Kelvin Probe Force Microscopy Analysis of the Covalent Functionalization and DNA Modification of Gallium Phosphide Nanorods

David N. Richards, Purdue University
Dmitry Y. Zemlyanov, Birck Nanotechnology Center, Purdue University
Albena Ivanisevic, North Carolina State University

Abstract

The growth, covalent functionalization, and subsequent DNA modification of gallium phosphide (GaP) nanorods is presented. Analysis of the nanorods by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) revealed important information regarding their physical properties such as the presence of twinning defects. The nanorods were deposited onto glass substrates for further fiinctionalization and biomolecule immobilization. Plasma cleaning was employed to remove the surfactant present on the nanorods' surfaces. Kelvin probe force microscopy (KPFM) was used to analyze the extent of plasma cleaning and how it affected the fiinctionalization that employed thiol chemistry. KFPM analysis of the subsequent modification of functionalized nanorods with single-stranded DNA (ssDNA) revealed that immobilization was dependent on the amount of plasma cleaning to which the nanorods had been exposed. Nanorods were then exposed to the cDNA strand and KPFM was again used to detect successful hybridization.

Discipline(s)

Nanoscience and Nanotechnology