Application And Study Of DNA Biosensor Based On Cation-Exchange Of Cus Nanoparticles

Cation-exchange (CX) reactions could occur completely and reversibly in ionic nanocrystals at room temperature with unusually fast reaction rates because of their large surface areas and small volumes. The cation-release process happens instantaneously and involves no enzymatic or catalytic reagents except the cations added to initiate ion exchange. The main idea of the reseach was to combine the CX reactions of CuS nanoparticles and AgNO3 with DNA biosensor to detect DNA, MicroRNAs, mutant DNA and DNA methytransferase.DNA technology plays an important role in the field of analytical chemistry due to various forms of signal amplification. Till now the application of the cation exchange efficient reaction is restricted to fluorescent detection. The study attempts to apply this cation exchange reaction to chemiluminescence detection and visual detection of gold nanoparticles.1.The study combined cation exchange technology and chemiluminescence to detect DNA and MicroRNAs. Under the best experimental conditions the detection result revealed a good linear relationship with the target DNA concentration ranging from 5.0 × 10-14 M to 1.0 × 10-11 M and target MicroRNAs concentration ranging from 6.0 × 10 -16 M to 5.0 × 10-11 M. The research verified the specificity of this method by detecting MicroRNAs with different sequences; the practicality of this method has been verified by testing the target with 293T cell samples.2. The research cation exchange technology and colorimetric detection to detect mutant DNA and DNA methytransferase by using gold nanoparticles. Under the best experimental conditions, the detection result revealed a good linear relationship with the target mutant DNA concentration ranging from 1.0 × 10-10 M to 1.0 ×10-8 M, through UV detection. The color changes can also be observed with the naked eye. The target DNA methytransferase ranging from 5 U·mL-1 to 120 U·mL-1 have a good linear relationship with the detection result, and can also be observed with the naked eye. This method was simple, sensitive and time save. This method can be used to detect target mutant DNA and DNA methytransferase with the naked eye in a low detection limit.