Co/Co-N@Nanoporous Carbon Derived from ZIF-67: A Highly Sensitive and Selective Electrochemical Dopamine Sensor

Co/Co-N nanoparticles incorporated nitrogen-doped nanoporous carbon (Co/Co-N@NPC) nanostructures were fabricated via pyrolysis of metal organic framework, ZIF-67, under argon atmosphere. The ZIF-67 derived Co/Co-N@NPC modified carbon paste electrode exhibited excellent performance during electroanalysis of dopamine, displaying two linear ranges; 10nM to 50M, and 50M-500M with sensitivity of 12.4 +/- 0.3A/M/cm(2) and11.69 +/- 0.06A/M/cm(2), respectively. The modified electrodes were observed to be highly selective towards dopamine even in presence of other interfering biomolecules such as ascorbic acid, glucose and uric acid. To the best of our knowledge, the sensing ability of Co/Co-N@NPC with a lower limit of detection as 6nM is the best compared to the previously reported cobalt mediated sensors for dopamine. Practical feasibility of the sensor was demonstrated in real sample analysis of dopamine measurement in human urine samples and dopamine hydrochloride injection samples.