Data acquired during the microscale thermophoresis study on determination of pKa values of FITC. Data are accompanied with the results of laser induced fluorescent measurements on pH scale using the CE-LIF instrumentation. Finally data are accompanied with the result form the preliminary study: the recorded fluorescence signals for FITC with the MST instrument in response to the change in pH value: before turning on the IR laser (top), and at three different MST powers corresponding to different temperature gradients formed as a function of time (bottom).

Microscale thermophoresis (MST) is a rapidly developing bioanalytical technique used routinely for the examination of ligand-target affinity. It has never been used so far for the analysis of acid-base dissociation and determination of pKa constant. This work is the-proof-of-concept of this new idea. It demonstrates that the pKa values obtained from the thermophoretic data are consistent with the reference methods. As a result, the analytical potential and utility of the MST technology can become even greater, especially if the new detection system of thermophoretic movement will be developed in the future. Even now, taking into account the necessity to use fluorescence, the proposed method may be useful in many respects.