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.
