Anti-Ochratoxin A monoclonal antibody, clone 6H5i4 [Biotin]

Grapes are consumed throughout the world in different ways, ranging from fresh fruit to processed products. Regardless of the product, risk management starts in preharvest stages to control initial development of mycotoxigenic fungi and avoid consequent problems in the whole chain. The main concern in grapes and grape products is the presence of black Aspergillus species and the subsequent production of ochratoxin A. However, other mycotoxigenic fungi have been detected and may need further attention. The adoption of crop management strategies, such as selection of varieties, training system, and soil management, can reduce fungal proliferation. Biological methods can also be used to inhibit fungal contamination. These methods can substitute for chemical approaches and be used in later phases of grape processing to allow safe storage. Due to the wide range of products that can be obtained from grapes, different fungal species can be responsible for postharvest deterioration. Taking this into account, the aim of this work is to review strategies for mitigation of mycotoxin risk in the whole grape chain considering data on the occurrence and development of mycotoxigenic fungi and mycotoxin biosynthesis.

A new fluorescence aptasensor for Ochratoxin A (OTA) analysis in corn and barley flour was developed owing to the favourable quenching function of cobalt oxyhydroxide (CoOOH) nanosheets. The first combination of graphitic carbon nitride quantum dots (g-CNQDs) and CoOOH nanosheets as efficient energy donor-acceptor pair was reported, and the quenching mechanism was proved by investigating the fluorescence lifetime of g-CNQDs. The aptamer-modified g-CNQDs (g-CNQDs-apt) were adsorbed onto CoOOH nanosheets surface by van der Waals force. Consequently, the Forster resonance energy transfer (FRET) from g-CNQDs-apt to CoOOH nanosheets was initiated, leading to quenched fluorescence. With the addition of OTA, the linear aptamer specifically bound with OTA to form G-quadruplex, which had relatively weak interaction with the CoOOH nanosheets and separated from the nanosheets surface. Thus, the FRET process between g-CNQDs-apt and CoOOH nanosheets was hindered, leading to the fluorescence of g-CNQDs-apt recovered clearly. The developed aptasensor exhibited acceptable detection limit with 0.5 nM and desirable linear relationship from 1 nM to 140 nM. Meanwhile, the aptasensor possessed multiple advantages, including easy operation, rapid detection and high selectivity. Moreover, the aptamer sensing platform was favorably applied for OTA determination in cereal (barley and corn flour), in which the recoveries varied from 94.5% to 101% with the relative standard deviation under 2.24%.