Dawson型多金属氧酸盐对南美白对虾中酪氨酸酶的催化作用

Catalysis of Dawson-Type Polyoxometalates on Tyrosinase in Penaeus vannamei

本文合成并表征P_(2)Mo_(17)Ni、P_(2)Mo_(17)Cr、P_(2)Mo_(17)Co和P_(2)Mo_(18)4种Dawson型多金属氧酸盐,通过循环伏安法研究不同多酸浓度和不同扫速下4种多酸水溶液的电化学性能,并在适宜条件下催化不同浓度的酪氨酸酶,研究多金属氧酸盐水溶液对酪氨酸酶的催化作用,研究果表明:4种化合物的氧化还原过程均属于扩散控制过程,对酪氨酸酶的电化学传感均显示出良好的稳定性,且响应电流与酪氨酸酶含量之间具有良好的线性关系,其中P_(2)Mo_(17)Ni的检测效果是4种化合物中最优的。通过计时安培曲线可知P_(2)Mo_(17)Ni对酪氨酸酶的最低检出限(S/N=3)可以达到0.4095 U/mL。将此方法应用于对虾中酪氨酸酶含量的检测,样品的回收率为98.0477%~99.5872%。此方法的选择性好,在多种干扰物质共存时,其检测结果几乎不受影响。这说明该修饰电极具有较高的准确性和稳定性。本研究为用此法检测南美白对虾及其它水产品中的酪氨酸酶含量,进而实现对它们的质量评价提供理论依据。

In this paper,four Dawson-type polyoxometalates of P_(2)Mo_(17)Ni,P_(2)Mo_(17)Cr,P_(2)Mo_(17)Co and P_(2)Mo_(18) were synthesized and characterized.The electrochemical properties of four polyoxometalates aqueous solutions at different polyoxometalates concentrations and different sweep rates were studied by cyclic voltammetry.And under suitable conditions to catalyze different concentrations of tyrosinase,the catalysis of polyoxometalates aqueous solutions on tyrosinase was studied.The results showed that the redox processes of the four compounds belong to the diffusion control process.The electrochemical sensing of tyrosinase all showed good stability,and there was a good linear relationship between the response current and tyrosinase content,and the detection effect of P_(2)Mo_(17)Ni was the best among the four compounds.The chronoamperometric curve shows that the lowest detection limit(S/N=3)of P_(2)Mo_(17)Ni for tyrosinase can reach 0.4095 U/mL.When this method is applied to the detection of tyrosinase content in shrimp,the sample recovery rate is 98.0477%-99.5872%,and the method has good selectivity.When multiple interfering substances coexist,the detection result is almost unaffected.It shows that the modified electrode has high accuracy and stability.This study provides a theoretical basis for the application of this method to detect the content of tyrosinase in Penaeus vannamei and other aquatic products,and to realize the quality evaluation of Penaeus vannamei and other aquatic products.