DNA-gold conjugates for the detection of specific molecular interactions.

DNA chips are an emerging technology for parallel detection of DNA molecules, with applications ranging from medicine to environmental monitoring. The typical set-up includes fluorescence labeling for detection of binding events on the chip surface. Here another labeling technique based on gold nanoparticles is presented. These labels are much more stable, and their optical signal is less influenced by the environment. The specificity of gold-labeled DNA probes and the ease of detection using optical reflection or transmission is demonstrated. In conclusion, gold-labeling is a promising candidate for more robust and reliable DNA-chip detection.