Fig. 6
From: Colorimetric bacteria sensing of Pseudomonas aeruginosa using gold nanoparticle probes
A brief description of the purpose of identifying the DNA by gold nanoparticles probe. A When two oligonucleotide probes labeled with gold are attached to the target, it causes the accumulation of gold nanoparticles. B When the target DNA is not present and the solution remains red, the spectrophotometer analysis shows the maximum absorption at 524 nm. In the presence of the target DNA, gold nanoparticles accumulate. The hybridization between the probe and the target DNA leads to a change of color from red to violet and reduces absorption at the wavelength of 558 nm