Label-free Detection of DNA Hybridization in Homogeneous Solution with Cation Conjugated Polymers by using a Light Scattering Technique

摘要

When oligonucleotide probes hybridize with the complementary DNA target in homogeneous solution, the duplex DNA formed can be combined with water-soluble cation conjugated polymers (CCP)-Poly(9,9-bis(6-N,N,N-trimethylammonium)hexyl)fluorenylene phenylene (PFP) through strong electrostatic interactions and produce greatly enhanced light scatting in the presence of cetyltrimethylammonium bromide (CTAB). By using a light scattering technique with a common spetrofluorimeter, the target DNA can be sensitively determined in the concentration range of 0.5～10 nM. Moreover, it was found that the enhanced light scattering has well selectivity against one base mismatch at the DNA duplex terminal, which may open a new way for the sensitive detection of single nucleotide polymorphism (SNP) in a label-free and cost-effective manner.