title: Detecting DNA targets through the formation of DNA/CTAB complex and its interactions with liquid crystals.
abstract: In this paper, we report the formation of a DNA/cetyl trimethylammonium bromide (CTAB) complex on a solid surface and its interaction with a thin layer of liquid crystals (LC) supported on the surface. Our results show that when the surface is decorated with DNA only, the LC gives a bright image, but when the surface is decorated with the DNA/CTAB complex, the LC becomes dark when the surface density of CTAB is above 5.25 ± 0.13 × 10(13)/cm(2). To exploit this phenomenon for detecting DNA targets, we used a surface decorated with electroneutral PNA probes for capturing DNA targets, and then treated the surface with 0.1 mM of CTAB. In the presence of DNA targets, a PNA/DNA/CTAB complex is formed and that leads to a dark image on the thin layer of the LC supported on the surface. Moreover, DNA targets with a complementary, 1-base mismatch and non-complementary sequence can be differentiated by using this method. This study provides a new principle for the label-free detection of DNA targets without any fluorescent labels.
authors: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117576.
authors: Siok Lian
authors: SL
authors: Lai
authors: Kun-Lin
authors: KL
authors: Yang
mesh_terms: D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry*; D004247:DNA / Q000032:analysis* / Q000737:chemistry; D050866:Liquid Crystals / Q000737:chemistry*; D046228:Microarray Analysis; D009693:Nucleic Acid Hybridization; D020135:Peptide Nucleic Acids / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013499:Surface Properties
chemical_list: D002593:Cetrimonium Compounds; D020135:Peptide Nucleic Acids; D004247:DNA; D000077286:Cetrimonium