Label-free direct electronic detection of biomolecules with amorphous silicon nanostructures

摘要

We present the fabrication and characterization of a nano-scale sensor made of amorphous silicon for the label-free,electronic detection of three classes of biologically important molecules:ions,oligonucleotides,and proteins.The sensor structure has an active element which is a 50 nm wide amorphous silicon semicircle and has a total footprint of less than 4 mu m~2.We demonstrate the functionalization of the sensor with receptor molecules and the electronic detection of three targets:ions,short single-stranded DNAs,and streptavidin.The sensor is able to reliably distinguish single base-pair mismatches in 12 base long strands of DNA and monitor the introduction and identification of straptavidin in real-time.The versatile sensor structure can be readily functionalized with a wide range of receptor molecules and is suitable for integration with high-speed electronic circuits as a post-process on an integrated circuit chip.