| Nanomaterials have unique physical and chemical performances considering their nanoscale effect,which makes the nanomaterials-modified electrode playing crucial role for the improvement of the electrochemical analytical properties of dopamine?DA?sensors,such as the sensitivity and selectivity and so on.In this paper,three kinds of nanocomposites based on gold nanoparticles and polyaniline were prepared,and which were used to develop DA sensors.Correspondingly,three electrochemical sensing methods were established for the determination of DA.The research provided reference for enhancement of analytical properties of DA sensors,and provided useful detection method for clinical diagnosis of DA.The full paper included two chapters,and the main research contents were showed as follows:1.Nickel hydroxide nanowires with multicavities?m-Ni?OH?2?were synthesized based on an anion exchange strategy and chosen as supports of Au nanoparticles?AuNPs?for Au/m-Ni?OH?2.A DA sensor was fabricated based on Au/m-Ni?OH?2.The relationships between morphology,distribution and size of sensing interface nanomaterial and properties of sensor were investigated.And a new method was established towards DA detection.TEM observations revealed that AuNPs uniformly embedded in the cavities of m-Ni?OH?2,with a narrow size of 2 nm.Electrochemical investigations indicated that the linear range of the sensor was 0.45 to 1780?mol·L-1,with a sensitivity of 48.1?A(mmol·L-1)-11 cm-22 and a detection limit of 0.09?mol·L-1?S/N=3?.Without another surfactant,the AuNPs deposited on m-Ni?OH?2 were well-distributed with narrow size.Compared with similar sensors,linear range of the sensor was widened by one order of magnitude.2.AuNPs were anchored on the surface of Ag@C core-shell structure by in situ reduction process.A DA sensor was developed based on Ag@C/Au.The relationships between morphology and composition of electrode interface nanomaterial and properties of sensor were studied.And a new method was established towards DA analysis.SEM and TEM exhibited AuNPs were highly dispersed on the surface of Ag@C,without aggregation.Electrochemical investigations showed that the linear range of the sensor was 0.5-27.5?mol·L-1?27.5-277.5?mol·L-11 and 277.5-4278?mol·L-1,respectively,with the sensitivity of1615?482.9 and 61.9?A(mmol·L-1)-11 cm-2,and the detection limit of 0.2?mol·L-1?S/N=3?.In comparing with previous works,the sensor possessed the advantages of widening the linear range by two orders of magnitude and higher sensitivity.3.Sulfonated polyaniline?SPANI?was modified onto the surface of CNSs by chemical oxidative polymerization and sulfonation with one-step strategy.A DA sensor was constructed based on SPANI/CNSs.The relationship between composition of sensing interface nanomaterial and properties of sensor was explored.And a new method was established for DA detection.Electrochemical results indicated that the sensor can be used to determine DA with a linear range of 0.5 to 1780?mol·L-1,a sensitivity of 113.9?A(mmol·L-1)-11 cm-22 and a detection limit of 0.02?mol·L-1?S/N=3?.Compared with the sensors cited in the work,the sensor not only had excellent selectivity,but linear range of the sensor was increased by two orders of magnitude and the detection limit was reduced by nearly 2 orders of magnitude. |
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