| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 184570 | Electrochimica Acta | 2015 | 8 Pages |
•New aqueous dispersions of GO-[BMIM][PF6] water formed through simply tuning pH.•A new surfactant-free, water-processable CNT-GO-[BMIM][PF6] composite was also conveniently created by a simple sonication method at room temperature.•This composite displays excellent sensitivity and selectivity for the detection of DA with lowest detection limit.•This proposed method was successfully applied to detect dopamine in human serum and human urine samples.
Graphite oxide (GO) is a pH-dependent amphiphile with hydrophilic edges and a more hydrophobic basal plane. It was found that when the hydrophobic prototype ionic liquid (IL) of 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) was added into GO water, it experienced changes from coagulation to being redispersed in water phase by constantly turning its pH to alkali condition. Then new aqueous dispersions of GO-[BMIM][PF6] “water” formed after facile sonicate. The introduction of [BMIM][PF6] not only minimize the defects of poor electrical conductivity of GO and more interesting is that the carbon nanotube (CNT) can be highly dispersed in this GO-[BMIM][PF6] water through a simple and facile ultrasonic method at room temperature, forming a new composite of GO-[BMIM][PF6]-CNT with high dispersibility. This novel composite enhanced its electrochemical signal obviously in the measurement of dopamine (DA) in biological systems and exhibited a wider linear response ranging from 8.0 × 10−12–1.5 × 10−5 M. The detection limit of 3.0 × 10−12 M at a signal to-noise ratio of 3 was two orders of magnitude lower than that reported previously.
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