Automated Combinatorial Process for Nanofabrication of Structures Using Bioderivatized Nanoparticles

Abstract

A fully automated electronic microarray control system (Nanochip 400 System) was used to carry out a combinatorial process to determine optimal conditions for fabricating higher order three-dimensional nanoparticle structures. Structures with up to 40 layers of bioderivatized nanoparticles were fabricated on a 400test site CMOS microarray using the automated Nanochip 400 System. Reconfigurable electric fields produced on the surface of the CMOS microarray device actively transport, concentrate, and promote binding of 40 nm biotin-and streptavidin-derivatized nanoparticles to selected test sites on the microarray surface. The overall fabrication process including nanoparticle reagent delivery to the microarray device, electronic control of the CMOS microarray and the optical/fluorescent detection, and monitoring of nanoparticle layering are entirely controlled by the Nanochip 400 System. The automated nanoparticle layering process takes about 2 minutes per layer, with 10e20 seconds required for the electronic addressing and binding of nanoparticles, and roughly 60 seconds for washing. The addressing and building process is monitored by changes in fluorescence intensity as each nanoparticle layer is deposited. The final multilayered 3D structures are about 2 mm in thickness and 55 mm in diameter. Multilayer nanoparticle structures and control sites on the microarray were verified by SEM analysis.

Electric-Field-Directed Self-Assembly of Active Enzyme-Nanoparticle Structures

“…Altogether the results showing enzyme-nanoparticle layer assembly and enzyme activity retention demonstrate an efficient and effective method of fabricating biological or chemical sensors. Site-specific layer assembly, demonstrated in this study as well as previous studies, means that multiple types of enzyme-nanoparticle structures can be fabricated on each chip in a combinatorial manner [ 37 ]. Additionally, various types of enzymes, proteins, or other biomolecules could be used in conjunction with a wide array of particle types as long as they have complementary binding mechanisms, such as the biotin-streptavidin scheme used here.…”

“…This powerful tool has enabled devices to be made which utilize the electric fields to enhance DNA hybridization, to form protein layers for biosensors, and to pattern cells [ 30 – 36 ]. Recently we have shown the ability to construct higher-order NP structures by electric-field-directed self-assembly through the specific interactions of complementary DNA sequences as well as through protein-molecule interactions (Figures 1(a) and 1(b) ) [ 14 , 37 , 38 ]. We now present the ability to integrate active enzymes into these NP structures by directed electrophoretic means ( Figure 1(c) ), thus providing a new bottom-up fabrication method for patterning and constructing structures from NPs in a rapid and combinatorial fashion atop a microarray.…”

Directed Hybridization of DNA Derivatized Nanoparticles into Higher Order Structures

“…Three dimensional structures with over forty alternating layers of biotin/streptavidin nanoparticles have been fabricated using this process. [58][59][60] Such results demonstrate a unique combination of using a microelectronic device produced by top-down technology (photolithography) to direct the bottom-up process of assembling bioderivatized nanocomponents into higher order structures.…”

“…While 20 layer structures were the maximum number of layers that could be fabricated reproducibly in this study, in earlier work 40 layer biotin/ streptavidin nanoparticle structures were produced. [58][59][60] It should be pointed out that in some cases up to 100 layer biotin/streptavidin nanoparticle structures could be fabricated (unpublished results, M. J. Heller); however, this high level of layering could not be carried out reproducibly. It was strongly suspected that the reproducibility problem was actually caused more by prior aggregation of the biotin and streptavidin nanoparticles than by the electric field fabrication process itself.…”

“…A concise overview of electric field techniques for on-chip manipulation and assembly of colloidal nanoparticles has also been recently compiled . More recently, we have demonstrated that these electric field techniques and devices can be used to carry out the highly parallel directed self-assembly of biotin and streptavidin derivatized nanoparticles into multilayered higher order structures. − The optimized electric field process allows nanoparticles at very low concentration in the bulk solution to be rapidly concentrated and specifically bound to the activated sites with minimal nonspecific binding. Three dimensional structures with over forty alternating layers of biotin/streptavidin nanoparticles have been fabricated using this process. − Such results demonstrate a unique combination of using a microelectronic device produced by top-down technology (photolithography) to direct the bottom-up process of assembling bioderivatized nanocomponents into higher order structures.…”