Ionic liquid as a moderator for improved sensing properties of TiO2 nanostructures for the detection of acetone biomarker in diabetes mellitus

In the present work, TiO2 nanoparticles have been synthesized by hydrothermal process and characterized using the techniques like FTIR, XRD, and SEM analysis. FTIR spectral analysis confirms the presence of Ti-O characteristic bond in TiO2 nanoparticles. The rutile phase of TiO2 nanoparticles having an average crystallite size of 26.8 nm was confirmed by XRD analysis. The SEM images indicate that the prepared nanoparticles are crystalline having a strong tendency to agglomerate. The 1-H-3-methylimidazolium acetate ionic liquid having aromaticity and conductive sites in its structure were synthesized using the simple neutralization method. A new colorimetric method was developed for acetone detection based on low-cost stable eosin dye as a substrate which reacts with acetone in the presence of ionic liquid coated TiO2 nanoparticles. The colored eosin dye (brown color) solution has been changed to the colorless product after reaction with acetone as analyzed by UV-Vis spectrophotometry. The optimization of different parameters (time, pH, temperature, concentrations, loading of nanoparticles, etc.) was conducted in order to get the best results of the proposed sensor. This sensor shows a wide linear range of 1.6 x 10(-6)-6.1 x 10(-5) mol L-1 and low limit of detection i.e. 2.7023 x 10(-5) mol L-1 with an R-2 value of 0.9995. The selectivity of the sensor was excellent when compared with the potential interfering substances. The response time was measured only 5 min for the proposed sensor. Moreover, the sensor was successfully applied to test acetone in the urine samples of diabetic patients having a blood sugar level in the range of 245-370 mg/dL. (C) 2019 Elsevier B.V. All rights reserved.