(813a) Towards a Biologically Inspired Nano-Factory for Molecular Assembly, Capture, Transport, and Characterization

Controlled manipulation of matter at the nanoscale is a common goal of nanotechnology and molecular diagnostics. A more ambitious goal is to build a nanofactory that incorporates functions such as molecular or nanoparticle assembly, capture, transport and characterization at the same time on the same platform. Various technologies have been developed to achieve these individual functionalities but an integrated platform combining all these functionalities is lacking. Here we describe a nano-engineered platform capable of building, manipulating and capturing multiple nanostructures in a massively parallel array. Nanostructures are formed by a two step hierarchical self assembly process. In the first step, fluorescent and magnetic nanoparticles are encapsulated in a self-assembled micellar structure. In the second level of self-assembly, the micellar structures are further complexed using protein-protein or complementary DNA interactions into higher order multifunctional nanoassemblies. The second level of assembly is shown to be concentration dependent and possesses fluorescent and magnetic properties of component nanoparticles. The magnetic functionality of the nanoassembly can be used to capture and transport aggregates on a magnetic microchip. Programmable traps can be created on the magnetic microchip, which consists of micro-patterned magnetic arrays and external electromagnets that control x-y and z directional magnetic fields. Transport of the nanoassemblies can be visualized in real time using the fluorescence functionality. The additive nature of fluorescence also helps characterize the nanostructures as they are being transported. We have shown assembly of quantum dots and superparamagnetic iron oxide nanoparticles in ampiphillic block copolymer micelles, followed by linker concentration dependent assembly in higher order structures; these structures are then transported along a nanoconveyor belt platform on magnetic microchip. We have demonstrated applications of this nanofactory in ultrasensitive detection and separation of protein, and DNA, in a diagnostic platform for detection and separation of circulating tumor cells. By inorporating molecular motors as molecular shuttles in the assembly we have achieved higher throughput leading to scale up. This platform can also be used for biophysical characterization of single molecules; as a proof of concept we have demonstrated preliminary experiments for determining bending strain values of microtubule-kinesin motor protein system.