Functionalized gold nanoparticles for the ultrasensitive DNA detection

A major challenge in the area of DNA detection is the development of rapid methods that do not require the polymerase chain reaction (PCR) amplification of the genetic sample. The PCR amplification step increases the cost of the assay, the complexity of the detection and the quantity of DNA required for the assay. In this perspective, methods able to perform DNA analyses with ultrasensitivity have been recently investigated with the aim to develop new PCR-free detection protocols. Functionalized gold nanoparticles have played a central role in the development of such methods. Here possibilities offered by functionalized gold nanoparticle in the ultrasensitive detection of DNA are discussed. The different functionalization protocols available for gold nanoparticles and the principal DNA detection methods able to detect DNA at the femtomolar-attomolar level are presented.