Progress 10/01/12 to 02/04/16
Outputs
Target Audience:The target audiences are academia and industry. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?A PhD studnet was trained. Another PhD studnet and a post-doctoral Research Associate had the opportunity to assist with the project and learn about mycotaxincontamination in foods. How have the results been disseminated to communities of interest?Yes. Via conference presentations and peer-review journal articles What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
We have designed and developed an electrochemical immunosensing method for rapid and sensitive detection of two mycotoxins, fumonisin B1 (FB1) and deoxynivalenol (DON). A disposable screen-printed carbon electrode (SPE) was used as sensing platform. The working electrode part of SPE was modified by gold nanoparticles (AuNPs) and polypyrrole (PPy)-electrochemically reduced graphene oxide (ErGO) nanocomposite film for effective anti-toxin antibody immobilization, enhanced electrical conductivity, and biocompatibility. Under optimized test conditions, the limit of detection and linear range achieved for FB1 were 4.2 ppb and 0.2 to 4.5 ppm (%RSD=4.9%); and the corresponding values for DON were 8.6 ppb and 0.05 to 1 ppm (%RSD=5.7%). The immunosensor can specifically detect the target toxin in co-existing toxins environment. The sensor performance exhibited high sensitivity and low matrix interference when tested using extracts obtained from spiked corn samples. Hence, our electrochemical immunosensing scheme can be adopted for highly sensitive and rapid detection of multiple co-contaminant mycotoxins in food and feed products.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Gunasekaran, S. 2015. Biosensor for Detecting Mycotoxins in Grains. NC 213 Winter Meeting. Kansas City, KS.
- Type:
Journal Articles
Status:
Submitted
Year Published:
2016
Citation:
Lu L, Seenivasan R, Wang Y-C, Yu J-H, Gunasekaran S. 2016. An Electrochemical Immunosensor for Rapid and Sensitive Detection of Mycotoxins Fumonisin B1 and Deoxylnivalenol. Biosensors and Bioelectronics (submitted)
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2014
Citation:
Lu L, S Gunasekaran. 2014. Nanomaterial-Based Electrochemical Immunosensor for the Detection of Aflatoxins in Grains. Abstract No. 253-03. IFT Annual Meeting, June 21 24, 2014, New Orleans, LA
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2015
Citation:
Lu L, S Gunasekaran. 2015. Electrochemical Immunosensor for the Detection of Aflatoxin B1 in Grains. Fourth Annual WARF Discovery Challenge, University of Wisconsin-Madison, April 9.
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Progress 10/01/13 to 09/30/14
Outputs
Target Audience: Academicians and industry scientists. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? One graduate student is working towards her PhD degree. How have the results been disseminated to communities of interest?
Nothing Reported
What do you plan to do during the next reporting period to accomplish the goals? To improve the stability of functionalized electrode, as well as provide more -COOH groups for antibody immobilization, we will improve our electrode design. First, pyrrole (a type of conducting material) will be polymerized by electrochemical method to produce a polypyrrole film on electrode surface instead of PDDA. In addition, we will use gold nanoparticles instead of carboxylated carbon nanotube (CNT) as another layer to increase the electrode's conductivity. Because a 3-mercaptopropionic acid could serve as a linker and bind with gold nanoparticles via Au-S bond, and thus, the -COOH end of the acid is free for other interactions, which will provide more available -COOH groups compared to the previous strategy. Once the new sensor design is in place, we will test its effectiveness and further optimize its performance.
Impacts
What was accomplished under these goals?
An electrochemical immunosensor has been developed for the detection of for mycotoxins. At the first stage, the sensor has been developed and optimized to detect Aflatoxin B1 (AFB1), and at the second stage, the sensor has been applied to detect Fumonisin B1 (FUM B1). Since antibody-antigen complex blocks electron transfer to the electrode surface, the observed peak current will reduce with increasing aflatoxin concentration. Our results show that with appropriate antibody loading, the detection limit of the developed sensor could go down to 0.01 ppb (parts per billion), and the sensor is able to detect AFB1 up to 90 ppb in samples. We also developed a biosensor for FUM B1 detection when the sensor is functionalized with anti-fumonisin antibody. Based on all experiments that have been done, a potential problem has been identified: the conducting polymer poly(diallyldimethylammonium chloride) (PDDA) that was used for electrode modification prior to antibodies shows relatively poor stability on electrode surface, which makes the conductivity of modified electrode not consistent. In summary, we are fabricting nanomaterial-functionalized immuosensors for sensititive detection of mycotoxin contamination in food grains. So far, we have developed and tested a sensor for detecting aflatoxin B1 and are now working on detecting fumonisin.
Publications
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Progress 01/01/13 to 09/30/13
Outputs
Target Audience: Research and academic personnel. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? One graduate student is working on this project. How have the results been disseminated to communities of interest? Yes. An abstract is submitted for presenattion at the Institute of Food Technologists (IFT) Annual Meeting. What do you plan to do during the next reporting period to accomplish the goals? We will continue our work to improve sensor detection sensitivity and its robustness by testing in real matrices.
Impacts
What was accomplished under these goals?
Mycotoxin-contamination of food and feed grains such as corn and wheat could pose serious health risks and economic losses. Aflatoxin B1 (AFB1) is the most common mycotoxin that can easily withstand digestion or high temperature treatments and retain its toxicity in foods. Therefore, routine monitoring of the presence of AFB1 and other aflatoxins in food and feed grains prior to their end use is important. A gold nanoparticles (AuNPs)-based electrochemical immunosensor was designed to rapidly detect trace amounts of AFB1 in grains. AuNPs were covalently attached to a carbon screen-printed electrode (SPE) surface, then anti-AFB1 antibodies (aAFB1) were linked to the AuNPs via cross linkers for fabrication of the Carbon-AuNPs-aAFB1 immunoelectrode. Bovine serum albumin (BSA)-conjugated AFB1 (BSA-AFB1) was used to compete for antibody binding sites with AFB1 in a microfluidic system, resulting in changes of electrochemical signals. Scanning electron microscopy images of the immunoelectrode show relatively uniform and high surface coverage of antibodies. Cyclic voltammetry (CV) data show a higher peak current and smaller peak separation corresponding to higher AFB1 concentration. Since BSA usually serves as a blocking agent due to its large size, our data suggest that aAFB1 successfully bind to AFB1 instead of BSA-AFB1, resulting in less blocking effect on electron transfer. The CV responses confirmed that the fabricated immunoelectrode can be used to detect AFB1 in the range of 5 to100 ng/mL. The sensing process could be completed within 30 minutes. Our sensor platform can be further developed to allow simultaneous detection of different and/or additional analytes (e.g., different aflatoxins). The total number of analytes that can be simultaneously detected is limited only by the number of channels available in the sensor instrumentation.
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2012
Citation:
Yang J, S Ko, S Gunasekaran. 2012. A colorimetric biosensor based on gold nanoparticles for self-indicating toxin detections in food via competitive binding with toxin analogs. 224th ACS National Meeting and Exposition (Abstract No.: 12493), August 18-22, Boston, MA.
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: Among the most important issues facing grain and livestock producers in Wisconsin and elsewhere are preventing mycotoxin contamination of food and feed and reducing the deleterious effects of mycotoxins on livestock. Our focus in this project is to detect aflatoxins and fumonisons, the two most common co-contaminants of the number one grain crop in Wisconsin: corn. Early, rapid, and simultaneous detection of these co-contaminants would help avert potentially calamitous food safety and security problems. The presence of unacceptable levels of mycotoxins in food and feed grains also has global trade implications, which could result in a tremendous economic loss. We have started assembling units for synthesizing nanoparticles to modify our electrodes to be used in the electrochemical sensing system. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Academic and industry research and development personnel. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
The electrochemical detection sensor platform we develop will be broad-based such that mycotoxins other than aflatoxins and fumonisins and even entities other than mycotoxins can be detected rapidly, selectively, and sensitively.
Publications
- No publications reported this period
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