Preparation Of Electrochemical Biosensor Based On Biological Fuel Cell And Its Selective Determination Of PFOS

Perfluorooctane sulfonate (PFOS), one of the most representative perfluoroalkyl acidic compounds, has been widely used in industrials, and thus been emitted in various ambient media. The PFOS in ambient media could threaten human health, as it is toxic to many organs in different ways. Nowadays, the conventional methods for PFOS detection is High Performance Liquid Chromatography-Mass Spectrometry and Gas Chromatograph-Mass Spectrometer, which is not suitable for fast detection of PFOS in outdoors or polluted scenes, because the procedures of these methods are tedious, and the equipment are expensive. Therefore, concerning the complexity of the environmental samples and the requirement of fast detection, it is meaningful to develop a method for PFOS detection that is expected to be low cost, fast and efficient, and high sensitive and selective.Electrochemical biosensor has the advantages of high sensitivity and selectivity, and fast and efficiency. Besides, biofuel cell which could utilize the ambient biofuel efficiently, is able to degrade pollutants and give rise to clean energy simultaneously. Moreover, carbon nanotubes has the large specific surface areas and excellent property for electron transfer. Based on the above three aspects, firstly, enzyme was covalently immobilized on the surface of glassy carbon electrode (GCE) which had been modified with manomaterials. Then, we constructed a unipolar biofuel-based electrochemical sensor, which was high sensitive and selective to PFOS in aqueous phase. Finally, the sensor was evaluated to detect the PFOS in aqueous phase by differential open circuit potential-time scanning.The electrodes of the sensor were characterized by various methods, and the actual water samples were detected. The results confirmed that the carbon nanotubes played important role in electron transfer, and the obtained sensor was capable of detecting PFOS selectively. Under the optimal condition, the linear range for PFOS detection was5-500nmol/L with a detectable limitation of1.6nmol/L. The maximum output power for the biofuel cell was1.94μW, and the density of the maximum power was27.5μW/cm2. The sensor was quite stable, since its open circuit voltage was still96.7%of the initial voltage after8hours of continuous work. Besides, the electrode of the sensor showed high selectivity to PFOS, because the open circuit voltage response for PFOS is46,30, and40times higher than that for perfluorooctanoic acid ammonium, sodium3-nitrobenzenesulfonate, and sodium lauryl benzenesulfate, respectively.Based on the electrochemical biosensor, biofuel cell and carbon nanotubes, this work developed a novel method for fast determination of the PFOS concentration in water, which may have the potential applications in the high sensitive and selective detection of PFOS in the polluted scenes, such as polluted water.