Environmental Engineering Reference
In-Depth Information
charging current and faster dif usion of electroactive species, which will
result in an improved response time and greater sensitivity. h e use of
lab-on-a-chip is expanding in all areas of analysis due to the advantages
of using small samples to analyze several markers/toxins, i.e., of er high
throughput analysis. h ese types of devices will be attractive for mycotoxin
analysis since several toxins may exist in the same food or feed sample.
A range of sensors are being developed for mycotoxins based on the
above technologies which can be applied on the farm or in the factory and
can be operated by unskilled personnel. Current trends to produce chip-
based micro/nanoarrays for multi-mycotoxins analysis are challenging but
possible, and will have a signii cant impact on risk assessment testing. h e
use of nanoparticles such as gold, silver, metal oxides and quantum dots
assay developments will enhance the capability of the biosensor technol-
ogy for mycotoxins analysis. Early and sensitive detection will aid in elimi-
nating these toxins from entering the food chain and preventing ill health
and protecting life.
h e development of biosensors for the rapid, reliable and low-cost deter-
mination of mycotoxins in foodstuf s has received considerable attention
in recent years, and various types of assays have already been devised for
several of the major groups of mycotoxins. One format uses the phenom-
enon of
surface plasmon resonance
(SPR) to detect the change in mass that
occurs when mycotoxin-specii c antibodies attach to a mycotoxin that has
been covalently bonded to the surface of a sensor chip. A recent application
developed and optimized for measuring deoxynivalenol in wheat extracts
gave results that were in good agreement with LC-MS data. Moreover, SPR
sensor chips with immobilized deoxynivalenol could be reused more than
500 times without signii cant loss of activity. Because the instrumentation
is now commercially available, this format could i nd widespread applica-
tion in future mycotoxin analysis. A second format using
i ber-optic probes
can be adapted for continuous monitoring of mycotoxin levels. h is sen-
sor uses the evanescent wave of light that can form around the surface of
an optical i ber. Antibodies attached to the surface of the i ber trap l uo-
rescent mycotoxins (e.g., al atoxins) or l uorescent analogues of mycotox-
ins (e.g., derivatized fumonisins) with the evanescent zone, permitting
their detection. Two dif erent benchtop devices have been designed for
the fumonisins and al atoxins. Unfortunately, most of the SPR and i ber-
optic biosensor procedures for mycotoxin analysis still require some form
of sample clean-up/preconcentration in order to be truly ef ective in the
analysis of real samples and to achieve adequate sensitivity. Moreover, the
majority of these devices lack the ability to perform simultaneous analy-
ses of multiple samples. Recently, array biosensors have been developed
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