Rapid and Label-Free Immunosensing of Shiga Toxin Subtypes with Surface Plasmon Resonance Imaging
Shiga toxin-producing <i>Escherichia coli</i> (STEC) are responsible for gastrointestinal diseases reported in numerous outbreaks around the world as well as in the United States. Current detection methods have limitation to implement for rapid field-deployable detection with high volume...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-04-01
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| Series: | Toxins |
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| Online Access: | https://www.mdpi.com/2072-6651/12/5/280 |
| _version_ | 1797569557052784640 |
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| author | Bin Wang Bosoon Park Jing Chen Xiaohua He |
| author_facet | Bin Wang Bosoon Park Jing Chen Xiaohua He |
| author_sort | Bin Wang |
| collection | DOAJ |
| description | Shiga toxin-producing <i>Escherichia coli</i> (STEC) are responsible for gastrointestinal diseases reported in numerous outbreaks around the world as well as in the United States. Current detection methods have limitation to implement for rapid field-deployable detection with high volume of samples that are needed for regulatory purposes. Surface plasmon resonance imaging (SPRi) has proved to achieve rapid and label-free screening of multiple pathogens simultaneously, so it was evaluated in this work for the detection of Shiga toxins (Stx1a and Stx2a toxoids were used as the less toxic alternatives to Stx1 and Stx2, respectively). Multiple antibodies (Stx1pAb, Stx1-1mAb, Stx1-2mAb, Stx1d-3mAb, Stx1e-4mAb, Stx2pAb, Stx2-1mAb, Stx2-2mAb, and Stx2-10mAb) were spotted one by one by programed microarrayer, on the same high-throughput biochip with 50-nm gold film through multiple crosslinking and blocking steps to improve the orientation of antibodies on the biochip surface. Shiga toxins were detected based on the SPRi signal difference (ΔR) between immobilized testing antibodies and immunoglobulin G (IgG) control. Among the antibodies tested, Stx1pAb showed the highest sensitivity for Stx1 toxoid, with the limit of detection (LOD) of 50 ng/mL and detection time of 20 min. Both Stx2-1mAb and Stx2-2mAb exhibited high sensitivity for Stx2 toxoid. Furthermore, gold nanoparticles (GNPs) were used to amplify the SPRi signals of monoclonal antibodies in a sandwich platform. The LOD reached the level of picogram (pg)/mL with the help of GNP-antibody conjugate. This result proved that SPRi biochip with selected antibodies has the potential for rapid, high-throughput and multiplex detection of Shiga toxins. |
| first_indexed | 2024-03-10T20:12:16Z |
| format | Article |
| id | doaj.art-43d015f209944f0e87713d8f88ea5ad3 |
| institution | Directory Open Access Journal |
| issn | 2072-6651 |
| language | English |
| last_indexed | 2024-03-10T20:12:16Z |
| publishDate | 2020-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Toxins |
| spelling | doaj.art-43d015f209944f0e87713d8f88ea5ad32023-11-19T22:48:19ZengMDPI AGToxins2072-66512020-04-0112528010.3390/toxins12050280Rapid and Label-Free Immunosensing of Shiga Toxin Subtypes with Surface Plasmon Resonance ImagingBin Wang0Bosoon Park1Jing Chen2Xiaohua He3USDA, ARS, SEA, USNPRC, 950 College Station Rd, Athens, GA 30605, USAUSDA, ARS, SEA, USNPRC, 950 College Station Rd, Athens, GA 30605, USAFood Science Center, Merieux NutriSciences (China), Shanghai 201112, ChinaUSDA, ARS, PWA, WRRC, 800 Buchanan Street, Albany, CA 94710, USAShiga toxin-producing <i>Escherichia coli</i> (STEC) are responsible for gastrointestinal diseases reported in numerous outbreaks around the world as well as in the United States. Current detection methods have limitation to implement for rapid field-deployable detection with high volume of samples that are needed for regulatory purposes. Surface plasmon resonance imaging (SPRi) has proved to achieve rapid and label-free screening of multiple pathogens simultaneously, so it was evaluated in this work for the detection of Shiga toxins (Stx1a and Stx2a toxoids were used as the less toxic alternatives to Stx1 and Stx2, respectively). Multiple antibodies (Stx1pAb, Stx1-1mAb, Stx1-2mAb, Stx1d-3mAb, Stx1e-4mAb, Stx2pAb, Stx2-1mAb, Stx2-2mAb, and Stx2-10mAb) were spotted one by one by programed microarrayer, on the same high-throughput biochip with 50-nm gold film through multiple crosslinking and blocking steps to improve the orientation of antibodies on the biochip surface. Shiga toxins were detected based on the SPRi signal difference (ΔR) between immobilized testing antibodies and immunoglobulin G (IgG) control. Among the antibodies tested, Stx1pAb showed the highest sensitivity for Stx1 toxoid, with the limit of detection (LOD) of 50 ng/mL and detection time of 20 min. Both Stx2-1mAb and Stx2-2mAb exhibited high sensitivity for Stx2 toxoid. Furthermore, gold nanoparticles (GNPs) were used to amplify the SPRi signals of monoclonal antibodies in a sandwich platform. The LOD reached the level of picogram (pg)/mL with the help of GNP-antibody conjugate. This result proved that SPRi biochip with selected antibodies has the potential for rapid, high-throughput and multiplex detection of Shiga toxins.https://www.mdpi.com/2072-6651/12/5/280Surface plasmon resonance imagingShiga toxinfoodborne pathogenlabel-free detectionnanoparticlesandwich immunoassay |
| spellingShingle | Bin Wang Bosoon Park Jing Chen Xiaohua He Rapid and Label-Free Immunosensing of Shiga Toxin Subtypes with Surface Plasmon Resonance Imaging Toxins Surface plasmon resonance imaging Shiga toxin foodborne pathogen label-free detection nanoparticle sandwich immunoassay |
| title | Rapid and Label-Free Immunosensing of Shiga Toxin Subtypes with Surface Plasmon Resonance Imaging |
| title_full | Rapid and Label-Free Immunosensing of Shiga Toxin Subtypes with Surface Plasmon Resonance Imaging |
| title_fullStr | Rapid and Label-Free Immunosensing of Shiga Toxin Subtypes with Surface Plasmon Resonance Imaging |
| title_full_unstemmed | Rapid and Label-Free Immunosensing of Shiga Toxin Subtypes with Surface Plasmon Resonance Imaging |
| title_short | Rapid and Label-Free Immunosensing of Shiga Toxin Subtypes with Surface Plasmon Resonance Imaging |
| title_sort | rapid and label free immunosensing of shiga toxin subtypes with surface plasmon resonance imaging |
| topic | Surface plasmon resonance imaging Shiga toxin foodborne pathogen label-free detection nanoparticle sandwich immunoassay |
| url | https://www.mdpi.com/2072-6651/12/5/280 |
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