Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5031625 | Biosensors and Bioelectronics | 2017 | 34 Pages |
Abstract
We report citrate-capped platinum nanoparticles (Pt NPs) as oxidase mimetics for effectively catalyzing the oxidation of 3,3â²,5,5â²-tetramethylbenzidine (TMB), 2,2â²-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid), dopamine, and methylene blue in the presence of O2. To confirm oxidase-like activity of citrate-capped Pt NPs, their activity toward oxygen reduction reaction was studied using cyclic voltammetry and rotating ring-disk electrode method. The results obtained showed that Pt NP NPs can catalyze the oxidation of organic substrates to the colored product and the reduction of oxygen to water through a four-electron exchange process. Because the aggregation of Pt NPs can inhibit their oxidase-like activity and protamine can recognize heparin, we prepared the protamine-modified Pt NPs through direct adsorption on the surface of citrate-capped Pt NPs. The electrostatic attraction between heparin and protamine-stabilized Pt NPs induced nanoparticle aggregation, inhibiting their catalytic activity. Therefore, the lowest detectable heparin concentrations through UV-vis absorption and by the naked eye were estimated to be 0.3 and 60Â nM, respectively. Moreover, the proposed system enabled the determination of the therapeutic heparin concentration in a single drop of blood.
Related Topics
Physical Sciences and Engineering
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Analytical Chemistry
Authors
Jyun-Guo You, Yao-Wen Liu, Chi-Yu Lu, Wei-Lung Tseng, Cheng-Ju Yu,