The aptabot: an inducibly affinity-switching, minimally invasivein vivocontrast agent

The ambitions of current neuroscience—understanding neurological disease progression and mapping the connectome—demonstrate a need for safe in vivo tools for creating intricate maps of brain circuitry. Present in vivo contrast agents are often limited by their specificity, uptake, resolvability, and/or clearance. We describe an aptamer-functionalized sensor for high-resolution imaging that can switch imaging targets by an induced multi-stage aptamer reaction. Included are synthetic methods as well as calculations of sensor efficacy based on known kinetics. Calculations show that 10 distinct targets may be imaged in a living brain at the submicron scale within 42 hours.