Figure 3.

This example is a modification of a microarray for the detection of human papilloma virus. In this example, biotin-labeled PCR products are hybridized with immobilized oligonucleotides. The chip is incubated in an anti-biotin antibody-conjugated gold nanoparticle solution. The silver enhancement by the gold nanoparticles bound to the biotin precipitates silver metal particles at the chip surfaces. This blocks light irradiated from above, which can be measured, allowing detection and quantitative analysis of the target DNA.