. Several mycotoxins were assessed, namely: patulin, nivalenol, deoxynivalenol-3-glucoside, deoxynivalenol, fusarenon-X, α-zearalanol, β-zearalanol, β-zearalenol, α-zearalenol, zearalanone, zearalenone, T2 tetraol, deepoxydeoxynivalenol, neosolaniol, 15-acetyldeoxynivalenol, 3-acetyldeoxynivalenol, monoacetoxyscirpenol, diacetoxyscirpenol, aflatoxin M1, aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, fumonisin B1, fumonisin B2, fumonisin B3, T2 triol, roquefortine C, griseofulvin, T2 toxin, HT2 toxin, ochratoxin A, ochratoxin B, mycophenolic acid, mevinolin and sterigmatocystin. The limits of detection (LOD) and quantification (LOQ) obtained for each mycotoxin with the analytical method used are presented in Table 5.