Investigation on the morphology of precipitated chemicals from TE buffer on solid substrates

Buffer is often involved in the biological studies on a surface with the scanning probe microscopy and the remnant of the salts of buffer may affect the correct interpretation of the experimental results. However, the knowledge on the performance of chemicals of buffer on a substrate is still very poor. TE solution (Tris-HCl, NaCl, and ethylene diamine tetraacetic acid (EDTA)) is a widely used buffer in stocking biological molecules. Herein, we report the performance of the precipitated chemicals from TE solution on two typical substrates with several commonly used sample preparation methods. The results showed that the chemicals in TE solution could selforganize into parallel nanofilaments on hydrophobic highly oriented pyrolitic graphite (HOPG) surface by blotting the shortly incubated solution droplet from the substrate or by drying the diluted solution droplet naturally. In contrast, no such special structures were observed on hydrophilic mica using the same methods. By imaging in TE solutions, no special structures were found on either the HOPG or the mica. Moreover, the effects of the concentration of chemicals of TE buffer on the morphology of precipitated chemicals were also investigated.