Combined in situ atomic force microscopy-infrared-attenuated total reflection spectroscopy

The combination of atomic force microscopy (AFM) with infrared attenuated total reflection (IR-ATR) spectroscopy for simultaneous spectroscopic evanescent field absorption and scanning probe measurements is presented. The capabilities of the combined setup are demonstrated by in situ AFM imaging of the dissolution process of urea in a cyclohexane/butanol solution with nanometer topographical resolution, while simultaneously recording the correlated bulk spectral changes by mid-infrared evanescent field absorption spectroscopy. Hence, surface modification processes such as dissolution or deposition can be simultaneously monitored by AFM imaging and IR spectroscopy in liquid environments, which has not been demonstrated to date. This combined technique will in the future enable kinetic studies on physical, chemical, and biological processes at a wide variety of surfaces providing chemical specificity via IR spectroscopy in addition to high-resolution imaging via AFM.