Optomechanical Probes with Tailored Material and Shape Asymmetry Assembled Using DNA Origami

Optically trapped microscopic probes with precisely defined size, shape, and composition can be used for quantitative environmental sensing and for parametric investigation of fundamental physical phenomena at the classical-quantum boundary. The preparation of uniform ensembles of such probes is challenging, particularly considering probes with controlled shape or material asymmetries. We report a bottom-up strategy for fabricating the optomechanical probes using DNA nanotechnology. Specifically, we synthesize Janus-type colloidal heterodimers comprising two microspheres of different materials and sizes interconnected by 24HB DNA origami nanostructures. The interconnecting DNA origami scaffolds both facilitate the heterodimer assembly and enable their functionalization with other optical components. The utility of the fully assembled probes is then demonstrated by their 2D and 3D manipulation with optical tweezers. The versatility of the presented approach opens up the way toward fabricating novel custom-tailored probes for optomechanical experiments.