A Simple and Efficient Colorimetric Detection of Creatinine Based on Citrate-Stabilized Gold Nanoparticles

Creatinine level is a crucial indicator in the clinical assessment and diagnosis of renal diseases, and achieving simple and accurate detection of urinary creatinine levels in resource-limited point-of-care settings is of great significance in the timely prevention and diagnosis of kidney diseases. As a popular zero-dimensional material, gold nanoparticles (AuNPs) exhibit intriguing optical properties and thus have become a promising material for many sensing detection applications. Here, we proposed a simple, efficient, and sensitive quantitative detection of creatinine by studying the relative absorbance (ΔA) of AuNPs in absence and presence of creatinine. The method relies on the aggregation of AuNPs via ligand-exchanged of citrate ions and creatinine on the surface of AuNPs to achieve colorimetric detection. With this assay, the limit of detection for creatinine was as low as 0.16 mM, and the dynamic detection range was 0.5 to 20 mM under optimized conditions. In our experiments, the specificity of the proposed method was investigated and successfully applied to detect creatinine in urine sample. It reveals that the proposed colorimetric protocol has demonstrated a high sensitivity and selectivity for creatinine, and has a potential practicability in clinical diagnostics.