Ebner Andreas, Wildling Linda, Zhu Rong, Rankl Christian, Haselgrübler Thomas, Hinterdorfer Peter, Gruber Hermann J
University of Linz, Institute of Biophysics, Altenberger Str. 69, A-4040, Linz, Austria.
Top Curr Chem. 2008;285:29-76. doi: 10.1007/128_2007_24.
The measuring tip of a force microscope can be converted into a monomolecular sensorif one or few "ligand" molecules are attached to the apex of the tip while maintainingligand function. Functionalized tips are used to study fine details of receptor-ligand interactionby force spectroscopy or to map cognate "receptor" molecules on the sample surface. Thereceptor (or target) molecules can be present on the surface of a biological specimen; alternatively,soluble target molecules must be immobilized on ultraflat supports. This review describes the methodsof tip functionalization, as well as target molecule immobilization. Silicon nitride tips, siliconchips, and mica have usually been functionalized in three steps: (1) aminofunctionalization,(2) crosslinker attachment, and (3) ligand/receptor coupling, whereby numerous crosslinkersare available to couple widely different ligand molecules. Gold-covered tips and/or supports haveusually been coated with a self-assembled monolayer, on top of which the ligand/receptor moleculehas been coupled either directly or via a crosslinker molecule. Apart from these general strategies,many simplified methods have been used for tip and/or support functionalization, even single-stepmethods such as adsorption or chemisorption being very efficient under suitable circumstances. Allmethods are described with the same explicitness and critical parameters are discussed. In conclusion,this review should help to find suitable methods for specific problems of tip and support functionalization.
如果在力显微镜的测量尖端附着一个或几个“配体”分子并保持配体功能，那么该测量尖端就能转化为单分子传感器。功能化的尖端可用于通过力谱研究受体 - 配体相互作用的精细细节，或在样品表面绘制同源“受体”分子图谱。受体（或靶标）分子可以存在于生物样本的表面；或者，可溶性靶标分子必须固定在超平的支持物上。本综述描述了尖端功能化以及靶标分子固定的方法。氮化硅尖端、硅芯片和云母通常通过三个步骤进行功能化：（1）氨基功能化，（2）交联剂附着，以及（3）配体/受体偶联，由此有多种交联剂可用于偶联广泛不同的配体分子。金覆盖的尖端和/或支持物通常涂有自组装单分子层，在其之上配体/受体分子已直接或通过交联剂分子进行偶联。除了这些一般策略外，许多简化方法已用于尖端和/或支持物功能化，甚至单步方法如吸附或化学吸附在合适的情况下也非常有效。所有方法都以相同的明确性进行描述，并讨论了关键参数。总之，本综述应有助于为尖端和支持物功能化的特定问题找到合适的方法。
