College of Chemistry and Environmental Engineering, Shaoguan University, Shaoguan, 512005, Guangdong, China.
School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW, 2006, Australia.
Anal Bioanal Chem. 2018 Jul;410(18):4387-4395. doi: 10.1007/s00216-018-1094-7. Epub 2018 May 8.
A novel molecularly imprinted quartz crystal microbalance (QCM) sensor was successfully prepared for selective determination of sialic acid (SA) in human urine samples. To obtain the QCM sensor, we first modified the gold surface of the QCM chip by self-assembling of allylmercaptane to introduce polymerizable double bonds on the chip surface. Then, SA molecularly imprinted polymer (MIP) nanofilm was attached to the modified QCM chip surface. For comparison, we have also characterized the nonmodified and improved surfaces of the QCM sensor by using atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectroscopy. We then tested the selectivity and detection limit of the imprinted QCM sensor via a series of adsorption experiments. The results show a linear response in the range of 0.025-0.50 μmol L for sialic acid. Moreover, the limit of detection (LOD) of the prepared imprinted QCM sensor was found to be 1.0 nmol L for sialic acid, and high recovery values range from 87.6 to 108.5% with RSD < 8.7 (n = 5) for the spiked urine sample obtained. Overall, this work presents how a novel QCM sensor was developed and used to detect sialic acid in human urine samples. Graphical abstract Specific recognition of sialic acid by the MIP-QCM sensor system.
一种新型的分子印迹石英晶体微天平(QCM)传感器被成功制备用于选择性测定人尿液样品中的唾液酸(SA)。为了获得 QCM 传感器,我们首先通过烯丙基硫醇的自组装修饰 QCM 芯片的金表面,在芯片表面引入可聚合的双键。然后,将 SA 分子印迹聚合物(MIP)纳米薄膜附着在修饰后的 QCM 芯片表面。为了进行比较,我们还通过原子力显微镜(AFM)和傅里叶变换红外(FTIR)光谱对非修饰和改进后的 QCM 传感器表面进行了表征。然后,我们通过一系列吸附实验测试了印迹 QCM 传感器的选择性和检测限。结果表明,对于唾液酸,在 0.025-0.50 μmol·L 的范围内呈现出线性响应。此外,所制备的印迹 QCM 传感器的检测限(LOD)被发现对于唾液酸为 1.0 nmol·L,并且对于从人尿液样品中获得的加标样品,回收率值范围为 87.6%至 108.5%,相对标准偏差(RSD)<8.7(n=5)。总的来说,这项工作展示了如何开发和使用新型 QCM 传感器来检测人尿液样品中的唾液酸。