Gene detection device including gold nanoparticles and gene detection method using gold nanoparticles

A gene detection method comprising:

• (a) attaching a controlled number of probe DNAs for target gene detection to the surface of gold nanoparticles to form probe-gold nanoparticles, wherein each of the probe DNAs comprise a target capture DNA and a sensing DNA;
• (b) mixing the probe-gold nanoparticles in a sample such that the target capture DNA is hybridized with a single strand target gene, wherein the target capture DNA complementarily bound to the target gene comprises an exposed 3′ end;
• (c) degrading the exposed 3′ ends of the target capture DNAs complementarily bound to the target gene by a nuclease to remove from the probe DNA the target capture DNA complementarily bound to the target gene, thereby forming a product of the probe DNA comprising the sensing DNA;
• (d) allowing the target gene to return to its single strand;
• (e) repeating (b) to (d) to amplify the number of the product;
• (f) synthesizing complementary blocking DNAs along probe DNAs of unreacted gold nanoparticles using a DNA polymerase, DNA strands as primers complementarily binding to target capture DNAs of the probe DNAs of the unreacted gold nanoparticles, and dNTPs, whereby the probe DNAs of the unreacted gold nanoparticles become double-stranded;
• and
• (g) allowing the sensing DNA of the product to complementarily bind to a probe linker DNA immobilized on a surface of a sensor to generate detection signals, wherein the detection signals are indicative of the target gene.