Enzyme-Free Amplification Strategy for Biosensing Using Fe3+–Poly(glutamic acid) Coordination Chemistry
| Autor: | Hongtao Lei, Yunlei Xianyu, Ning Lu, Meng-Xia Xie, Xiangfeng Wang, Jing Wu, Zhitao Zhao, Yiping Chen, Dehua Hu |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
inorganic chemicals
chemistry.chemical_classification Nanostructure medicine.diagnostic_test Metal ions in aqueous solution Polyglutamic acid Nanoparticle 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Combinatorial chemistry 0104 chemical sciences Analytical Chemistry Coordination complex chemistry.chemical_compound chemistry Immunoassay medicine Polystyrene 0210 nano-technology Biosensor |
| Zdroj: | Analytical Chemistry. 90:4725-4732 |
| ISSN: | 1520-6882 0003-2700 |
| Popis: | In this work, we outline a signal amplification strategy using the coordination chemistry between Fe3+ and poly(glutamic acid) (PGA) for biosensing applications. The theoretical calculation based on density functional theory shows that PGA has a much higher binding affinity with Fe3+ than the other metal ions. Guided by this rationale, we prepare a PGA-mediated signal probe through conjugating PGA onto polystyrene (PS) nanoparticles to form a brushlike nanostructure for Fe3+ coordination. This PGA-PS brush (PPB) has a large loading capacity of Fe3+ with a number of 1.92 × 108 Fe atoms per nanoparticle that greatly amplifies the signals for assays in an enzyme-free way. Combined with ferrozine coloration-based readout, this PPB-mediated amplification is further applied for the enzyme-free immunoassay that shows an ultrahigh sensitivity for detection of microcystins-LR (12 pg/mL), a 5-fold enhancement compared with that of traditional enzyme-linked immunosorbent assay (ELISA) (60 pg/mL). In addition, the good stability, rapid response, and long shelf life make this enzyme-free amplification strategy a promising platform for point-of-care biosensing applications. |
| Databáze: | OpenAIRE |
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