Surface second harmonic generation of oligonucleotides on surfaces

摘要

Laser induced surface second harmonic generation (SSHG) has been applied to study the nature of oligonucletides on glass surfaces. A very strong SSH signal from most of the investigated oligonucletides was observed. The oligonucleotides were found to be resistant to damage from the incident laser radiation, up to peak pulse powers 8MW. The surface second harmonic signal intensity has been shown to be strongly dependent on the angle of the incident laser beam with respect to the sample surface. The study of both angle and polarization dependencies of glass surfaces coated with 12 mer oligonucletide AAAAAATTTTTT and fluorescein fTTTTTTTTTTTT labelled 12 mer oligonucletide is reported. The SSHG technique has been used for quantitative measurements to determine the surface concentration of several oligonucletide samples. The measured surface concentration dependence offers the potential for the development of oligonucleotide assays based on surface second harmonic generation.