Ionic liquid assisted synthesis of chromium oxide (Cr2O3) nanoparticles and their application in glucose sensing

Here we report a solvothermal–hydrothermal based method for the synthesis of spherical chromium oxide (Cr 2 O 3 ) nanoparticles in 1-butyl-3-methyl imidazolium bromide ([BMIM] + [Br] − ) and water (1:1 V/V) as a solvent. Electrochemical glucose sensing was performed by using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The working electrode, glassy carbon electrode (GCE) was modified by using the synthesized Cr 2 O 3 nanoparticles. The performance of the Cr 2 O 3 nanoparticles modified GCE for glucose sensing is found to be highly sensitive with the limits of detection 1.47 × 10 −4 M (LOD) and limits of quantification (LOQ) 4.91 × 10 −4 M. The linear range of glucose detection is determined to be 2.78 × 10 −4 M to 1.94 × 10 −3 M. The sensitivity of the modified GCE for glucose is determined to be 2.25 × 10 −2 A L mol −1 cm −2 . From DPV, LOD corresponds to 1.08 × 10 −4 M while the LOQ is determined at 3.60 × 10 −4 M. The linear range of glucose detection by DPV is lower, 8.33 × 10 −4 M to 1.94 × 10 −3 M than that of CV. The glucose sensitivity also improves to 3.07 × 10 −3 A L mol −1 cm −2 by DPV technique. Finally, the Cr 2 O 3 nanoparticles modified GCE is used successfully to determine the glucose contents in human urine samples.