Simultaneous analysis of molecular positions and coordination bond formations by frequency modulation atomic force microscopy in liquid

Abstract The simultaneous analysis of the molecular positions and their recognition functions of immobilized molecules presents a significant challenge. We investigated an analytical method using a Co–saloph complex as a model molecule. By employing frequency modulation atomic force microscopy with an amino-terminated tip, we examined the positions and their recognition functions at the single-molecular level. The results reveal that the specific coordination bond formations between the amino group on the tip and the Co–saloph complex is detectable as an increase in the dissipation signal, which occurs concurrently with the detection of the positions of the Co–saloph complexes.