Many cancer cells (lung cancer, brain cancer and breast cancer) have a special proteins in surface of cell’s membrane (epidermal growth factor receptor, EFGR), which does not contain these proteins in healthy cells, The detection of these proteins is crucial to determine whether contains cancer cells in human body, it is a breakthrough in the treatment of cancer, is a new target for the treatment of cancer. Gold nanorods in wavelength and long axis excitation light irradiation absorption peak position close, can quickly put the energy into heat energy and release into the environment, because it has the characteristics of gold nanorods can be used as drug delivery or biological molecules and controlled release carrier. After the gold nanorods are modified by surface, they are used as target drugs. Through the specific recognition and binding ability of gold nanorods and cancer cells modified to binding ability strong hundreds of times than healthy cells, this drug carrying most of the adsorption of gold nanorods in cancer cells, and then use a specific wavelength of laser irradiation, the drug delivery of gold nanorods directly released in cancer cells to kill cancer cells, the effect will be to minimize the side effects of drugs.
LSPR absorption peaks of Gold nanorods on the dielectric property of the surrounding media is very sensitive, when the gold nanorod surface molecular bonding reaction, LSPR absorption peak occurred for red shift, gold nanorods itself provides the internal reference, eliminate the error for gold ball don’t have itself reference, improve the detection sensitivity. A specific functional group or antibody modified gold nanorods can be used to detect proteins, DNA or some harmful substances.The detection limit is up to nmol/L, especially for the early diagnosis of cancer.
Effect of the gold nanorods under near-infrared excitation on cellular damage is small, suitable for observation in vivo, photobleaching’s effect is small, and the near infrared light than visible light transmittance is high in tissue, up to several centimeters, it not was disturbed by its own background fluorescence and light scattering in tissue, hence can be used for biological imaging in deep tissue. In the gold nanorod surface modified antibody, the antibody modified gold nanorods labeled to cancer cells through the specific interaction between antigen and antibody, gold nanorods by laser irradiation on cancer cells by three-dimensional tissue two-photon luminescence imaging, imaging depth can reach 75um.Using specific laser light irradiation, the gold nanorods labeled cancer cells two photon emission intensity than the cancer cell autofluorescence was strong 3 orders of magnitude, fully demonstrated the superiority of the gold nanorods as the near infrared fluorescent probe.