Colorimetric acetone sensor based on ionic liquid functionalized drug-mediated silver nanostructures

The current work reports the drug-mediated synthesis of silver nanoparticles (AgNPs) and their functionalization with ionic liquid (IL) for acetone determination. The rationale behind the selection of the Augmentin drug was the aromaticity in its structure and the functional groups attached. These properties are not only supposed to work in the synthesis of the nanoparticles but also enhance their electron density. The nanoparticles were further coated with 1-H-3-methylimidazolium acetate IL, having conductivity and aromaticity in their structure. The synthesized nanoparticles have been characterized by different techniques such as FTIR, XRD, SEM, and EDX. Colorimetric determination of acetone was done by using IL capped AgNPs with the assistance of NaCl solution and results were analyzed by UV-Vis spectrophotometry. Low-cost, stable eosin dye works as a substrate and is consumed resulting in a color change from brown to transparent. The IL capped AgNPs act as a reducing agent for the production of reduced radical form of acetone which act on the carboxylate moiety and bubble it out in the form of CO₂. Different parameters such as (concentrations, loading of nanoparticles, time and pH, etc.) were optimized to get the best results of the proposed sensor. The sensor shows a wide linear range of (1 ×10^-8-2.40 ×10^-6 M), low limit of detection 2.66 × 10^-9 M, and limit of quantification 8.86 × 10^-9 M with an R² value of 0.997. The proposed sensor has been successfully applied to diabetic patient's urine samples for acetone detection with a visible colorimetric change. It showed good sensitivity and selectivity towards acetone detection.