William A. Ducker, Department of Chemistry, Virginia Tech Michael A. Calter, Department of Chemistry, University of Rochester NSF Proposal 9980770; Virginia Tech Proposal 99-1519-02
AFM -assisted, Nanometer-scale Modification of Semiconductor Chips
The goal of this Engineering Microsystems: "XYZ" on a Chip project is to develop a new technique for writing on a very small scale (nanolithography), and to apply nanolithography to the construction of a cell membrane on an electrode. Enzymes are mounted on the working tip of an Atomic Force Microscope (AFM) force sensor and the enzymes are used to perform a specific chemical reaction at a specific location dictated by the microscope. The initial objectives are to attach enzymes to the tips while maintaining chemical reactivity, and to synthesize a surface film that is easily modified by the enzyme. An AFM is also used to verify the accuracy of the writing process. To protect the delicate enzyme-tip, an AFM that has two separate probes is being developed. One probe is for writing and one is for reading in the same location. The enzyme-assisted nanolithographic technique will be used to fabricate a cell membrane on a semiconductor chip. The natural cell scaffold that supports the cell membrane will be attached to the chip by using the AFM enzyme tip to perform reactions at specific locations. The development of writing techniques with high spatial and chemical specificity enhances our ability to manufacture miniaturize electronic components and to perform parallel drug screening. The development of a realistic chip-mounted membrane is a key step in the preparation of biosensors.
