Ag@Au Core–Shell Porous Nanocages with Outstanding SERS Activity for Highly Sensitive SERS Immunoassay
A highly sensitive immunoassay of biomarkers has been achieved using 4-mercaptobenzoic acid-labeled Ag@Au core–shell porous nanocage tags and α-fetoprotein immuno-sensing chips. The Ag@Au porous nanocages were uniquely synthesized by using an Ag core as a self-sacrificial template...
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MDPI AG
2019-03-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/19/7/1554 |
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| author | Yaqi Huang Dajie Lin Mengting Li Dewu Yin Shun Wang Jichang Wang |
| author_facet | Yaqi Huang Dajie Lin Mengting Li Dewu Yin Shun Wang Jichang Wang |
| author_sort | Yaqi Huang |
| collection | DOAJ |
| description | A highly sensitive immunoassay of biomarkers has been achieved using 4-mercaptobenzoic acid-labeled Ag@Au core–shell porous nanocage tags and α-fetoprotein immuno-sensing chips. The Ag@Au porous nanocages were uniquely synthesized by using an Ag core as a self-sacrificial template and reducing agent, where the slow reaction process led to the formation of a porous Au layer. The size of the remaining Ag core and surface roughness of the Au shell were controlled by adjusting the chloroauric acid concentration. The porous cage exhibited excellent surface-enhanced Raman spectroscopy (SERS) activity, presumably due to a synergetic interaction between newly generated hot spots in the rough Au shell and the retained SERS activity of the Ag core. Using α-fetoprotein as a model analyte for immunoassay, the SERS signal had a wide linear range of 0.20 ng mL<sup>−1</sup> to 500.0 ng mL<sup>−1</sup> with a detection limit of 0.12 ng mL<sup>−1</sup>. Without the need of further signal amplification, the as-prepared Ag@Au bimetallic nanocages can be directly used for highly sensitive SERS assays of other biomarkers in biomedical research, diagnostics, etc. |
| first_indexed | 2024-04-11T11:58:12Z |
| format | Article |
| id | doaj.art-22b1a41405de4464967e2c06741ec048 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-11T11:58:12Z |
| publishDate | 2019-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-22b1a41405de4464967e2c06741ec0482022-12-22T04:25:01ZengMDPI AGSensors1424-82202019-03-01197155410.3390/s19071554s19071554Ag@Au Core–Shell Porous Nanocages with Outstanding SERS Activity for Highly Sensitive SERS ImmunoassayYaqi Huang0Dajie Lin1Mengting Li2Dewu Yin3Shun Wang4Jichang Wang5College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, ChinaCollege of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, ChinaCollege of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, ChinaCollege of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, ChinaCollege of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, ChinaCollege of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, ChinaA highly sensitive immunoassay of biomarkers has been achieved using 4-mercaptobenzoic acid-labeled Ag@Au core–shell porous nanocage tags and α-fetoprotein immuno-sensing chips. The Ag@Au porous nanocages were uniquely synthesized by using an Ag core as a self-sacrificial template and reducing agent, where the slow reaction process led to the formation of a porous Au layer. The size of the remaining Ag core and surface roughness of the Au shell were controlled by adjusting the chloroauric acid concentration. The porous cage exhibited excellent surface-enhanced Raman spectroscopy (SERS) activity, presumably due to a synergetic interaction between newly generated hot spots in the rough Au shell and the retained SERS activity of the Ag core. Using α-fetoprotein as a model analyte for immunoassay, the SERS signal had a wide linear range of 0.20 ng mL<sup>−1</sup> to 500.0 ng mL<sup>−1</sup> with a detection limit of 0.12 ng mL<sup>−1</sup>. Without the need of further signal amplification, the as-prepared Ag@Au bimetallic nanocages can be directly used for highly sensitive SERS assays of other biomarkers in biomedical research, diagnostics, etc.https://www.mdpi.com/1424-8220/19/7/1554surface-enhanced Raman spectroscopyimmunoassaybiomarkersAg core–Au shell porous nanocagesgalvanic replacement reaction |
| spellingShingle | Yaqi Huang Dajie Lin Mengting Li Dewu Yin Shun Wang Jichang Wang Ag@Au Core–Shell Porous Nanocages with Outstanding SERS Activity for Highly Sensitive SERS Immunoassay Sensors surface-enhanced Raman spectroscopy immunoassay biomarkers Ag core–Au shell porous nanocages galvanic replacement reaction |
| title | Ag@Au Core–Shell Porous Nanocages with Outstanding SERS Activity for Highly Sensitive SERS Immunoassay |
| title_full | Ag@Au Core–Shell Porous Nanocages with Outstanding SERS Activity for Highly Sensitive SERS Immunoassay |
| title_fullStr | Ag@Au Core–Shell Porous Nanocages with Outstanding SERS Activity for Highly Sensitive SERS Immunoassay |
| title_full_unstemmed | Ag@Au Core–Shell Porous Nanocages with Outstanding SERS Activity for Highly Sensitive SERS Immunoassay |
| title_short | Ag@Au Core–Shell Porous Nanocages with Outstanding SERS Activity for Highly Sensitive SERS Immunoassay |
| title_sort | ag au core shell porous nanocages with outstanding sers activity for highly sensitive sers immunoassay |
| topic | surface-enhanced Raman spectroscopy immunoassay biomarkers Ag core–Au shell porous nanocages galvanic replacement reaction |
| url | https://www.mdpi.com/1424-8220/19/7/1554 |
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