Surface Molecularly Imprinted Ordered Mesoporous Silica:Synthesis And Application In Sensor

Molecular imprinting technique (MIT) was used functional monomers by crosslinked polymerization in presence of the template, obtaining molecularly imprinted polymer (MIP) for selectively sensing template molecule. In this paper, MIP was prepared using tolazoline and dopamine as the template molecules and orderedly mesoporous silica as carrier, and was applied in sensor. Meanwhile, the synthesis methods of polymers, surface properties, adsorption characteristics, selectivity and the performance of sensor were studied. The main contents were as following:1. Preparation of a tolazoline sensor based on surface molecularly imprinting,ordered mesoporous silicaMolecularly imprinted polymer(MIP)for selectively sensing tolazoline, which was synthesized using tolazoline as the template and carboxyl modified mesoporous silica (SBA-15) as the supporter. Based on that, carbon paste electrode was prepared and the sensor was tested by cyclic voltametry. The result showed the sensor displayed a good linear range of4.0×10-7～5.0×10-6mol/L and5.0×10-6～1.0×10-4mol/L under optimized conditions,R was0.9717and0.9940respectively and the detected limit was1.6×10-8mol/L. The MIP sensor was used for urine sample and the recovery was in the range of97.5-104.2%. Additionally, the relative standard deviation (RSD) was from0.03%to0.21%.2. The preparation of sensor for dopamine based on surface molecularly imprinted ordered mesoporous silicaMolecularly imprinted polymer (MIP), which has specific selectivity to dopamine, was synthesized using dopamine as template and3-aminopropyltriethoxy-silane modified mesoporous silica as carrier. The MIP was used to fabricate a sensor for determination of dopamine. Its response to dopamine(DA) was evaluated by cyclic voltammetry. Under the optimized conditions, the sensor displayed a good linear range of1.0×10-7～2.0×10-6mol/L and2.0×10-6～1.0×10-4mol/L with a lower detection limit was1.3×10-9mol/L. The RSD (relative standard deviation) was0.9925and0.9969respectively. Moreover, the studied imprinted sensor exhibited high sensitivity and selectivity, and was successfully applied to the determination of dopamine in human blood.