Designed Strategies for Fluorescence-Based Biosensors for the Detection of Mycotoxins (original) (raw)
Related papers
Emerging nanotechnology for detection of mycotoxins in food and feed
International Journal of Food Sciences and Nutrition, 2015
The term mycotoxin was coined for toxic metabolites secreted by some fungi in food, food products and feed. The most prominent mycotoxins include aflatoxins (AFs), deoxynivalenol, zearalenone, ochratoxin, fumonisin and patulin. Among these some are proved to be strong carcinogenic agents such as AFs B1 while others are under suspicion to have carcinogenic effects. Ingestion of such mycotoxin-contaminated food and feed pose to a threat, mycotoxicoses. Various conventional techniques are available for the detection of mycotoxins, but unfortunately as a consequence of their constraint, the development of new and rapid techniques is the need of the hour. The use of nanotechnology for the development of nanobiosensors would be the alternative sensitive methods for the rapid detection of mycotoxins. Implementation of nanomaterials in the fabrication of nanobiosensors and their use for the detection of the mycotoxins in food and feed is the centre of interest of this review. We have inventoried nanomaterials applied for weaving nanobiosensors, which includes carbon nanotubes, nanowires, nanoparticles, quantum dots, nanorods and nanofibers. In addition, we have extensively reviewed available nanobiosensors specific for different mycotoxins, their advantages and challenges.
Nanomaterial-Based Biosensors for Food Toxin Detection
Applied Biochemistry and Biotechnology, 2014
There is an increased interest toward the development of bioelectronic devices for food toxin (mycotoxins) detection. Mycotoxins are highly toxic secondary metabolites produced by fungi like Fusarium, Aspergillus, and Penicillium that are frequently found in crops or during storage of food including cereals, nuts, fruits, etc. The contamination of food by mycotoxins has become a matter of increasing concern. High levels of mycotoxins in the diet can cause adverse, acute, and chronic effects on human health and a variety of animal species. Side effects may particularly affect the liver, kidney, nervous system, endocrine system, and immune system. Among 300 mycotoxins known till date, there are a few that are considered to play an important part in food safety, and for these, a range of analytical methods have been developed. Some of the important mycotoxins include aflatoxins, ochratoxins, fumonisins, citreoviridin, patulin, citrinin, and zearalenon. The conventional methods of analysis of mycotoxins normally require sophisticated instrumentation, e.g., liquid chromatography with fluorescence or mass detectors, combined with extraction procedures for sample preparation. Hence, new analysis tools are necessary to attain more sensitive, specific, rapid, and reliable information about the desired toxin. For the last about two decades, the research and development of simpler and faster analytical procedures based on affinity biosensors has aroused much interest due to their simplicity and sensitivity. The nanomaterials have recently had a great impact on the development of biosensors. The functionalized nanomaterials are used as catalytic tools, immobilization platforms, or as optical or electroactive labels to improve the biosensing performance to obtain higher sensitivity, stability, and selectivity. Nanomaterials, such as carbon nanomaterials (carbon nanotubes and graphene), metal nanoparticles, nanowires, nanocomposites, and nanostructured metal oxide nanoparticles are playing an increasing role in the design of sensing and biosensing systems for mycotoxin determination. Furthermore, these nanobiosystems are also bringing advantages in terms of the design of novel food toxin detection strategies. We will focus on some of the recent results related to fabrication of nanomaterial-based biosensors for food toxin detection obtained in our laboratories.
[INVITED] Novel optical biosensing technologies for detection of mycotoxins
Optics & Laser Technology, 2019
This work reviews our recent progress in development of novel optical methods of detection of mycotoxins in direct assay with either specific antibodies or aptamers. The main method in this work was the total internal reflection ellipsometry (TIRE) combined with LSPR transducers based on gold nano-structures produced by annealing of thin gold films. The gold nano-islands produced were characterised with SEM, AFM, UV-visible absorption spectroscopy, and spectroscopic ellipsometry. The combination of TIRE and LSPR offers superior refractive index sensitivity as compared to traditional UV-vis absorption spectroscopy. The limitations of LSPR related to a short evanescent field decay length can be overcome using small-size bio-receptors, such as halfantibodies and aptamers. The achieved sensitivity of detection of mycotoxins in 0.01ppb level of concentration is sufficient for the use of this method for analysis of agriculture products, food and feed on the presence of mycotoxins. Even higher sensitivity in sub-ppt level was achieved with another optical biosensor developed recently; it is based on optical planar waveguide operating as polarization interferometer (PI). This method is promising for development of portable, highly sensitive, and simple to use biosensors suitable for point-of-need detection of mycotoxins.
Recent advances in mycotoxins detection
Biosensors and Bioelectronics, 2016
Mycotoxins contamination in both food and feed is inevitable. Mycotoxin toxicity in foodstuff can occur at very low concentrations necessitating early availability of sensitive and reliable methods for their detection. The present research thrust is towards the development of a user friendly biosensor for mycotoxin detection at both academic and industrial levels in replace of conventional expensive chromatographic and ELISA techniques. This review critically analyze the recent research trend towards the construction of immunosensor, aptasensor, enzymatic sensors and others for mycotoxin detection with a reference to label and label free methods, synthesis of new material including nano dimension, and transuding techniques. Technological aspects in the development of biosensors for mycotoxin detection, current challenges and future prospects are also included to provide a overview and suggestions for future research directions.
Applications of Molecular Spectroscopy to Current Research in the Chemical and Biological Sciences, 2016
The presence of mycotoxins in food products is a major worldwide problem. Nowadays, mycotoxins can only be detected by the use of sample-based chemical analyses. Therefore, we demonstrate the use of one-and two-photon-induced fluorescence spectroscopy for the non-destructive detection of mycotoxins in unprocessed food products. We first explain our optical setup , which is able to measure the localized oneand two-photon-induced fluorescence spectra. Following, as a case study, the detection of aflatoxin in maize kernels is discussed. We present our research methodology, from the characterization of the fluorescence of pure aflatoxin, to the study of the one-and two-photon-induced fluorescence spectra of maize kernels and the development of an optical detection criterion. During both one-and two-photon-induced fluorescence processes, the fluorescence of the aflatoxin influences the intrinsic fluorescence of the maize. Based on the fluorescence spectrum between 400 and 550 nm, a detection criterion to sense the contaminated kernels is defined. Furthermore, we successfully monitored the localized contamination level on the kernel's surface, showing both contaminated kernels with a high contamination in a limited surface area (a few square millimetres) and kernels with a low contamination spread over a large surface area (up to 20 mm 2). Finally, the extensibility of our research methodology to other fluorescent mycotoxins is discussed.
Highly reproducible and sensitive detection of mycotoxins by label-free biosensors
Sensors and Actuators B: Chemical, 2017
Enhancement of sensitivity and reproducibility of measuring the concentration of small molecules (haptens) is crucially important for a wide variety of applications. The immunochemical detection of haptens by different biosensors is commonly realized by competitive assays that strongly depend on sorption capacity of the sensor chip and accessibility of antigen determinants in a conjugate immobilized on its surface. Here, we propose a method for significant improvement of limits of label-free detection of haptens due to enhancement of reproducibility of the competitive assay by taking into account the specific sorption capacity within the sensing area. The method is validated by mycotoxin detection in complex food matrices such as white wine. The limits of detection of 0.25 ng/ml, 0.48 ng/ml and 1 ng/ml are achieved for ochratoxin A, zearalenone, and aflatoxin B1, respectively, using compact label-free interferometric biosensors that employ microscope cover slips as affordable single-used sensor chips. The proposed method of drastic improvement of reproducibility of competitive assays can be used by any other label-free biosensors. This feature combined with the well-known advantages of label-free biosensors could make them attractive for precise, rapid, sensitive and multiplex detection of small molecules in food analysis, medicine, biosafety and environmental monitoring, etc.
Thin Films Sensor Devices for Mycotoxins Detection in Foods: Applications and Challenges
Chemosensors, 2019
Mycotoxins are a group of secondary metabolites produced by different species of filamentous fungi and pose serious threats to food safety due to their serious human and animal health impacts such as carcinogenic, teratogenic and hepatotoxic effects. Conventional methods for the detection of mycotoxins include gas chromatography and high-performance liquid chromatography coupled with mass spectrometry or other detectors (fluorescence or UV detection), thin layer chromatography and enzyme-linked immunosorbent assay. These techniques are generally straightforward and yield reliable results; however, they are time-consuming, require extensive preparation steps, use large-scale instruments, and consume large amounts of hazardous chemical reagents. Rapid detection of mycotoxins is becoming an increasingly important challenge for the food industry in order to effectively enforce regulations and ensure the safety of food and feed. In this sense, several studies have been done with the aim ...
Recent trends in analysis of mycotoxins in food using carbon-based nanomaterials
Journal of Food and Drug Analysis
Mycotoxins (MYTs), a class of low molecular weight secondary metabolites produced by filamentous fungi in food and feed, pose serious global threat to both human health and world economy. Due to their mutagenic, teratogenic, carcinogenic and immunosuppressive effects, the International Agency for Research on Cancer has classified various MYTs under Group 1 to 3 category with aflatoxins being designated under Group 1 category (carcinogenic to humans). Also, the presence of MYTs in trace amounts in diverse food matrices necessitates exploration of highly sensitive methods for onsite analysis. Although conventional chromatographic methods are highly sensitive, they are expensive, tedious and cannot be applied for rapid onsite analysis. In recent years the application of nanomaterials especially carbon-based nanomaterials (CNMs) in the fabrication of low-cost and miniaturized electrochemical and optical sensors has enabled rapid onsite analysis of MYTs with high sensitivity and specificity. Moreover, the CNMs are employed as effective solid phase extraction (SPE) adsorbents possessing high specific surface area for effective enrichment of MYTs to improve the sensitivity of chromatographic methods for MYT analysis in food. This article aims to overview the recent trends in the application of CNMs as SPE adsorbents for sample pretreatment in chromatographic methods as well as in the fabrication of highly sensitive electrochemical and optical sensors for rapid analysis of MYTs in food. Initially, the efficiency of various functionalized CNMs developed recently as adsorbent in packed SPE cartridges and dispersive SPE adsorbent/purification powder is discussed. Then, their application in the development of various electrochemical immunosensors involving functionalized carbon nanotubes/nanofibers, graphene oxide, reduced graphene oxide and graphene quantum dots is summarized. In addition, the recent trends in the use of CNMs for fabrication of electrochemical and fluorescence aptasensors as well as some other colorimetry, fluorometry, surface-enhanced Raman spectroscopy and electrochemical based sensors are compared and tabulated. Collectively, this review article can provide a research update on analysis of MYTs by carbon-based nanomaterials paving a way for identifying future perspectives.
Ultrasensitive mycotoxin detection by STING sensors
Biosensors and Bioelectronics, 2010
Signal Transduction by Ion Nano Gating (STING) technology is a label-free biosensor capable of identifying DNA and proteins. Based on a functionalized quartz nanopipette, the STING sensor includes specific recognition elements for analyte discrimination based on size, shape and charge density. A key feature of this technology is that it doesn't require any nanofabrication facility; each nanopipette can be easily, reproducibly, and inexpensively fabricated and tailored at the bench, thus reducing the cost and the turnaround time. Here, we show that STING sensors are capable of the ultrasensitive detection of HT-2 toxin with a detection limit of 100 fg/ml and compare the STING capabilities with respect to conventional sandwich assay techniques.