Facile Synthesis of Water-Soluble WS2 Quantum Dots for Turn-On Fluorescent Measurement of Lipoic Acid

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• 作者：Yinghan Yan ; Cuiling Zhang ; Wei Gu ; Caiping Ding ; Xinchang Li ; Yuezhong Xian
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：June 9, 2016
• 年：2016
• 卷：120
• 期：22
• 页码：12170-12177
• 全文大小：528K
• 年卷期：0
• ISSN：1932-7455

文摘

A facile and eco-friendly approach for the synthesis of water-soluble WS₂ quantum dots (QDs) was developed via ultrasonication and a hydrothermal process from bulk WS₂. In this strategy, the dispersity of bulk WS₂ in aqueous phase was improved with the aid of a surfactant (hexadecyltrimethylammonium bromide, CTAB), which could shorten the exfoliation time and improve the exfoliation efficiency to form layered WS₂ nanosheets. Through hydrothermal treatment, the nanosheets were further scissored into QDs with high quality. The QDs show excellent features with narrow size distribution, good water solubility, and stable fluorescence. We find that the fluorescence of WS₂ QDs can be quenched by Fe³⁺ through photoinduced electron transfer, and a wide detection linear range for Fe³⁺ is acquired. It indicates that WS₂ QD can be used as a “turn-off” probe for Fe³⁺. In the presence of lipoic acid (LA), the fluorescence was recovered due to the stronger interaction between LA and Fe³⁺ than WS₂ QDs. A “turn-on” sensor for LA was developed with a linear range from 1 to 10 μM and a detection limit of 0.59 μM. The strategy might be suitable for the facile synthesis of other water-soluble transition metal dichalcogenide QDs. It is expected that the water-soluble QDs have great potential applications in biological system.