Surface Functionalization of Hydrogen-Terminated Si for Biosensing Applications

• Published in: Journal of electronic materials Vol. 41; no. 5; pp. 830 - 836
• Main Authors: Bertani, Paul, Wen, Xuejin, Lu, Wu
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Boston Springer US 01.05.2012; Springer; Springer Nature B.V
• Subjects: Binding; Biosensors; Characterization and Evaluation of Materials; Charge; Chemistry and Materials Science; Condensed matter: structure, mechanical and thermal properties; Deoxyribonucleic acid; Drift; Electronics and Microelectronics; Exact sciences and technology; Fluorescence; General equipment and techniques; Homogeneity; Hybridization; Hydrogen; Instrumentation; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Ligands; Materials Science; Optical and Electronic Materials; Physics; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Silicon; Solid State Physics; Solid surfaces and solid-solid interfaces; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Surface functionalization; AFM; XPS; hybridization; fluorescence; DNA; Atomic force microscopy; Amines; Thiols; Fluorescence; Self-assembled layers; Hybridization; Thickness; Surface termination; Chemical modification; Adsorption; Functionalization; Ligands; Silicon; Biosensors; AFM, hybridization; Fluorescence microscopy; X-ray photoelectron spectra
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-012-1996-7

A process for functionalization of silicon for biosensing applications has been developed and has been verified by DNA attachment and hybridization. The functional monolayer is self-assembled on a hydrogen-terminated Si surface intended to be used on Si-based field-effect biosensors that are free of current drift and degradation. All defined stages of the functionalization process have been characterized by x-ray photoelectron spectroscopy. The N (1s) spectrum exhibits a narrow peak, suggesting good homogeneity of the amine group with a composition value of 1.88%. DNA hybridization evaluation has been done using fluorescence microscopy, confirming specific binding between ligand (probe DNA) and analyte (target DNA) with no physical adsorption observed. Atomic force microscopy data have been used to determine active area distances from the charge layer to the desired analyte, with average thickness of approximately 3 nm for the thiol-oligonucleotide layer.