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 (Cr2O3) 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 Cr2O3 nanoparticles. The performance of the Cr2O3 nanoparticles modified GCE for glucose sensing is found to be highly sensitive with the limits of detection 1.47 x 10(-4) M (LOD) and limits of quantification (LOQ) 4.91 x 10(-4) M. The linear range of glucose detection is determined to be 2.78 x 10(-4) M to 1.94 x 10(-3) M. The sensitivity of the modified GCE for glucose is determined to be 2.25 x 10(-2) A L mol(-1) cm(-2). From DPV, LOD corresponds to 1.08 x 10(-4) M while the LOQ is determined at 3.60 x 10(-4) M. The linear range of glucose detection by DPV is lower, 8.33 x 10(-4) M to 1.94 x 10(-3) M than that of CV. The glucose sensitivity also improves to 3.07 x 10(-3) A L mol(-1) cm(-2) by DPV technique. Finally, the Cr2O3 nanoparticles modified GCE is used successfully to determine the glucose contents in human urine samples.