A surface plasmon resonance biosensor for the determination of the affinity of drugs for nucleic acids

In this paper we report the development of a DNA biosensor based on Surface Plasmon Resonance (SPR) for studying DNA-binding molecules. The study and the identification of compounds which can interact with DNA and interfere with gene expression is important in many areas such as pharmacological, medical or environmental analysis. The biosensor was generated by immobilising small oligonucleotides or calf thymus DNA on gold-coated SPR chips and studying the affinity of different drugs for the immobilised DNA. Affinity constants were calculated and compared with constants determined with other methods reported in literature. Other compounds were also investigated including environmental pollutants or substances used in molecular biology. The results obtained, compared well with data published in the literature and the system proved adequate for the evaluation of the behaviour of different compounds that interact directly with DNA. The system can be considered as a possible alternative to classical toxicity or genotoxicity tests.