Cadmium Sulfide Nanoparticles Decorated with Au Quantum Dots as Ultrasensitive Photoelectrochemical Sensor for Selective Detection of Copper(II) Ions
Cadmium Sulfide Nanoparticles Decorated with Au Quantum Dots as Ultrasensitive Photoelectrochemical Sensor for Selective Detection of Copper(II) Ions
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DOI：
10.1021/acs.jpcc.6b06929
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发表时间：
2016-10-06
影响因子：
3.7
通讯作者：
Pandikumar, Alagarsamy
中科院分区：
文献类型：
--
作者：
Ibrahim, Izwaharyanie;Lim, Hong Ngee;Pandikumar, Alagarsamy
铜的异常摄入具有显著的不良影响，并在生物体中显示出急性毒性。近年来，光电化学（PEC）法作为一种新型的Cu 2+离子传感器平台，因其具有灵敏度高、选择性好、成本低、选择准确等优点而备受关注。本工作采用分步水热法和原位化学法合成硫化镉纳米粒子（CdS NPs）修饰金量子点（Au QD），沿着具有显著的光电转换性能。负载在CdS纳米颗粒上的Au量子点的量对PEC性能有显著影响。具有1.0 mmol % Au QD的CdS NPs-Au QD-2表现出350.6 μ A cm（-2）的异常光电流密度，其分别比CdS NPs、CdS NPs-Au QD-1（0.75 mmol %）和CdS NPs-Au QD-3（1.25 mmol %）的光电流密度高3.7倍、2.2倍和2.0倍。飞秒瞬态吸收动力学的基态恢复表明，建立时间为243 fs的Au和268 fs的CdS，这被分配到光激发电子的冷却。对于CdS NPs-Au量子点，瞬态光谱由来自CdS的信号主导，没有来自Au的贡献。CdS-Au中不存在快速积累动态，表明光激发电子在冷却之前从CdS快速转移到Au。毫无疑问，CdS NPs-Au QDs-2光电极对Cu 2+检测的响应显示出在0.5-120 nM的线性范围内的最低检测限为6.73 nM。研究了CdS NPs-Au QDs-2对湖水和自来水中Cu ~（2+）离子的选择性，表明CdS NPs-Au QDs-2是一种很有前途的光电活性材料，可用于环境监测和分析。
Anomalous ingestion of copper has significant adverse effects and shows acute toxicity in living organisms. Recently, photoelectrochemical (PEC) method has attracted much attention as a platform for a Cu2+ ion sensor because of its high sensitivity, selectivity, low-cost, and accurate selection compared to other conventional methods. In this work, stepwise hydrothermal and in situ chemical approaches for synthesizing cadmium sulfide nanoparticles (CdS NPs) for decorating gold quantum dots (Au QDs) are presented, along with notable PEC performance. The amount of Au QDs loaded on the CdS NPs had a significant influence on the PEC performance. CdS NPs-Au QDs-2 with 1.0 mmol % Au QDs demonstrated an exceptional photocurrent density of 350.6 mu A cm(-2), which was 3.7-, 2.2-, and 2.0-fold higher than those of CdS NPs, CdS NPs-Au QDs-1 (0.75 mmol %), and CdS NPs-Au QDs-3 (1.25 mmol %), respectively. Femtosecond transient absorption dynamics of the ground state recovery showed a buildup time of 243 fs for Au and 268 fs for CdS, which were assigned to cooling of the photoexcited electrons. For CdS NPs-Au QDs, the transient spectrum was dominated by a signal from CdS with no contribution from Au. The fast buildup dynamic was absent in CdS-Au, indicating a rapid transfer of the photoexcited electrons from CdS to Au before cooling down. Unquestionably, the CdS NPs-Au QDs-2 photoelectrode response upon Cu2+ detection showed the lowest limit of detection of 6.73 nM in a linear range of 0.5-120 nM. The selectivity of CdS NPs-Au QDs-2 toward Cu2+ ions in lake and tap water was also studied, which suggested that CdS NPs-Au QDs-2 is promising as a photoactive material for PEC-based environmental monitoring and analysis.