Electric field directed fabrication of biosensor devices form biomolecule derivatized nanoparticles

An electronic microarray has been used to carry out directed self-assembly of higher order 3D structures from Biotin/Streptavidin and DNA derivatized nanoparticles. Structures with more than forty layers of alternating biotin and streptavidin and DNA nanoparticles were fabricated using a 400 site CMOS microarray system. In this process, reconfigurable electric fields produced by the microarray device have been used to rapidly transport, concentrate and accelerate the binding of 40 and 200 nanometer biotin, streptavidin, DNA and peroxidase derivatized nanoparticles to selected sites on the microarray. The nanoparticle layering process takes less than one minute per layer (10-20 seconds for addressing and binding nanoparticles, 40 seconds for washing). The nanoparticle addressing/binding process can be monitored by changes in fluorescence intensity as each nanoparticle layer is deposited. The final multilayered 3-D structures are about two microns in thickness and 50 microns in diameter. Work is now focused on assembling "micron size" biosensor devices from bio-molecule derivatized luminescent and fluorescent nanoparticles. The proposed structure for a nanolayered glucose sensor device includes a base layer of biotin/streptavidin nanoparticles, a layer of glucose oxidase derivatized nanoparticles, a layer of peroxidase derivatized nanoparticles, a layer of quantum dots, and a final layer of biotin/streptavidin nanoparticles. Such a device will serve as a prototype for a wide variety of applications which includes other biosensor devices, lab-on a-chip devices, in-vivo drug delivery systems and "micron size" dispersible bio/chem sensors for environmental, military and homeland security applications.