초록 |
Plasmonic properties of noble metallic nanostructures depend on the size, shape, position, orientation, etc, and can be altered by interaction between probe and target species on the metal surfaces. We achieved highly facile preparation of nanometals by biomolecule-directed synthesis. Subsequently, we fabricated nanoplasmonic biosensors with these nanoparticles by assembling dark-field microscope and scattering spectrophotometry, where each individual nanoparticle serves as an independent probe for miniature optical sensors based on localized surface plasmon resonance. The structure-defined nanoparticles offer ultrahigh sensitivity with detection limits of several molecules. Practically, we developed ultrasensitive biosensors for detecting biomarkers of cancer diagnosis, such as p53 proteins, DNA mutation and DNA methylation. The results were verified by highly consistent in vitro transcription efficiencies and closely met the theoretical and clinical expectations. |