Integrated DNA detection system on silicon substrate with photodiodes

Abstract

This paper describes the process in developing of a fully integrated approach for Deoxyribo-Nucleic-Acid (DNA) diagnosis and gene mapping with photodiodes. The objectives and methodologies of DNA analysis based on traditional microarrays are briefly reviewed. The issues of material compatibility between DNA materials and silicon-based materials are evaluated. Reasons for the selection of covalent attachment of synthetic DNA to self-assembled monolayer films on silicon dioxide as immobilization method are addressed. Atomic force microscopy (AFM) and microscope images are used to verify the efficiency of DNA probe immobilization and the subsequent DNA hybridization. With the consideration of process compatibility between silicon processing and biochemical material handling, necessary process modification in photodiode fabrication is described. Measured signal from photodiodes with the hybridized DNA samples containing fluorescent labeled from the DNA probe microarrays on silicon substrates can be clearly distinguished from those without fluorescent labeled. The result demonstrated that the technique could be used for DNA identification purpose