Preparation of Porous Silicon Substrate for Protein Microarray Fabrication by Double-Cell Electrochemical Etching Method

Abstract

Uniformly porous silicon substrate with large surface area(12 mm. 58 mm) was prepared by simple double. cell electrochemical etching method. After functionalizing with epoxide groups, the porous silicon substrate can be employed to fabricate the protein microarray. Well-known biomolecular recognition system (the interaction of mouse IgG with rabbit anti-mouse IgG antibody) was chosen to establish this new microarray format by proof of principle experiment. We found that the detection sensitivity of the mouse IgG microarray was dependent on the preparing conditions of porous silicon substrate including etching current density, etching time, and concentration of HF solution. Under the optimal conditions such as 500 mA/cm(2) of etching current density, 450 s of etching time and 25% HF solution, specific binding could be detected using rabbit anti. mouse IgG antibody at concentrations as low as 10 mu g/L with a dynamic range of 0.32-10.0 mg/L. The experimental results demonstrate that the as-prepared porous silicon substrate could be used to fabricate the protein microarrays with high reaction capability.