Petra Janská, Nguyen To Quyen, Matěj Novák, Jitka Čejková, František Štěpánek

Chemotaxis is defined as the phenomenon in which living cells or multicellular organisms direct their movements according to certain chemicals in their environment. Such process is based on intra and intercellular signalling. Intelligent animals can find food by using the interaction between their senses (smell, sight, and sound) and their brains. Small organisms with no nose, eyes, ears, or brain find food by chemotaxis. Our aim is to design a synthetic system, where man-made objects will be able to sense the chemical gradients and perform “artificial chemotaxis”.

Our recent paper in Langmuir describes the chemotactic movement of decanol droplets in aqueous solutions of sodium decanoate in response to concentration gradients of NaCl. Key parameters of the chemotactic response, namely the induction time and the migration velocity, have been evaluated as function of the sodium decanoate concentration and the NaCl concentration gradient. The ability of the decanol droplets to migrate in concentration gradients has been demonstrated not only in a linear chemotactic assay but also in a topologically complex environment. Additionally, the ability to reverse the direction of movement repeatedly, to carry and release a chemically reactive cargo, to select a stronger concentration gradient from two options and to initiate chemotaxis by an external temperature stimulus, have been demonstrated.