Electrochemical Detection of Nitrite in Medical and Environmental Samples with Oxidation Modified Carbon Fiber Electrode

The potential toxicity of nitrite to organisms and the environment makes it necessary to build a sensitive and accurate nitrite detection platform. The oxidation-modified carbon fiber electrode (OMCF) with a rougher surface and oxygen-containing functional groups is constructed by a simple high-temperature calcined treatment at 400 degrees C for 2 h for sensitive detection of nitrite. The amperometric test results exhibit that OMCF has two linear ranges of 1-1000 mu M and 1000-6000 mu M. Besides, its corresponding sensitivities are 988.57 and 668.51 mu A mM(-1) cm(-2), respectively. The low detection limit is 0.1 mu M. Importantly, the OMCF can be used to detect nitrite in a drop of water or medical samples. In addition, the OMCF with a length of 150 cm was successfully synthesized. The nine sections of the above OMCF are randomly selected to detect nitrite, which shows good reproducibility. Therefore, this work provides a facile method for preparing OMCFs with high sensitivity and wide linear range for the electrochemical detection of nitrite in urine and enables large-scale electrode production for medical applications.