Dual-color plasmonic enzyme-linked immunosorbent assay based on enzyme-mediated etching of Au nanoparticles.
Colorimetric enzyme-linked immunosorbent assay utilizing 3'-3-5'-5-tetramethylbenzidine(TMB) as the chromogenic substrate has been widely used in the hospital for the detection of all kinds of disease biomarkers. Herein, we demonstrate a strategy to change this single-color display into dual-color responses to improve the accuracy of visual inspection. Our investigation firstly reveals that oxidation state of 3'-3-5'-5-tetramethylbenzidine (TMB(2+)) can quantitatively etch gold nanoparticles. Therefore, the incorporation of gold nanoparticles into a commercial TMB-based ELISA kit could generate dual-color responses: the solution color varied gradually from wine red (absorption peak located at ~530 nm) to colorless, and then from colorless to yellow (absorption peak located at ~450 nm) with the increase amount of targets. These dual-color responses effectively improved the sensitivity as well as the accuracy of visual inspection. For example, the proposed dual-color plasmonic ELISA is demonstrated for the detection of prostate-specific antigen (PSA) in human serum with a visual limit of detection (LOD) as low as 0.0093 ng/mL.
Institute of Nanomedicine and Nanobiosensing; Ministry of Education Key Laboratory of Analysis and Detection Technology for Food Safety; College of Chemistry, Fuzhou University, Fuzhou, 350116, China.
Longhua
L
Guo
Institute of Nanomedicine and Nanobiosensing; Ministry of Education Key Laboratory of Analysis and Detection Technology for Food Safety; College of Chemistry, Fuzhou University, Fuzhou, 350116, China.
Shaohua
S
Xu
Institute of Nanomedicine and Nanobiosensing; Ministry of Education Key Laboratory of Analysis and Detection Technology for Food Safety; College of Chemistry, Fuzhou University, Fuzhou, 350116, China.
Xiaoming
X
Ma
Institute of Nanomedicine and Nanobiosensing; Ministry of Education Key Laboratory of Analysis and Detection Technology for Food Safety; College of Chemistry, Fuzhou University, Fuzhou, 350116, China.
Bin
B
Qiu
Institute of Nanomedicine and Nanobiosensing; Ministry of Education Key Laboratory of Analysis and Detection Technology for Food Safety; College of Chemistry, Fuzhou University, Fuzhou, 350116, China.
Zhenyu
Z
Lin
Institute of Nanomedicine and Nanobiosensing; Ministry of Education Key Laboratory of Analysis and Detection Technology for Food Safety; College of Chemistry, Fuzhou University, Fuzhou, 350116, China.
Guonan
G
Chen
D001560:Benzidines / Q000737:chemistry*; D015415:Biomarkers / Q000097:blood; D003124:Colorimetry; D004797:Enzyme-Linked Immunosorbent Assay; D006046:Gold / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry; D017430:Prostate-Specific Antigen / Q000097:blood*
D001560:Benzidines; D015415:Biomarkers; C021758:3,3',5,5'-tetramethylbenzidine; D006046:Gold; D017430:Prostate-Specific Antigen