A Study Of The Functional COF Electrode And Its Application For Pyocyanin Sensing In Aqueous Phase

Pseudomonas aeruginosa belongs to the genus of Pseudomonas,which often spreads in the water by carriers,such as medical wastewater,harbor,river,pool,especially in the swimming pools,and even drinking waters.Because of the improper management or disinfection.Pseudomonas aeruginosa infection can lead to a series of inflammation such as pneumonia,sepsis,or meningitis,which may lead to death in some severe cases.In the latest released by the health and Planning Commission in 2014,《The National Food Safety Standa--rd Packaging Drinking Water》（GB 19298-2014）clearly stipulates that Pseudomonas aeruginosa can not be detected in various packaging drinking water.Patients with airway infection caused by Pseudomonas aeruginosa are usually diagnosed by the culture of respiratory tract specimens,such as spontaneous sputum,induced sputum,or meningitis,which may lead to death in severe cases.These processes usually take more than 3 days to obtain the accurate results.In recent years,people have found some alternative diagnostic methods,like serology and polymerase chain reaction（PCR）,both of which have the potentials to detect Pseudomonas aeruginosa.However,PCR method needs expensive reagents and target specific primers,while serological method has the difficulty to detect early infection.Studies have shown that the corresponding bacteria can be detected indirectly by identifying the virulence factors secreted by bacteria.Pyocaynin is only secreted by Pseudomonas aeruginosa,which makes it a potential biomarker for diagnosis.In this study,we have designed a mesoporous Agnanoparticle（Ag NP）decorated covalent organic framework（COF）on an amino modified multi-walled carbon nanotube（NH₂-CNT）,which has been assembled through a simple approach.Then this composite was utilized as a new sensing material for fast detection of pyocyanin,the biomarker of P.aeruginosa infections.The synthesized material is characterized by Fourier-transform infrared spectroscopy（FTIR）,transmission electron microscopy（TEM）,cyclic voltammetry（CV）,and the differential pulse voltammetry（DPV）.From the results,the CNT/COF/Ag NPs composite showed a high specific surface area and good conductivity,when deposited on the glassy carbon electrode（GCE）.The CNT/COF/Ag NPs/GCE sensor offered excellent analytical performance to detect pyocyanin.The sensor offered a wide liner detection range from 0.3μM to 75μM of pyocyanin in phosphate-buffered saline（PBS）,and a low detection limit of1.18×10^-8M.Additionally,the outstanding recycling ability was also observed as more than100 reaction cycles for the reaction of pyocyanin and the CNT/COF/Ag NPs material.The recovery test was performed in PBS with a satisfactory recovery rate of 95%.