Perpustakaan Digital ITB

Metal/nitrogen/carbon (M/N/C, M = Co orFe) nanomaterials have been demonstrated to catalyze oxygenreduction reaction (ORR) with implication in fuel cell studies;however, their potential application as sensing materials for invivo monitoring of oxygen (O2) in the central nervous systemhas never been reported. This study reports afirstdemonstration that M/N/C nanomaterials can be used assensing materials to form an electrochemical assay for in vivoO2monitoring. To demonstrate this application, the M/N/Cnanocomposites prepared by pyrolysis of zeolitic imidazolateframework (ZIF-67) are used as an example and iselectrophoretically deposited onto carbonfiber microelectr-odes (CFEs) to catalyze a four-electron reduction of O2without producing cell-toxic hydrogen peroxide intermediate. The M/N/C-sheathed CFEs have high catalytic performancetoward ORR in a neutral solution, selectivity toward O2sensing in the presence of ascorbic acid (AA), dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC), uric acid (UA), and 5-hydroxytryptamine (5-HT) at their physiological levels in ratbrain, and capability to real-time monitor O2fluctuation during respiring gases. This study offers a new electrochemicalapproach to in vivo O2monitoring with nonplatinum catalyst for ORR