RESUMEN
In recent years, the conventional preparation of silver nanoclusters (AgNCs) has attracted much attention due to their ultra-small size, tunable fluorescence, easy-to-engineer, as well as biocompatible material. Moreover, its great affinity towards cytosine bases on single-stranded DNA has led to the construction of biosensors, especially aptamers, for a broad variety of applications in food safety and environmental protection. In past years, numerous researchers paid attention to the construction of AgNCs aptasensor. Therefore, this review will be an effort to summarize the synthetic strategy along with the influences of factors on synthesis, categorize the sensing mechanism of aptamer-functionalized AgNCs biosensors, as well as their specific applications in food safety detection including heavy metal, toxin, and foodborne pathogenic bacteria. Furthermore, a brief conclusion and outlook regarding the prospects and challenges of their applications in food safety were drawn in line with the developments in DNA-AgNCs.
Asunto(s)
Aptámeros de Nucleótidos , Técnicas Biosensibles , Nanopartículas del Metal , Plata , ADN , Espectrometría de Fluorescencia , Colorantes FluorescentesRESUMEN
[This corrects the article DOI: 10.3389/fmicb.2023.1216674.].
RESUMEN
Probiotics, like lactic acid bacteria, are non-pathogenic microbes that exert health benefits to the host when administered in adequate quantity. Currently, research is being conducted on the molecular events and applications of probiotics. The suggested mechanisms by which probiotics exert their action include; competitive exclusion of pathogens for adhesion sites, improvement of the intestinal mucosal barrier, gut immunomodulation, and neurotransmitter synthesis. This review emphasizes the recent advances in the health benefits of probiotics and the emerging applications of probiotics in the food industry. Due to their capability to modulate gut microbiota and attenuate the immune system, probiotics could be used as an adjuvant in hypertension, hypercholesterolemia, cancer, and gastrointestinal diseases. Considering the functional properties, probiotics are being used in the dairy, beverage, and baking industries. After developing the latest techniques by researchers, probiotics can now survive within harsh processing conditions and withstand GI stresses quite effectively. Thus, the potential of probiotics can efficiently be utilized on a commercial scale in food processing industries.
RESUMEN
Adenosine triphosphate (ATP), an essential metabolite for active microorganisms to maintain life activities, has been widely regarded as a marker of cell activity and an indicator of microbial contamination. Herein, we designed two near-infrared (NIR) fluorescent nanoprobes named CYA@ZIF-90 and CYQ@ZIF-90 by encapsulating the NIR dye CYA/CYQ in ZIF-90 for the rapid detection of ATP. Between them, nanoprobe CYA@ZIF-90 can achieve higher NIR emission (702 nm) and rapid detection (2 min). Based on the superior spatiotemporal resolution imaging of ATP fluctuations in living cells, the applicability of CYA@ZIF-90 for imaging and detection of ATP in living bacteria was explored for the first time. The nanoprobe indirectly realizes the quantitative detection of bacteria, and the detection limit can be as low as 74 CFU mL-1. Therefore, the prepared nanoprobe is expected to become a universal ATP sensing detection tool, which can be further applied to evaluate cell apoptosis, cell proliferation, and food-harmful microbial control.
Asunto(s)
Bacterias , Colorantes Fluorescentes , Imagen Óptica/métodos , Espectroscopía Infrarroja Corta , Adenosina TrifosfatoRESUMEN
Herein, for the first time, the CRISPR-Cas12a system is combined with aptamer, cascaded dynamic DNA network circuits, and Fe3 O4 @hollow-TiO2 @MoS2 nanochains (Fe3 O4 @h-TiO2 @MoS2 NCs) to construct an efficient sensing platform for tetracycline (TC) analysis. In this strategy, specific recognition of the target is transduced and amplified into H1-H2 duplexes containing the specific sequence of Cas12a-crRNA through an aptamer recognition module and the dual amplification dynamic DNA network. Subsequently, the obtained activated Cas12a protein non-specifically cleaves the adjacent reporter gene ssDNA-FAM to dissociate the FAM molecule from the quencher Fe3 O4 @h-TiO2 @MoS2 NCs, resulting in the recovery of the fluorescence signal and further signal amplification. Particularly, the synthesized multifunctional Fe3 O4 @h-TiO2 @MoS2 NCs composites also exhibit superb magnetic separability and photocatalytic degradation ability. Under optimal conditions, the aptasensor displays a distinct linear relationship with the logarithm of TC concentration, and the limit of detection is as low as 0.384 pg mL-1 . Furthermore, the results of spiked recovery confirm the viability of the proposed aptasensor for TC quantification in real samples. This study extends the application of the CRISPR-Cas12a system in the field of analytical sensing and contributes new insights into the exploration of reliable tools for monitoring and treating hazards in food and environment.
Asunto(s)
Técnicas Biosensibles , Sistemas CRISPR-Cas , Antibacterianos , Colorantes , Sistemas CRISPR-Cas/genética , ADN , Molibdeno , Oligonucleótidos , Tetraciclina , Colorantes FluorescentesRESUMEN
Fluorescent gold (Au) nanostructures have emerged as burgeoning materials to fabricate nanomaterial assemblies which play a vital role in improving the detection sensitivity and specificity for various biomolecules. In this work, a fluorescence labelled (Rhodamine-B-Isothiocyanate) silica shell with Au metal core (AuNPs@PVP@RITC@SiO2) and a graphene-Au nanostar nanocomposite (rGO-AuNS) are presented as a metal enhanced fluorescence (MEF) material and Raman signal enhancer, respectively. Their composite (AuNPs@PVP@RITC@SiO2NPs/rGO-AuNS) was employed as a dual-mode fluorescence (FL) and surface-enhanced Raman scattering (SERS) nanoprobe for selective and sensitive detection of T-2 toxin. To comprehend the dual-modality, a core-shell nanostructure, AuNPs@PVP@RITC@SiO2, was functionalized with an aptamer (donor) and adsorbed on the surface of rGO-AuNS through electrostatic forces and π-π stacking which act as a FL quencher and SERS signal enhancer. When exposed to T-2 toxin, the apt-AuNPs@PVP@RITC@SiO2NPs move away from the surface of rGO-AuNS, resulting in the restoration of FL and reduction of the SERS signal. There was distinct linearity between the T-2 toxin concentration and the dual FL and SERS signals with lower limits of detection (LOD) of 85 pM and 12 pM, as compared to the previous methods, respectively. The developed FL and SERS aptasensor presented excellent recovery ratio and RSD in wheat and maize, respectively, as compared with the standard ELISA method. The complementary performances of the developed stratagem revealed a high correlation between the FL and SERS sensing modes with exquisite detection properties.
Asunto(s)
Nanopartículas del Metal , Toxina T-2 , Oro/química , Nanopartículas del Metal/química , Dióxido de Silicio/químicaRESUMEN
Antibiotic contamination is becoming a prominent global issue. Therefore, sensitive, specific and simple technology is desirable the demand for antibiotics detection. Biosensors based on split aptamer has gradually attracted extensive attention for antibiotic detection due to its higher sensitivity, lower cost, false positive/negative avoidance and flexibility in sensor design. Although many of the reported split aptamers are antibiotics aptamers, the acquisition and mechanism of splitting is still unknow. In this review, six reported split aptamers in antibiotics are outlined, including Enrofloxacin, Kanamycin, Tetracycline, Tobramycin, Neomycin, Streptomycin, which have contributed to promote interest, awareness and thoughts into this emerging research field. The study introduced the pros and cons of split aptamers, summarized the assembly principle of split aptamer and discussed the intermolecular binding of antibiotic-aptamer complexes. In addition, the recent application of split aptamers in antibiotic detection are introduced. Split aptamers have a promising future in the design and development of biosensors for antibiotic detection in food and other field. The development of the antibiotic split aptamer meets many challenges including mechanism discovery, stability improvement and new biosensor development. It is believed that split aptamer could be a powerful molecular probe and plays an important role in aptamer biosensor.
Asunto(s)
Aptámeros de Nucleótidos , Técnicas Biosensibles , Antibacterianos , Aptámeros de Nucleótidos/química , Sondas MolecularesRESUMEN
The beany flavor adversely influences consumer acceptance of soymilk (SM) products. Thus, in this work, the co-fermentation of isolated new yeasts (Kluyveromyces marxianus SP-1, Candida ethanolica ATW-1, and Pichia amenthionina Y) and Kluyveromyces marxianus K (a commercial yeast) along with an XPL-1 starter (including five strains of lactic acid bacteria (LAB)) was utilized to mend the beany flavor of fermented SM (FSM) beverages. Probiotic count, pH, titratable acidity, syneresis, water holding capacity, rheological characteristics, and sensory attributes were investigated. Furthermore, the free amino acids, nucleotides, and volatile compounds (VCs) were analyzed, also presenting the collected VC data by exploiting a principal component analysis (PCA) and a heatmap with a hierarchical cluster analysis. The co-fermentation with Kluyveromyces marxianus SP-1 and K remarkably enhanced the LAB strain growth and acid production, improving the rheological attributes, whereas that of yeast along with XPL-1 as a mullite starter could reduce the beany odor. PCA chart displayed that higher amounts of alcohols, ketones, acids, and esters that significantly improved the flavor quality of FSM beverages were generated throughout the co-fermentation process. The co-fermentation with Pichia amenthionina Y generated the highest acetoin (36.19%) and diacetyl (2.02%), thus improving the overall acceptance of FSM, as well as the sensory characteristics of FSM beverages with the highest umami, sweet, odorless amino acids, and umami nucleotides, and the lowest content of alcohol and inosine. Taken together, the co-fermentation of Pichia amenthionina Y along with XPL-1 within SM provides novel insights regarding the development of FSM and fermented beverages.
Asunto(s)
Kluyveromyces , Lactobacillales , Aminoácidos/metabolismo , Fermentación , Kluyveromyces/metabolismo , Lactobacillales/metabolismo , Nucleótidos/metabolismo , Levaduras/metabolismoRESUMEN
The modified natural biopolymers, recognized as environmentally friendly flocculants, are gaining tremendous attention in the field of water treatment. In this study, a novel hybrid flocculant with antibacterial activity, cinnamic acid (CA) conjugated N-(2-hydroxy)-propyl-3-trimethylammonium chitosan chloride (HTCC) derivative (HTCC-CA), was prepared via quaternary ammonium and amide reactions. The characterization, flocculation, and antibacterial activities were carried out to access the structural properties and potential application. The results of UV-vis, FT-TR, and 1H NMR confirmed the successful synthesis of HTCC-CA1-3 derivatives. XRD and TGA revealed the lower crystallinity and thermal stability of HTCC-CA1-3 derivatives than chitosan (CS). Bacterial flocculation and antibacterial tests indicated the excellent flocculation effect of HTCC-CA1-3 derivatives and showed high antibacterial activity for Escherichia coli suspension. Moreover, the mechanism of action of the derivatives was investigated via zeta potential measurements and scanning electron microscope, which can be summed up as the effective interaction between charges. The results proved that HTCC-CA derivatives are promising agents for wastewater treatment.
Asunto(s)
Quitosano , Antibacterianos/química , Antibacterianos/farmacología , Quitosano/química , Cloruros , Cinamatos/farmacología , Escherichia coliRESUMEN
Fluorescent biosensors and imaging devices have gained fervent consideration due to their prime functionality in biological. Among fluorescent nanomaterial (FNMs), the ultra-small gold nanoclusters (AuNCs) have gained promising attention with respect to extra-ordinary properties of bright fluorescence, economical synthesis, higher photostability, and biocompatibility, and deep tissue penetration. Therefore, the prior decades comprehended the revolutions in the field of real-time monitoring devices, nanotechnology-based biosensing, and bioimaging sensors. The present review primarily focuses on metal NCs (MNCs) and their advantages, a brief introduction of AuNCs along with history prospective and development, fundamental aspects regarding AuNCs quality and fluorescence, limitations and advantages of AuNCs, sensing mechanism, expected synthesis principle, and summarized the recent progress of AuNCs probe over the last 3 years (2019-2021) with their respective detection and bioimaging mechanism and synthesis principle. Moreover, the present work also serves as a novel stratagem for the preparation and potential applications of multifunctional AuNCs nano-systems responsiveness for various analytes detection and cell bioimaging with respective examples. At last, we described the challenges associated with the application of AuNCs based on recent signs of progress.
Asunto(s)
Técnicas Biosensibles , Nanopartículas del Metal , Técnicas Biosensibles/métodos , Colorantes Fluorescentes , Oro , Estudios Prospectivos , Espectrometría de Fluorescencia/métodosRESUMEN
Orange peel waste (OPW), a discarded part of orange fruit, is a rich source of essential constituents that can be transformed into highly value-added bioproducts. OPW is being generated in million tonnes globally and returns to the environment without complete benefit. Thus, a high volume of annually produced OPW in the industry requires effective valorization. In this regard, limited data is available that summarizes the broader spectrum for the sustainable fate of OPW to produce value-added bioproducts. The main objective of this treatise is to explore the sustainable production of bioproducts from OPW. Therefore, this review covers all the aspects of OPW, from its production to complete valorization. The review encompasses the extraction technologies employed for extracting different valuable bioactive compounds, such as: essential oil (EO), pectin, and carotenoids, from OPW. Furthermore, the suitability of bioconversion technologies (digestion/fermentation) in transforming OPW to other useful bioproducts, such as: biochemicals (lactic acid and succinic acid), biopolysaccharides (xanthan and curdlan gum), and bioenergy (biomethane and bioethanol) is discussed. Also, it includes the concept of OPW-based biorefineries and their development that shall play a definite role in future to cover demands for: food, chemicals, materials, fuels, power, and heat. Lastly, this review focuses on OPW-supplemented functional food products such as: beverages, yogurts, and extruded products. In conclusion, insights provided in this review maximize the potential of OPW for commercial purposes, leading to a safe, and waste-free environment.
Asunto(s)
Citrus sinensis , Aceites Volátiles , Residuos , PectinasRESUMEN
The present study emphasizes improving the overall yield, productivity and quality of xanthan by Xanthomonas campestris using different carbon sources via optimizing the fermentation media and kinetic modelling work. After optimization, six carbon sources and one nitrogen source were selected for xanthan production in 5 L bioreactor. Kinetic modelling was applied to assess the experimental fermentation data and to check its influence on scale-up production. In this work, xanthan production reached 40.65 g/L with a growth-associated rate constant (α) of 2.831, and highest specific growth rate (µm) of 0.37/h while using maltose as the sole carbon source. Furthermore, rheological properties were determined, and Herschel-Bulkley model was employed to assess the experimental data. Interestingly, xanthan obtained from sucrose and glucose showed the highest yield stress (τ0) of 12.50 ± 0.31 and 7.17 ± 0.21. Moreover, the highest xanthan molecular weight of 3.53 × 107 and 3.25 × 107 g/mol were also found with sucrose and glucose. At last, the proposed mechanism of sugar metabolism and xanthan biosynthesis pathway were described. Conclusively, maltose appeared as the best carbon source for maximum xanthan production: while sucrose and glucose gave qualitatively best results. In short, this systematically modelled approach maximizes the potential output and provides a solid base for continuous cultivation of xanthan at large-scale production.
Asunto(s)
Maltosa , Polisacáridos Bacterianos/biosíntesis , Xanthomonas campestris/crecimiento & desarrollo , Carbono/metabolismo , Carbono/farmacología , Maltosa/metabolismo , Maltosa/farmacologíaRESUMEN
A new chitosan oligosaccharide derivative (COS-N-Ger), based on geraniol (Ger) modificated onto the NH2 position of chitosan oligosaccharide (COS) via a facile method, was prepared and employed to evaluate in vitro antibacterial activity. The structures of COS-N-Ger derivatives were confirmed by FT-IR, 1H, 13C NMR, and elemental analysis. The characterization results showed successful synthesis of derivatives and the degrees of substitution (DS) of COS-N-Ger1-3 were from 0.260 to 0.283 with the yields up to 78 %. The in vitro antibacterial activity evaluation results presented a significant inhibition effect of COS-N-Ger1-3 derivatives on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) as compared to COS. Moreover, their antibacterial activities were dose-dependent and more sensitive to S. aureus than E. coli. The results provide reliable theoretical supports for exploring the application of COS derivatives in the food industry as new potential antibacterial agents.
Asunto(s)
Monoterpenos Acíclicos/química , Antibacterianos/química , Antibacterianos/farmacología , Quitosano/química , Oligosacáridos/química , Oligosacáridos/farmacología , Monoterpenos Acíclicos/farmacología , Antibacterianos/síntesis química , Quitosano/farmacología , Escherichia coli/efectos de los fármacos , Oligosacáridos/síntesis química , Staphylococcus aureus/efectos de los fármacosRESUMEN
Drug nanodelivery systems (DNDSs) are fascinated cargos to achieve outstanding therapeutic results of various drugs or natural bioactive compounds owing to their unique structures. The efficiency of several pharmaceutical drugs or natural bioactive ingredients is restricted because of their week bioavailability, poor bioaccessibility and pharmacokinetics after orally pathways. In order to handle such constraints, usage of native/natural polysaccharides (NPLS) in fabrication of DNDSs has gained more popularity in the arena of nanotechnology for controlled drug delivery to enhance safety, biocompatibility, better retention time, bioavailability, lower toxicity and enhanced permeability. The main commonly used NPLS in nanoencapsulation systems include chitosan, pectin, alginates, cellulose, starches, and gums recognized as potential materials for fabrication of cargos. Herein, this review is centered on different polysaccharide-based nanocarriers including nanoemulsions, nanohydrogels, nanoliposomes, nanoparticles and nanofibers, which have already served as encouraging candidates for entrapment of therapeutic drugs as well as for their sustained controlled release. Furthermore, the current article explicitly offers comprehensive details regarding application of NPLS-based nanocarriers encapsulating several drugs intended for the handling of numerous disorders, including diabetes, cancer, HIV, malaria, cardiovascular and respiratory as well as skin diseases.
Asunto(s)
Portadores de Fármacos/química , Nanomedicina/métodos , Nanoestructuras/química , Polisacáridos/química , Animales , Liberación de Fármacos , HumanosRESUMEN
In this study, we prepared a series of edible blend films of xanthan and curdlan by mixing different ratios of these two biopolymers. Characterization techniques like FTIR, XRD, TGA and SEM analysis were applied to investigate the newly formed films. Moreover, mechanical properties, moisture absorbance properties and water solubility of these films were also determined. The obtained results demonstrated that the strong intermolecular hydrogen bonding was observed between xanthan and curdlan at pH 5. At this pH, the xanthan-curdlan hydrogel retained the original structure of xanthan and sustained self-aggregation of xanthan chains via hydrogen bonding, which led to strong intermolecular bonding between xanthan and curdlan. Furthermore, the 5:5 and 4:6 ratios of xanthan and curdlan showed greater interaction in the blend films that resulted in their excellent miscibility. Moreover, highest tensile strength of 28.13 and 26.45 MPa were also found in the same rational of XG/CG blend films. In addition, it was observed that the curdlan incorporation improved the water solubility properties of XG/CG blend films. Conclusively, this xanthan/curdlan nexus with excellent mechanical and moisture barrier properties confirm its potential application and prospective use as food packaging material.
Asunto(s)
Biopolímeros/química , Embalaje de Alimentos/métodos , Hidrogeles/química , Polisacáridos Bacterianos/química , beta-Glucanos/química , Enlace de Hidrógeno , Concentración de Iones de Hidrógeno , Microscopía Electrónica de Rastreo , Permeabilidad , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Resistencia a la Tracción , Agua/química , Difracción de Rayos XRESUMEN
Deoxynivalenol (DON) is one of the most common contaminants of cereal grains. Efficient and environmental-friendly technology to eliminate DON is important for food safety and environmental protection. In this work, upconversion nanoparticles (UCNP) coated with titanium dioxide (TiO2) photocatalysts were synthesized. Then, a photocatalytic experiment was performed to test the impact of NaYF4:Yb,Tm@TiO2 of DON degradation. Our results showed the DON degradation rate at 10 µg/mL under simulated sunlight using NaYF4:Yb,Tm@TiO2 (6 mg/mL) approached 100% within 60 min at pH 8.0. UPLC-Q-TOF MS was used to monitor the degradation process and three degradation products were identified, namely C15H20O8, C15H20O7 and C15H20O5. Subsequently, we studied the photocatalytic degradation of DON in wheat, providing a theoretical basis for photocatalytic degradation of contaminated grain samples. This study demonstrated that UCNP@TiO2 photocatalysis has the potential for detoxification in food security applications.
RESUMEN
Yersinia enterocolitica remains a threat to public health, and a sensitive detection method is a prerequisite due to its complicated diagnosis associated with slow growth. Recently, aptamer-based detection systems have played a vital role in the development of simple, rapid, sensitive, and specific detection methods. Herein, highly specific ssDNA aptamers were screened against Y. enterocolitica at the different growth stages by whole cell-SELEX. Cells at different growth stages were harvested and incubated with an ssDNA library to get an enriched pool of specific aptamer candidates. After the 10th round of SELEX, the enriched pool was sequenced and grouped into seven families based on homology and similarity of the secondary structure. Flow cytometry analysis revealed that the aptamers M1, M5, and M7 with K d values of 37.93 ± 7.88 nM, 74.96 ± 21.34 nM, and 73.02 ± 18.76 nM had the highest affinity and specificity to the target, respectively. The selected aptamers showed binding to the different growth stages of Y. enterocolitica with a significant increase in the gated fluorescence. Our aptamer selection strategy is convenient, and the developed aptamer can be useful for an accurate and reliable detection system.
RESUMEN
Mycotoxins posit serious threats to human and animal health, and numerous efforts have been performed to detect the multiple toxins by a single diagnostic approach. To best of our knowledge, for the first time, we synthesized an aptamer induced "turn on" fluorescence resonance energy transfer (FRET) biosensor using dual-color gold nanoclusters (AuNCs), l-proline, and BSA synthesized AuNCs (Lp-AuNCs and BSA-AuNCs), with WS2 nanosheet for simultaneous recognition of aflatoxinB1 (AFB1) and zearalenone (ZEN) by single excitation. Here, AFB1 aptamer stabilized blue-emitting AuNCs (AFB1-apt-Lp-AuNCs) (at 442 nm) and ZEN aptamer functionalized with red-colored AuNCs (ZEN-apt-BSA-AuNCs) (at 650 nm) were employed as an energy donor and WS2 nanosheet as a fluorescence quencher. With the addition of AFB1 and ZEN, the change in fluorescence intensity (F.I) was recorded at 442 and 650 nm and can be used for simultaneous recognition with a detection limit of 0.34 pg mL-1 (R2 = 0.9931) and 0.53 pg mL-1 (R2 = 0.9934), respectively. Most importantly, the semiquantitative determination of AFB1 and ZEN can also be realized through photovisualization. The current approach paves a new way to develop sensitive, selective, and convenient metal nanocluster-based fluorescent "switch-on" probes with potential applications in multipurpose biosensing.
Asunto(s)
Aflatoxina B1/análisis , Color , Transferencia Resonante de Energía de Fluorescencia , Oro/química , Nanopartículas/química , Zearalenona/análisis , Aptámeros de Nucleótidos/química , Espectrometría de Fluorescencia , Sulfuros/química , Compuestos de Tungsteno/química , Zea mays/químicaRESUMEN
A "turn on" time-resolved fluorometric aptasensor is described for the simultaneous detection of zearalenone (ZEN), trichothecenes A (T-2), and aflatoxin B1 (AFB1). Multicolor-emissive nanoparticles doped with lanthanide ions (Dy3+, Tb3+, Eu3+) were functionalized with respective aptamers and applied as a bioprobe, and tungsten disulfide (WS2) nanosheets are used as a quencher of time-resolved fluorescence. The assay exploits the quenching efficiency of WS2 and the interactions between WS2 and the respective DNA aptamers. The simultaneous recognition of the three mycotoxins can be performed in a single solution. In the absence of targets, WS2 is easily adsorbed by the mixed bioprobes via van der Waals forces between nucleobases and the WS2 basal plane. This brings the bioprobe and WS2 into close proximity and results in quenched fluorescence. In the presence of targets, the fluorescence of the bioprobes is restored because the analytes react with DNA probe and modify their molecular conformation to weaken the interaction between the DNAs and WS2. Under the optimum conditions and at an excitation wavelength of 273 nm, the time-resolved fluorescence intensities (peaking at 488, 544 and 618 nm and corresponding to emissions of Dy3+, Tb3+ and Eu3+) were used to quantify ZEN, T-2 and AFB1, respectively, with detection limits of 0.51, 0.33 and 0.40 pg mL-1 and a linear range from 0.001 to 100 ng mL-1. The three mycotoxins can be detected simultaneously without mutual interference. The assay was applied to the quantification of ZEN, T-2 and AFB1 in (spiked) maize samples. This homogeneous aptamer based assay can be performed within 1 h. Conceivably, it can become an alternative to other heterogeneous methods such as the respective enzyme-linked immunosorbent assays. Graphical abstract Schematic presentation of an aptasensor for simultaneous detection of zearalenone, trichothecenes A and aflatoxin B1 using aptamer modified time-resolved fluorescence nanoparticles as signalling probes and tungsten disulfide as the quencher. This assay shows lower detection limit and requires no washing steps.
Asunto(s)
Aflatoxina B1/análisis , Aptámeros de Nucleótidos , Fluorometría/métodos , Micotoxinas/análisis , Tricotecenos/análisis , Zearalenona/análisis , Fluorometría/normas , Contaminación de Alimentos/análisis , Límite de Detección , Compuestos de Tungsteno/química , Zea maysRESUMEN
A rapid and highly sensitive time-resolved fluorescence (TRF)-based aptasensor for simultaneous recognition of mycotoxins ochratoxin A (OTA) and fumonisin B1 (FB1) was developed using multi-color, Ln3+-doped time-resolved fluorescence nanoparticles (TRF-NPs) (NaYF4: Ce, Tb and NH2-Eu/DPA@SiO2 NPs) coupled with complementary strand DNA (cDNA) as luminescence probe and aptamers-conjugated amine-functionalized Fe3O4 magnetic nanoparticles (MNPs) act as a capture probe. Under the optimized conditions, the time-resolved fluorescence intensities at 544 and 618 nm corresponded with Tb3+ and Eu3+, respectively, were used to measure FB1 (Y = 19,177.1 + (- 12,054.4)x, R2 = 0.9917) and OTA (Y = 4138.8 + (- 11,182.6)x, R2 = 0.9924), respectively. The limits of detection (LODs) for FB1 and OTA were 0.019 pg mL-1 and 0.015 pg mL-1, respectively, which were much lower than previously described methods for simultaneous recognition of mycotoxins OTA and FB1 while detection range varied from 0.0001-0.5 ng mL-1. This aptasensor was effectively applied to quantity FB1 and OTA in maize samples and results were compared with ELISA method. This is the first reported time-resolved fluorescence (TRF)-based aptasensor to detect two agriculturally important toxins in the maize. The developed aptasensor has potential to be used for detection of toxins in food safety fields. Graphical abstract.