Vibrational spectroscopy of single proteins

单个蛋白质分子的振动红外吸收在几个开尔文下被检测到，因为红外诱导的可见荧光的恢复与蛋白质被标记的染料。利用Alexa Fluor 660标记的牛血清白蛋白（BSA）分子，在波长6μm （1650cm-1）附近的r -螺旋结构的主链振动红外吸收光谱，验证了该红外吸收检测方法的灵敏度。除了测量振动红外吸收光谱外，可见荧光可以同时用于同一染料标记的单个蛋白质分子的成像。

Vibrational infrared absorption of a single protein molecule was detected at a few kelvins as infrared-induced recovery of visible fluorescence of a dye with which the protein was labeled. This sensitive method of detecting infrared absorption was demonstrated for a single bovine serum albumin (BSA) molecule labeled with Alexa Fluor 660 by determining the vibrational infrared absorption spectrum of the backbone vibrations of the R-helical structure in the wavelength region around 6μm (1650cm-1). In addition to measuring the vibrational infrared absorption spectrum, the visible fluorescence can be simultaneously used for imaging of the same dye-labeled single protein molecules.