Label-free DNA detection with PNA modified long period fiber grating-based sensor

In the present work a LPFG has been inscribed in a boron germania co-doped optical single mode fiber. Subsequently, the external surface of the optical fiber has been modified with peptide nucleic acid (PNA) probes, in our previous work the functionalization and hybridization of the surface of a microstructured optical fiber has been demonstrated. After that, DNA molecules in a 120nM solution, which are matched with the PNA probes, have been captured using the fiber modified surface. Experimental results have demonstrated the feasibility of label-free detection of DNA molecules using a LPFG in an optical fiber. The shift of the grating resonant wavelength has been measured.