Nanoparticle-Based Optical Detection of Molecular Interactions for DNA-Chip Technology

We adapted the nanoparticle-labeling technique from microscopical applications for DNA-chip detection. Nanoparticles can be detected by simple optical means (e.g., reflection or transmission), and exhibit a high stability. So alternative optical readout devices can be applied for the detection of specific DNA-binding on microstructured spots of complementary, surface-immobilized capture DNA. Several devices were tested, and the binding of gold-labeled DNA to complementary and non-complementary sequences was investigated using optical detection of the gold-labeled substrates before and after silver enhancement.