Trying to incorporate quantum dots into biological systems has proven difficult due to their lack of biocompatibility and the toxicity of heavy metals inside cells. Recently developed carbon nanodots retain the advantages of quantum dots, but can function in biological media. Xianogang Qu and researchers at the Chinese Academy of Sciences incorporated carbon nanodots in a thrombin detection assay using DNA aptamers. Thrombin contains two binding sites that are recognized by different aptamers on both a silica nanoparticle and carbon nanodot. The multi-binding site capabilities of aptamers allow for greater sensitivity when compared to single site antibodies, and the fluorescent signal of the carbon nanodot is only detected when bound to thrombin on the silica nanoparticle. Click on the paper below to read more, it will be free to read until November 16th.
Aptamer carbon nanodot sandwich used for fluorescent detection of protein
Bailu Xu, Chuanqi Zhao, Weili Wei, Jinsong Ren, Daisuke Miyoshi, Naoki Sugimoto and Xiaogang Qu
Analyst, 2012, 137, 5483-5486