EDTA Capped Silver Nanoparticles as a Probe for Highly Sensitive and Selective Colorimetric Sensing of Creatinine and Optimization using Response Surface Methodology-Box Behnken Design
Penulis/Author
INDAH MIFTAKHUL J (1); Prof. Drs. Roto, M.Eng, Ph.D. (2); Katsuaki Konishi (3); Prof. Drs. Dwi Siswanta, M.Eng., Ph.D. (4)
Tanggal/Date
26 2022
Kata Kunci/Keyword
Abstrak/Abstract
Creatinine detection is needed to help diagnose kidney function. Selective and sensitive creatinine detection methods are highly in demand now. Available methods have focused on the colorimetric method utilizing metallic nanoparticles. Better analytical performance is searched to meet the need through the functionalization of nanoparticles. We developed a creatinine colorimetric sensor based on EDTA-capped silver nanoparticles (AgNPs). The proposed method was optimized using response surface methodology (RSM) with Box-Behnken Design (BBD) model. It showed that medium pH had a very important role. The addition of creatinine to the colloidal EDTA-capped AgNPs induced the particle aggregation followed by a color change from yellow (with lambda max 398 nm) to dark blue (with lambda max 650 nm) within 1 min of reaction under alkaline media. The tautomerization of creatinine to its anionic amino species at alkaline pH, which cross-links the EDTA capped AgNPs via hydrogen bond networks with the negatively charged EDTA caps, is believed to be the aggregation mode. More importantly, the SPR absorbance ratio of A650/A398 was linearly correlated to the creatinine concentration under the optimized conditions in the range of 0.0–0.8 μM and 1.0–2.0 μM with an R2 value of 0.9934 and 0.9924, respectively. The limit of detection (LOD) was estimated to be 0.006 µM. The proposed method could offer simple, rapid, and inexpensive creatinine analysis for clinical diagnosis.
