【摘要】 该文以硼氢化钠为还原剂、海藻酸钠（SA）为稳定剂，通过一步法制备了海藻酸钠-银纳米粒功能探针（SA-Ag NPs）。采用透射电子显微镜（TEM）、动态光散射（DLS）、红外光谱（FT-IR）、X-射线能量散射谱（EDS）、紫外-可见吸收光谱（UV-Vis）对制备的SA-Ag NPs的形貌和光学特性进行表征。结果显示，SA可以增强Ag NPs的分散性和稳定性，提高其400 nm波长处的表面等离子体共振吸收。当尿酸（UA）存在时，UA与SA分子发生配体交换导致Ag NPs聚集，并在530 nm处产生吸收峰，同时溶液颜色由亮黄色变为酒红色。基于此构建了一种比率型的UA比色法检测体系，并实现了UA的可视化分析。优化条件下，在1.67×10^-5～1.67×10^-3 mol/L浓度范围内，检测体系的吸光度比值(A_{530 nm}/A_{400 nm})与UA浓度的对数呈良好的线性关系（r=0.992），检出限（LOD）为14.9μmol/L。尿液中常见的无机离子及其他生物小分子如葡萄糖、抗坏血酸、尿素、肌酐等不干扰尿酸测定。尿样的加标回收率为92.7%～109%，相对标准偏差小于1.0%。该比色探针环保、制备简单、特异性强、稳定性好，有望为尿酸临床相关疾病（如高尿酸血症、痛风、肾病、心血管疾病等）的生化诊断提供一种新的检测方法。更多还原

【Abstract】 A ratiometric nanoprobe based on sodium alginate（SA）-stabilized silver nanoparticles（Ag NPs） was constructed for the colorimetric detection of uric acid（UA） in urine samples in this paper.The SA functionalized AgNPs nanoprobe was prepared by a facile one-step synthesis method with NaBH4 as reducer and SA as stabilizer.Furthermore,the morphological and spectral properties of the as-obtained nanoprobe were carefully characterized by transmission electron microscopy（TEM）,dynamic light scattering（DLS）,Fourier transform infrared spectroscopy（FT-IR）,X-ray energy dispersive spectroscopy（EDS）,and ultraviolet-visible spectroscopy（UV-Vis）.It is found that SA could improve the dispersity and stability of AgNPs,and increase the surface plasma resonance at 400 nm.In the presence of UA,the nanoprobe could be induced to agglomerate via ligand exchange between the target and SA molecules,giving rise to a 530 nm absorption peak and leading to the color change from bright yellow to wine red.Consequently,a colorimetry-based ratiometric sensing strategy could be established.Meanwhile,the color evolution upon the exposure to UA offers the possibility for visualizing analysis of UA.In the optimized conditions,this designed nanoprobe yields a linear response to UA in the concentration range of 1.67 × 10^-5-1.67 × 10^-3 mol/L（r = 0.992）,with a limit of detection（LOD） of 14.9 μmol/L.Moreover,the commonly coexisting inorganic ions and small biomolecules（e.g.,glucose,ascorbic acid,urea and creatinine） in urine samples cannot produce interference to UA detection,and the spiked recoveries for real urine samples ranged from 92.7% to 109% with relative standard deviations less than 1.0%.With the advantages of ecofriendly and simple preparation,as well as favorable specificity and stability,the present nanoprobe could provide a novel detection method for aiding diagnosis of UA-related clinical diseases such as hyperuricemia,gout,renal and cardiovascular diseases.更多还原