Silver ion modulated CdS quantum dots for highly selective detection of trace Hg²⁺

详细信息    查看全文

• 作者：Yuwapon Uppa^a ; Sirinan Kulchat^a ; Kessarin Ngamdee^a ; Kaewklao Pradublai^a ; Thawatchai Tuntulani^d ; Wittaya Ngeontae^a ; ^b ; ^c ; ^{wittayange@kku.ac.th" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Quantum dots ; Chemical sensors ; Fluorescence sensors ; Fluorescence quenching ; Metallophilic interaction
• 刊名：Journal of Luminescence
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：178
• 期：Complete
• 页码：437-445
• 全文大小：2538 K

文摘

In the present work, water-soluble cysteamine capped-CdS quantum dots (Cys-CdS QDs) modulated with Ag⁺ were employed as fluorescence sensors for the determination of Hg²⁺ ion. The synthesized Cys-CdS QDs exhibit relatively weak fluorescence emission, however, the emission was enhanced exclusively in the presence of Ag⁺ compared to other metal ions. Moreover, the fluorescence intensity of the Ag⁺ modulated Cys-CdS QDs (Ag⁺@Cys-CdS QDs) was significantly quenched in the presence of trace amounts of Hg²⁺ due to high-affinity metallophilic interactions between Hg²⁺ and Ag⁺. Based on this specific interaction, good selectivity towards the detection of Hg²⁺ over other metal ions was achieved. To gain the best sensing performance, parameters affecting the Hg²⁺ detection sensitivity were studied and optimized in detail. Under the optimized conditions, the fluorescence intensity of Ag⁺@Cys-CdS QDs decreased linearly with Hg²⁺ concentration in the range of 0.1–3.5 μM, with a limit of detection of around 0.09 μM. The applicability of this sensor was demonstrated by the determination of Hg²⁺ in drinking water samples, corresponding well with results of cold-vapor atomic absorption spectrometry.