Colorimetric detection of lysozyme based on its effect on the growth of gold nanoparticles induced by the reaction of chloroauric acid and hydroxylamine

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• 作者：Shaoxiong Wang ; Xiaochen Hu ; Lulu Tan ; Qing Liao ; Zhengbo Chen
• 关键词：Visual test ; Photometry ; Citrate capping ; Transmission electron microscopy ; Effect of particle size ; Egg white
• 刊名：Microchimica Acta
• 出版年：2016
• 出版时间：December 2016
• 年：2016
• 卷：183
• 期：12
• 页码：3135-3141
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Nanochemistry; Nanotechnology; Characterization and Evaluation of Materials; Analytical Chemistry; Microengineering;
• 出版者：Springer Vienna
• ISSN：1436-5073
• 卷排序：183

文摘

The authors have developed a straightforward colorimetric method for the rapid determination of lysozyme by using citrate-capped gold nanoparticles (AuNPs) with different particle sizes but without any further surface modification. It is found that AuNPs (15 nm i.d.) undergo aggregation in the presence of lysozyme owing to the high abundance of amino groups in lysozyme. Aggregation leads to a color change of the solution from red over purple to bluish-purple that can be detected visually or by photometry. The limit of detection is 20 nM. We further show that the use of AuNPs with 5 and 15 nm i.d. can improve the sensitivity of the assay compared to using bare AuNPs by adding HAuCl₄ and NH₂OH to the solution which induces the growth of AuNPs and leads to a smaller interparticle space between AuNPs. This gives rise to differently colored solutions, with color transitions from red to bluish-purple to colorless. The LODs are 0.1 nM for both the 5-nm and 15-nm AuNPs. Compared to the LOD when using a solution of 15-nm AuNPs and without chloroauric acid and hydroxylamine, the LOD (0.1 nM) is lower by a factor of 200. The method is sensitive, specific, and does not require sophisticated equipment. Its feasibility was demonstrated by analyzing lysozyme in samples of egg white.