对巯基苯硼酸修饰石英晶体微天平传感器用于测定唾液酸

摘要

A novel gold-coated quartz crystal microbalance ( QCM) sensor functionalized by 4-mercapto-phe-nylboronic acid(MPBA) was fabricated for monitoring of sialic acid. The surface property of QCM sensor was characterized by scanning electron microscope. The density of MPBA on the surface of QCM was calculated by the frequency change of QCM. The basic principle of the MPBA-modified sensor is that boronic acid can form reversible covalent bonds with analytes containing cis-1 ,2-diols groups. The results show a linear response in the range of 0. 50-5. 0 mmol/L of sialic acid. The detection limit was 0. 15 mmol/L( n = 11) for sialic acid and high recovery of 101. 7 for the spiked artificial urine sample was obtained.%硼酸与二醇的脱水缩合反应已被广泛用于检测或富集顺式邻位多羟基化合物.本文以对巯基苯硼酸(MPBA)自组装修饰石英晶体微天平(QCM)芯片,基于硼酸根对唾液酸的特殊反应,建立了检测唾液酸(SA)的新方法.采用扫描电子显微镜表征了对巯基苯硼酸对石英晶体微天平的功能化修饰过程,并研究了溶液pH值对芯片表面亲和力的影响.实验结果表明,随着pH值的降低,修饰芯片对唾液酸的结合能力增强,而对参照物葡萄糖的结合能力则降低.在pH=4.0的条件下,该传感器在0.50 ～ 5.0 mmol/L范围内对唾液酸有很好的线性响应,相关系数为0.9950,检出限为0.15 mmol/L.此传感器提供了一种简易的唾液酸检测方法,为实际样品的测定奠定了基础.