Colorimetric Probe Based on Destabilization of Silver Nanoparticles from Polysaccharide Matrix for Creatinine Detection

Colorimetric probes for creatinine detection using metal nanoparticles have attracted much attention due to their unique optical properties that could be observed by UV-vis spectrometer or naked eye. In this work, starch-stabilized silver nanoparticles (AgNPs) were adopted for creatine detection. AgNPs were synthesized by chemical technique. Soluble starch was used as a stabilizer. AgNPs could be stabilized in starch due to steric hindrance. Creatinine is a chemical that strongly bind with AgNPs. When creatinine was mixed with starch-stabilized AgNPs, the ligand-exchange reaction of creatinine and hydroxyl groups of starch occurred and AgNPs were destabilized from polysaccharide matrix of starch. After AgNPs were destabilized from starch, free AgNPs were aggregated due to Van der Waals attraction force. Extinction spectrum of AgNP colloidal solution showed a broad spectrum and the color of solution turned to orange. This system is a unique system because the this effect cannot observe from starch-stabilized gold nanoparticles (AuNPs). This work shows a high possibility to utilize AgNPs as a colorimetric probe for blood creatinine and urinary creatinine detections.