Cu2O/UiO-66/Ag2CO3 NANO STRUCTURED MATERIAL AS NONENZYMATIC ELECTROCHEMICAL SENSOR FOR THE DETERMINATION OF GLUCOSE

Abstract

Zirconium based Metal organic framework (UiO-66), cuprous oxide (Cu2O), silver carbonate (Ag2CO3), binary system Cu2O/UiO-66, UiO-66/Ag2CO3 and the ternary Cu2O/UiO-66/Ag2CO3 nanocomposites were synthesized by sol-gel and co-precipitation method to employ GCE modified by these materials as non-enzymatic electrochemical glucose sensors. The crystanility, structure and composition of the as prepared nanocomposites were characterized using X-ray diffraction) patterns, Fourier transform infrared spectroscopy, and ultra-violet spectroscopy. The electrochemical properties of different modified electrodes on the other hand were investigated by employing cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The result reveals ternary system has lowest particle size than others. The result confirms the formation the expected nanomaterials were narrow band gap with good interaction. The modified UiO-66, Cu2O/UiO-66, UiO-66/Ag2CO3 and Cu2O/UiO-66/Ag2CO3 were characterized using electrochemical techniques. The result demonstrates that ternary system nanocomposite gave a high peak current response and low charge transfer resistance with respect to others. This is most probably due to the synergetic effect of the catalytic properties of Cu2O and high surface area of the UiO-66. The redox potential of potassium ferrocynide was near to that of its ideal value indicating the reversibility of the process. The proposed sensor was optimized to identify appropriate experimental condition for glucose detection. The optimum condition was found to be pH 13, detection potential 0.6 V and concentration 0.1 M. Under this condition the sensor was tested for the detection of glucose in standard solution and exhibits good linearity 0.02-0.12µmol L−1 , sensitivity of 2890 A mM-1 cm-2 and detection limits 6.61x10-5 molL-1 (3σ/N), high selectivity, good stability and reproducibility. The sensor was also applied for blood glucose determination in human blood serum specimen collected from Hiwot Fana Specialized University Hospital and the concentration was found to be 2.99-4.99 mM. The result shows that Cu2O/UiO66/Ag2CO3 can be a potential candidate for routine analysis of glucose.