Development of Aptamer-Based Non-labeling Methods

This chapter focuses on the non-labeling methods, including surface plasmon resonance (SPR), quartz crystal microbalance (QCM), isothermal titration calorimetry (ITC), and microscale thermophoresis (MST). It then introduces their principles and applications in analytical detection and binding affinity. The non-labeling methods discussed have been widely used to determine molecular interactions. Therefore, they were originally employed to measure the binding affinity between aptamers and targets. The greatest advantage of the non-labeling method is that there is no need to label the aptamer, and thus it can avoid making any change of the aptamer. As is known, compared with only the aptamer itself, the change of aptamer may cause some variations in its secondary or tertiary structure. And some of the variations may have a serious effect on the affinity and specificity of the aptamer. Once suitable non-labeling detection instruments, even handheld equipment, are developed, the non-labeling method will be more suitable for real-time monitoring.