In situ velocity control of gliding microtubules with temperature monitoring by fluorescence excitation on a patterned gold thin film

Abstract

Microtubule (MT) gliding on a kinesin-coated surface is a promising nanoactuator to manipulate nanomaterials in microfluidic environments. However, controllability of motors with respect to velocity, direction, and lifetime has been challenging for engineering purposes. Here, we used fluorescence excitation to control the MT velocity on a photolithographically patterned gold surface. The excitation wavelength was selected to match that used for the observation of MTs. Since a resistance temperature detector (RTD) was integrated on the assay substrate on which kinesin motors were coated, in situ temperature monitoring was implemented. Compared with the velocity of gliding MTs on the bare glass surface, the velocity increased by 1.8-fold on the gold-coated surface with the increase of temperature of 10.4 °C, which was caused by irradiance of 13.5 W · cm−2. We achieved repetitive velocity control, which was solely caused by the increase of temperature, i.e., irradiation energy. This key technology development enables reversible and localized velocity control of MT gliding, which can be easily integrated in nanosystems driven by kinesin motors.