Preparation and application of mercury ion sensor based on photonic crystal enhanced fluorescence

The invention provides preparation and application of a mercury ion sensor based on photonic crystal enhanced fluorescence. The mercury ion sensor is composed of photonic crystal, a nucleic acid fluorescence molecular probe and a DNA assistant probe. The photonic crystal is used as a substrate, and strong affinity between thymidine (T) of DNA and Hg is employed to allow fluorescence group ROX labeled aptamer and a complementary sequence to compose a fluorescence detection system. A photonic crystal film is formed on a glass sheet substrate by prepared PS microspheres through vertical deposition self-assembly. Gold is sprayed on the surface of the photonic crystal; and based on Au-S bonding effect, mercapto group modified fluorescence group ROX labeled aptamer undergoes self-assembly on the surface of the photonic crystal, wherein the emission wavelength of ROX accords with the forbidden band of the photonic crystal, so fluorescence enhancing effect is achieved. According to the invention, fluorescence signal intensity of a nucleic acid fluorescence molecule is improved by using the principles of enhancement of fluorescence through the photonic crystal, so sensitivity and accuracy of sensor detection are improved.