NIRT: Enhancing the Sensitivity and Stability of Biosensors by Novel Nanostructures

University Of Georgia Research Foundation Inc, Athens GA

Investigators

Abstract

In this project, we propose to develop nanoscale 3D structures and use the nanostructures as 3D substrates to address problems in biosensing. To achieve this objective, we will expand our newly developed nanofabrication technique - glancing angle deposition (GLAD) - to fabricating nanoscale 3D pillars such that the size, height, spacing, shape and location of the nanopillars (or nanorods) will be controlled, and multiple layers of nanorods will be realized. This development will provide several unique features to suit the needs for biosensing applications. We will derive nanoscale glucose sensors by functionalizing the nanorods through enzyme immobilization. With this proposed project, we aim to achieve the following specific objectives: (1) to fabricate nanostructures with controlled parameters, such as size, spacing, height, shape and location, for developing nanoelectrodes; (2) to immobilize enzymes onto well-prepared nanostructures to achieve high sensitivity and activity; (3) to control the size and separation of the top layer nanorods to be within 20 nm, so that a mechanical filtration can be realized for antifouling; (4) to passivate the top layer nanorods using self-assembly monolayer (SAM) technique to further improve antifouling; and (5) to fabricate prototype glucose sensors and assess their sensitivity, stability and antifouling behavior. (1) The intellectual merit of the proposed activity: The novelty of this project lies in the following areas: (1) with the multilayer and vertically aligned and high aspect-ratio metallic nanorods serving as 3D electrodes, the sensitivity and response time of the glucose sensors will be significantly improved; (2) with the size and spacing of the top-layer nanorods controlled less than 20 nm, a mechanical filtration to prevent protein penetration will be achieved; (3) with selective passivation (using a specific SAM, such as Oligo(ethylene glycol)-terminated alkanethiols) of the top-layer nanorods, further protein adsorption will be prevented; and (4) the entire development process is compatible with mass microfabrication procedures. Thus, we anticipate that by integrating the novel nanostructures into biosensing applications, we will be able to address concerns of sensitivity, biofouling (via both the chemical passivation and mechanical filtration), and miniaturization. The proposed project is feasible because it is well within the expertise of all PIs. (2) The broader impacts resulting from the proposed activity: This proposed project seeks to integrate biotechnology and nanotechnology for advancing fundamental knowledge in this nascent frontier, and for deriving useful applications to benefit the general public and humankind. The success of this project will not only lead to a new technique for developing high performance glucose sensors, but also serve as a knowledge base, groundwork, and technical foundation for developing nanoscale structures for other types of chemical and biological sensors. It will also open new opportunities for incorporating multilayer nanostructures (as nano-membranes) into realization of multifunctional and multi-specie chemical and biological sensing. This project will also provide unique opportunities for both graduate and undergraduate students to gain precious hands-on experience and training in the multidisciplinary fields of materials science, nanotechnology, and biological engineering.