Projects per year
Abstract
Food safety is an increasing health concern, recognised and promoted by many
institutions across the globe. Food products can be contaminated with pathogenic
microorganisms, environmental pollutants, veterinary drug residues, allergens and toxins.
Public health concerns which have been raised in relation to hazardous agents found in
food include, among others, increased cancer risk, endocrine, reproductive and
neurobehavioral systems disruption, teratogenesis, antibiotic resistance and even death in
cases of allergic reactions and acute poisoning. Some of the food hazardous agents (e.g.
pathogenic microorganisms and toxins) can even be used as biological warfare, spread
through food and agricultural chains. Thus, an adequate detection of these compounds is
also important for biosecurity. In order to safeguard consumers’ health, legislations have
been put in place both in the US and the EU. These laws specify for each health
threatening compound the maximal acceptable amounts in different food products. Besides
health issues, food safety and quality has an economical impact on the food industry,
where quality control expenses amount to about 1.5 – 2 % of the total sales. Since more
and more food products nowadays contain multiple and processed ingredients, which are
often shipped from different parts of the world, and share common production lines and
storage spaces, food safety and quality monitoring becomes a challenging task. Traditional
analytical methods require dedicated laboratories, equipment and highly trained personnel
for detection and identification of each type of hazardous agent (e.g. antibiotics, bacteria,
allergens). These techniques are also time-consuming and often expensive. There is a
growing need for multi-analyte screening methods, which will enable rapid and
simultaneous detection of multiple compounds in complex food samples. In recent years,
biosensors have been applied successfully to food analysis, incorporating the same
bioassay principals as traditional methods with transducers (optical, electrochemical, etc)
in novel, usually miniaturized, integrated analytical devices. However, most of these
biosensors still lack the desired level of the multiplexicity.
Recent developments in the field of Surface Plasmon Resonance (SPR)
technology in the direction of high-throughput systems and multi-analyte measurements
present a promising alternative for the existing systems. One of such systems is imaging
SPR (iSPR); it enables real-time and label free read-out of spatially modified surfaces (e.g.
microarrays). The aim of this study was to develop an iSPR–based biosensor, for simultaneous and quantitative detection of different health-threatening compounds in food.
To obtain a comprehensive overview on the analytical applicability of such a system,
several points were addressed. The intrinsic sensor properties, such as optical sensitivity
and robustness, of the iSPR instrument were studied. Further on, both direct and
competitive immunoassay formats for high and low molecular weight compounds
detection using the iSPR platform were evaluated. Then, the iSPR-based biosensor was
applied for detection of regulated substances in food such as antibiotic residues in milk
and allergens in cookies and chocolates. Finally, the most common drawback of using
SPR for screening in complex biological matrices, the nonspecific binding to the sensor
chip surface, was tackled. The sensitivity of both high and low molecular weight
compounds was proven to be sufficient for some of the hazardous agents detection at the
maximum residue levels, established in the EU legislation, as was demonstrated by
simultaneous detection of seven antibiotic residues in milk and twelve allergens in cookies
and dark chocolates. The analysis time takes about 10 minutes and provides quantitative
information on multiple targets, producing a fingerprint (allergenic fingerprint for instance)
of the tested food. This detailed food profile contributes to the decision making process on
the quality and safety of foods, basing it on the total picture of all target compounds
present. In order for iSPR-based biosensing to reach its full potential and to become a
widely applied routine analytical tool, the instrumental cost needs to be reduced and the
analysis further simplified, becoming cost-effective and approachable to non-trained
personnel. An additional drawback in analytical applications of a SPR sensor is the
nonspecific binding of the matrix components of complex samples to the sensor surface.
Many assays based on SPR fail due to inapplicability to measure in “real” samples. As a
possible solution to this problem, sensor chip surface engineering was suggested in this
thesis. A nanopatterned filter layer covering the sensor chip surface was found to be
effective in reducing nonspecific binding when the measurements were performed in
“raw” samples by keeping the non-soluble aggregates and big sample matrix components
beyond the sensing region of the SPR. With respect to other existing biosensors, iSPR still
lags behind in terms of sensitivity and portability.
In summary, the results of this study demonstrate that iSPR-based biosensor is a
versatile platform, which can be applied for a wide variety of fundamentally different
analytes and offers several advantages over already existing methods. SPR detection
principle eliminates the need in labelling and the instrumental set-up allows automated
analysis. High multiplexing capabilities and short measurement times are obtained with no need for complex and time consuming sample preparation steps. By using iSPR-based
biosensor, one can obtain robust and quantitative information on the target analyte
concentration, in real time and with high specificity (or broad spectrum, depending on the
assay). In conclusion, on-chip screening using iSPR, described here, presents a powerful
analytical approach towards food safety and quality monitoring which satisfies the current
need in rapid and multi-analytical devices.
institutions across the globe. Food products can be contaminated with pathogenic
microorganisms, environmental pollutants, veterinary drug residues, allergens and toxins.
Public health concerns which have been raised in relation to hazardous agents found in
food include, among others, increased cancer risk, endocrine, reproductive and
neurobehavioral systems disruption, teratogenesis, antibiotic resistance and even death in
cases of allergic reactions and acute poisoning. Some of the food hazardous agents (e.g.
pathogenic microorganisms and toxins) can even be used as biological warfare, spread
through food and agricultural chains. Thus, an adequate detection of these compounds is
also important for biosecurity. In order to safeguard consumers’ health, legislations have
been put in place both in the US and the EU. These laws specify for each health
threatening compound the maximal acceptable amounts in different food products. Besides
health issues, food safety and quality has an economical impact on the food industry,
where quality control expenses amount to about 1.5 – 2 % of the total sales. Since more
and more food products nowadays contain multiple and processed ingredients, which are
often shipped from different parts of the world, and share common production lines and
storage spaces, food safety and quality monitoring becomes a challenging task. Traditional
analytical methods require dedicated laboratories, equipment and highly trained personnel
for detection and identification of each type of hazardous agent (e.g. antibiotics, bacteria,
allergens). These techniques are also time-consuming and often expensive. There is a
growing need for multi-analyte screening methods, which will enable rapid and
simultaneous detection of multiple compounds in complex food samples. In recent years,
biosensors have been applied successfully to food analysis, incorporating the same
bioassay principals as traditional methods with transducers (optical, electrochemical, etc)
in novel, usually miniaturized, integrated analytical devices. However, most of these
biosensors still lack the desired level of the multiplexicity.
Recent developments in the field of Surface Plasmon Resonance (SPR)
technology in the direction of high-throughput systems and multi-analyte measurements
present a promising alternative for the existing systems. One of such systems is imaging
SPR (iSPR); it enables real-time and label free read-out of spatially modified surfaces (e.g.
microarrays). The aim of this study was to develop an iSPR–based biosensor, for simultaneous and quantitative detection of different health-threatening compounds in food.
To obtain a comprehensive overview on the analytical applicability of such a system,
several points were addressed. The intrinsic sensor properties, such as optical sensitivity
and robustness, of the iSPR instrument were studied. Further on, both direct and
competitive immunoassay formats for high and low molecular weight compounds
detection using the iSPR platform were evaluated. Then, the iSPR-based biosensor was
applied for detection of regulated substances in food such as antibiotic residues in milk
and allergens in cookies and chocolates. Finally, the most common drawback of using
SPR for screening in complex biological matrices, the nonspecific binding to the sensor
chip surface, was tackled. The sensitivity of both high and low molecular weight
compounds was proven to be sufficient for some of the hazardous agents detection at the
maximum residue levels, established in the EU legislation, as was demonstrated by
simultaneous detection of seven antibiotic residues in milk and twelve allergens in cookies
and dark chocolates. The analysis time takes about 10 minutes and provides quantitative
information on multiple targets, producing a fingerprint (allergenic fingerprint for instance)
of the tested food. This detailed food profile contributes to the decision making process on
the quality and safety of foods, basing it on the total picture of all target compounds
present. In order for iSPR-based biosensing to reach its full potential and to become a
widely applied routine analytical tool, the instrumental cost needs to be reduced and the
analysis further simplified, becoming cost-effective and approachable to non-trained
personnel. An additional drawback in analytical applications of a SPR sensor is the
nonspecific binding of the matrix components of complex samples to the sensor surface.
Many assays based on SPR fail due to inapplicability to measure in “real” samples. As a
possible solution to this problem, sensor chip surface engineering was suggested in this
thesis. A nanopatterned filter layer covering the sensor chip surface was found to be
effective in reducing nonspecific binding when the measurements were performed in
“raw” samples by keeping the non-soluble aggregates and big sample matrix components
beyond the sensing region of the SPR. With respect to other existing biosensors, iSPR still
lags behind in terms of sensitivity and portability.
In summary, the results of this study demonstrate that iSPR-based biosensor is a
versatile platform, which can be applied for a wide variety of fundamentally different
analytes and offers several advantages over already existing methods. SPR detection
principle eliminates the need in labelling and the instrumental set-up allows automated
analysis. High multiplexing capabilities and short measurement times are obtained with no need for complex and time consuming sample preparation steps. By using iSPR-based
biosensor, one can obtain robust and quantitative information on the target analyte
concentration, in real time and with high specificity (or broad spectrum, depending on the
assay). In conclusion, on-chip screening using iSPR, described here, presents a powerful
analytical approach towards food safety and quality monitoring which satisfies the current
need in rapid and multi-analytical devices.
Original language | English |
---|---|
Qualification | Doctor of Philosophy |
Awarding Institution |
|
Supervisors/Advisors |
|
Award date | 13 Sept 2010 |
Place of Publication | [S.l. |
Print ISBNs | 9789085857044 |
DOIs | |
Publication status | Published - 13 Sept 2010 |
Keywords
- food safety
- monitoring
- biosensors
- analytical methods
Fingerprint
Dive into the research topics of 'On-chip food safety monitoring: multi-analyte screening with imaging surface plasmon resonance-based biosensor'. Together they form a unique fingerprint.Projects
- 1 Finished
-
Microfluidic biochip for multi-analyte screening
Raz-Rebe, S. (PhD candidate) & Norde, W. (Promotor)
7/10/05 → 13/09/10
Project: PhD