To Örebro University

A number of emerging concepts for on-chip biotechnologies replace micro-fluidic flow by active, molecular-motor driven transport of filaments. Examples include applications in bio-simulation, diagnostics, and drug screening. Here we employ actomyosin molecular motors, embedded in nanostructures, as a platform for bio-simulation of the time evolution of motile objects in complex networks. A specific need for this type of application is detection of filaments at specific checkpoints in the device with high signal-to-noise ratio, for example to record the number and speed of filaments at a certain location in the device. To serve this need, we make use of fluorescence interference contrast (FLIC) at thin gold lines running perpendicular to nano-sized polymer resist channels that guide filament motion. We have demonstrated that it is possible to track single or multiple filaments passing over these gold lines, using either an enhanced or quenched fluorescence signal. We will discuss the fine-tuning of the device design, development of an algorithm for analyzing the optical readout signal from these detectors, and explo-ration of the error limits of detection. The results will help establish the viability of active, motor-driven on-chip applications which, among other advantages, offer substantial potential for miniaturization due to the absence of a need for pumps. The results also open for automatic read-out of velocity inhigh-throughput motility assays e.g. for drug discovery or fundamental bio-physical investigations. This work is supported by MONAD, an EU-FP7 collaborative effort.