Department of Mechanical and Aerospace Engineering, University of Californiam, 420 Westwood Plz., Engineering IV, Los Angeles, CA 90095-1597, USA.
Biosens Bioelectron. 2010 Oct 15;26(2):602-7. doi: 10.1016/j.bios.2010.07.021. Epub 2010 Jul 16.
We demonstrated a novel method for the formation of alloy nano-islands on carbon nanotube (CNT). The two metal layers (Pt, Au) were sputtered on CNTs and the intense pulsed light (IPL) was irradiated on the metal layers. The absorbed light provides enough energy for the diffusion mixing between Pt and Au, forming Pt-Au alloy phase. While the alloy is being formed by the IPL irradiation, the metal layers are broken into nano-islands on CNT due to the surface energy minimization between the metal layers and CNT. The surface characterizations of the Pt-Au/CNT were performed with X-ray diffraction, scanning electron microscope, and energy-dispersive X-ray spectroscopy. Different compositions of alloy nanoparticles were obtained by adjusting the deposition thicknesses of Pt and Au on CNT. Pt50Au50/CNT electrode showed the highest glucose oxidation current peak among Pt, Pt70Au30, Pt50Au50, Pt30Au70, and Au/CNT electrodes while the electroactive surface areas of them are kept to be similar (average surface area=7.00 cm2, coefficient of variation=0.06). The amperometric response of Pt50Au50/CNT electrode to the glucose concentrations showed a wide linear range up to 24.44 mM with a high detection sensitivity of 10.71 μA mM(-1) cm(-2). Reproducibility and long-term stability of the Pt-Au/CNT electrode were also proven in the experiments.
我们展示了一种在碳纳米管（CNT）上形成合金纳米岛的新方法。将两层金属（Pt、Au）溅射在 CNT 上，然后用强脉冲光（IPL）照射金属层。吸收的光为 Pt 和 Au 之间的扩散混合提供了足够的能量，形成 Pt-Au 合金相。在 IPL 照射下形成合金时，由于金属层和 CNT 之间的表面能最小化，金属层在 CNT 上破裂成纳米岛。使用 X 射线衍射、扫描电子显微镜和能谱对 Pt-Au/CNT 的表面特性进行了表征。通过调整 CNT 上 Pt 和 Au 的沉积厚度，可以获得不同成分的合金纳米颗粒。Pt50Au50/CNT 电极在 Pt、Pt70Au30、Pt50Au50、Pt30Au70 和 Au/CNT 电极中表现出最高的葡萄糖氧化电流峰，而它们的电化学活性表面积保持相似（平均表面积=7.00 cm2，变异系数=0.06）。Pt50Au50/CNT 电极对葡萄糖浓度的电流响应呈现出宽的线性范围，可达 24.44 mM，检测灵敏度高达 10.71 μA mM(-1) cm(-2)。Pt-Au/CNT 电极的重现性和长期稳定性也在实验中得到了证明。
