Abstract A highly selective and fast analytical assay using sodium gluconate -capped Ag nanoparticles (GA@AgNPs) was developed for the determination of creatinine by UV–Vis spectrophotometric detection. By adding creatinine to the GA@AgNPs solution, the extinction intensity of the surface plasmon resonance (SPR) band of the corresponding UV–Vis spectrum of GA@AgNPs at 393 nm reduced and meanwhile a new absorption peak appeared at 560 nm gradually with increasing creatinine concentratin. Induced aggregation of GA@AgNPs by creatinine, accompanied with color changes from yellow to red, can be directly observed by the nacked eye in five minutes. The extinction spectra ratio of A560/A393 was used for the colorimetric determination of creatinine. Effective parameters on the absorption intensity such as the sample pH, the type and buffer concentration, ionic strength and AgNPs concentration were optimized. Under the optimal conditions, a linear relationship between the SPR intensity ratio of A560/A393 values and creatinine concentrations is obtained over the range of 0.3–50 nM with a correlation coefficient of 0.9763 and a limit of detection of 0.2 nM. The relative standard deviation (RSD%) for five measurements of creatinine solution at 1 nM was 4.0%, exhibiting good repeatability. The results indicate that the developed probe can be successfully used for the determination of creatinine in serum and urine samples with satisfactory results.

中文翻译：

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葡萄糖酸钠包覆的银纳米粒子作为一种高灵敏度和选择性的比色探针，用于肉眼检测人血清和尿液中的肌酐

摘要 开发了一种使用葡萄糖酸钠封端的银纳米粒子 (GA@AgNPs) 的高选择性和快速分析方法，用于通过紫外-可见分光光度法检测肌酐。通过在 GA@AgNPs 溶液中加入肌酐，GA@AgNPs 相应的紫外-可见光谱在 393 nm 处的表面等离子体共振（SPR）带的消光强度降低，同时在 560 nm 处逐渐出现新的吸收峰，随着增加肌酐浓度。肌酐诱导的 GA@AgNPs 聚集，伴随着颜色从黄色变为红色，可以在五分钟内通过肉眼直接观察到。A560/A393的消光光谱比用于肌酐的比色测定。吸收强度的有效参数，例如样品 pH 值、类型和缓冲液浓度，离子强度和 AgNPs 浓度进行了优化。在最佳条件下，A560/A393 值的 SPR 强度比与肌酐浓度之间的线性关系在 0.3-50 nM 范围内获得，相关系数为 0.9763，检测限为 0.2 nM。1 nM 肌酐溶液五次测量的相对标准偏差 (RSD%) 为 4.0%，显示出良好的重复性。结果表明，所研制的探针可成功用于血清和尿样中肌酐的测定，结果令人满意。3–50 nM，相关系数为 0.9763，检测限为 0.2 nM。1 nM 肌酐溶液五次测量的相对标准偏差 (RSD%) 为 4.0%，显示出良好的重复性。结果表明，所研制的探针可成功用于血清和尿样中肌酐的测定，结果令人满意。3–50 nM，相关系数为 0.9763，检测限为 0.2 nM。1 nM 肌酐溶液五次测量的相对标准偏差 (RSD%) 为 4.0%，显示出良好的重复性。结果表明，所研制的探针可成功用于血清和尿样中肌酐的测定，结果令人满意。