Kinetics of DNA Functionalized Gold Nanoparticle Aggregation Toward Colorimetric Sensing
Abstract
Gold nanoparticles have unique optoelectronic properties such as a large extinction coefficient that are advantageous for optical sensing applications. When they interact with light, gold nanoparticles have a characteristic red color in solution, but when they aggregate, their color changes to blue. When DNA strands are attached to their surface they can act as colorimetric sensors to detect target small molecules, metal ions, nucleic acids, and proteins by using the color changes of the gold nanoparticles. Some of the advantages of using DNA-functionalized gold nanoparticles as sensors are high sensitivity, specificity, low cost, easy fabrication, and visual detection by the human eye. These nanoparticles offer a favorable platform for high-technology applications such as bioanalysis, development of therapeutic agents, and drug delivery. Therefore, the importance of researching these nanoparticles lies in the combination of both the optical properties of the gold nanoparticles and the molecular recognition functions of the DNA.
Gold nanoparticles of an average diameter of 15 nm were synthesized using the citrate reduction method. Gold nanoparticles were functionalized with two different thiol-modified DNA strands and were aggregated in the presence of linker DNA. The nucleotides in the linker DNA were base-paired to the DNA attached to the Gold nanoparticles. The changes in their absorption spectra were measured at different times. This research talks about the kinetics of the aggregation reaction.
Kinetics of DNA Functionalized Gold Nanoparticle Aggregation Toward Colorimetric Sensing
Gold nanoparticles have unique optoelectronic properties such as a large extinction coefficient that are advantageous for optical sensing applications. When they interact with light, gold nanoparticles have a characteristic red color in solution, but when they aggregate, their color changes to blue. When DNA strands are attached to their surface they can act as colorimetric sensors to detect target small molecules, metal ions, nucleic acids, and proteins by using the color changes of the gold nanoparticles. Some of the advantages of using DNA-functionalized gold nanoparticles as sensors are high sensitivity, specificity, low cost, easy fabrication, and visual detection by the human eye. These nanoparticles offer a favorable platform for high-technology applications such as bioanalysis, development of therapeutic agents, and drug delivery. Therefore, the importance of researching these nanoparticles lies in the combination of both the optical properties of the gold nanoparticles and the molecular recognition functions of the DNA.
Gold nanoparticles of an average diameter of 15 nm were synthesized using the citrate reduction method. Gold nanoparticles were functionalized with two different thiol-modified DNA strands and were aggregated in the presence of linker DNA. The nucleotides in the linker DNA were base-paired to the DNA attached to the Gold nanoparticles. The changes in their absorption spectra were measured at different times. This research talks about the kinetics of the aggregation reaction.