Abstract:
Nanocrystalline ZSM-5 was prepared using propyltriethoxysilane. Materials were characterized by a complementary combination of X-ray diffraction, nitrogen sorption, and scanning
electron microscopy. Transition-metal ion exchanged nanocrystalline ZSM-5-modified electrodes were constructed for the
electrocatalytic oxidation of glucose and methanol. A non-enzymatic electrochemical sensor based on a Ni2+-exchanged
nanocrystalline ZSM-5-modified electrode exhibits the highest
sensing ability, whereas the corresponding Cu2+-exchanged
electrode exhibits the highest current sensitivity for glucose
oxidation. Among the variety of electrodes modified with transition-metal ion exchanged nanocrystalline ZSM-5, the Ni2+-exchanged electrode exhibits high current sensitivity and sensing
ability in methanol oxidation. Electrocatalytic activity of conventional ZSM-5-modified electrodes was significantly low
compared to nanocrystalline ZSM-5-modified electrodes. Enhancement in the electrocatalytic activities of nanocrystalline
ZSM-5-modified electrodes can be correlated with the enhanced accessibility of glucose/methanol to M2+ active centers
in the nanocrystalline ZSM-5 owing to its large specific surface
area and intercrystalline mesopores. The sensor was applied directly to determine glucose concentration in adult human
blood serum, and the precision of the method was found to
be satisfactory. The non-enzymatic sensor exhibited excellent
reproducibility, repeatability, stability, and antifouling ability for
direct determination of glucose in human blood serum.
