标题：Simple synthesis of uniformly small gold nanoparticles for sensitivity enhancement in colorimetric detection of Pb2+by improving nanoparticle reactivity and stability
作者：Xiahou, Yujiao ;Zhang, Peina ;Wang, Jin ;Huang, Lihui ;Xia, Haibing
作者机构：[Xiahou, Yujiao ;Zhang, Peina ;Wang, Jin ;Xia, Haibing ] State Key Laboratory of Crystal Materials, Shandong University, Jinan; 250100, China;[Huang, 更多
来源：Journal of Materials Chemistry C
摘要：We first synthesized high-quality gold nanoparticles (Au NPs) with size ranging from 5.5 to 17.8 nm in high yield via a robust, one-step seeded growth method using Tris-base (TB). It was found that the narrow distribution in size and shape of the as-prepared Au NPs was affected by reaction temperature and pH value of the reaction media. The sizes of these small Au NPs could be finely controlled by varying the gold precursor and/or seed amount according to an established relationship between the NP diameter and the particle number of the seeds (or the mass of the gold precursor in some cases). Due to their highly colloidal stability, TB-stabilized Au NPs (TB-Au NPs) could be directly used for the detection of Pb2+. Pb2+can be determined in a large linear range of 0.1 nM to 5 μM with a high determination coefficient, good repeatability (10 times at least) and high selectivity (1:200) by our 2-mercaptoethanol (2-ME)/S2O32--TB-AumNP sensors (m represents the size of Au NPs, m = 5.5, 10, and 15 nm). Moreover, the limit of detection (LOD) of the 2-ME/S2O32--TB-Au5.5NP sensor for Pb2+could be as low as 0.1 nM, which, to the best of our knowledge, is the lowest one obtained by a colorimetric method thus far. Furthermore, our 2-ME/S2O32--TB-Au5.5NP sensor could also detect Pb2+in real soil extracts with satisfactory recovery. Thus, the 2-ME/S2O32--TB-Au5.5NP sensor could be applied for the determination of Pb2+in real samples from complicated natural environments.
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