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Label-free Detection of 3-nitro-l-tyrosine With Nickel-Doped Graphene Localized Surface Plasmon Resonance Biosensor

Siu Pang Ng, Guangyu Qiu, Ning Ding, Xiaoqing Lu, Chi-Man Lawrence Wu

Biosens Bioelectron. 2017 Mar 15;89(Pt 1):468-476.

PMID: 27085521

Abstract:

3-nitro-l-tyrosine (3-NT) is believed to be a biomarker of neurodegenerative diseases and metal doped graphene possess exceptionally high binding energy of 3-NT with metal-nitro chemisorption. Here we report a novel label-free detection scheme of 3-NT via nickel-doped graphene (NDG) as the functionalized receptor on our phase detecting localized surface plasmon resonance (LSPR) biosensor. When compared with reported 3-NT immunoassay with enzyme-linked immunosorbent assay (ELISA), our NDG-LSPR platform offers two advantages i.e. 1) label-free and 2) capture of 3-NT by direct chemisorption. Our limit of detection for 3-NT in PBS was found to be 0.13pg/ml and the linear dynamic range of response was from 0.5pg/ml to 1ng/ml, i.e. four orders of magnitude. The specificity of our NDG receptor to 3-NT was also verified with l-tyrosine of equivalent concentrations in PBS and diluted human serum, for which the NDG receptor shows negligible responses. In addition, the adsorption of 3-NT and l-tyrosine to the NDG receptor were also investigated by atomic force microscopy and further verified by surface enhanced Raman spectroscopy. Therefore, our NDG-LSPR biosensor competes favorably against ELISA and we believe it should be an attractive and economical solution to early diagnostic of 3-NT related disorders for clinical applications.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP621443 3-Nitro-L-tyrosine 3-Nitro-L-tyrosine 621-44-3 Price
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