Study On The Detection Of β-Agonists Based On Molecularly Imprinted Sol-gel Electrochemical Sensor

Molecularly imprinted polymers (MIPs) have a lot of advantages, such as excellent specific recognition function, unique physical, chemical and mechanical features, resistance to severe environment, long service life, good stability, and can be recycled, and so on. For this reason, MIPs could be widely used in the separation, detection and molecular catalysis and other fields. The use of biosensor has difficulties in preservation, proper conditions and limited object, but MIPs sensor overcomes the above drawbacks, and becomes one of the research hotspots in electrochemical sensor. Comparing with other techniques, the advantage of sol-gel is that the thickness and the surface area of the polymer layer can be monitored and regulated easily. In recent years, nanoparticles have attracted great attention in the electrochemical research as a modified material owing to its low mass density, large specific surface area, good stability and electrical conductivity,In this paper, the MIPs/nanoparticles electrodes were developed by sol-gel polymerization with single-wall carbon nanotube via taking β-agonists as template molecule, respectively. The imprinted sensors showed high recognition ability and affinity, and were successfully applied to the determination of P-agonists in real samples.In this thesis, the main contents of this thesis are summarized as follow:(1) Electrochemical sensor based on a carbon nanotube-modified imprinted SPU sol-gel for selective and sensitive determination of β-agonistsA molecularly imprinted sol-gel/SWNTs modified electrode was developed via taking β-agonists as template molecule, and SPU as functional monomer. The characterization of molecularly imprinted SWNTs modified electrode was investigated via scanning electron microscope (SEM) and electrochemical methods. The electrochemical behaviors of P-agonists at the molecularly imprinted SWNTs modified electrode, the optimal experimental conditions, incubation time, selectivity, stability and repeatability were investigated. Under the optimal experimental conditions, the proposed sensor exhibit a wide linear range and low detection limit for β-agonists. Besides, the optimized sensor displays high sensitivity and excellent selectivity for the β-agonists as shown for their determination in human serum samples.(2) Electrochemical sensor based on a carbon nanotube-modified imprinted ATO sol-gel for selective and sensitive determination of β-agonistsA molecularly imprinted SWNTs modified electrode was fabricated by taking P-agonists and ATO/silica sol as template molecule and functional monomer, respectively. Scanning electron microscope (SEM) was employed to investigate the surface morphologies and electrochemical properties of the imprinted layer. The determination was carried out by measuring the cycle voltametry response. Under the optimal experimental conditions, the current response of the imprinted sensor was linear to the concentration of salbutamol in constant range and the detection limit was low. The imprinted electrochemical sensor was successfully applied to the determination of β-agonists in human serum samples. The presence of some analogues didn’t interrupt the determination of β-agonists. The sensor has potential application prospect.