Sensitive ECL sensor for sequence-specific DNA from Mycobacterium tuberculosis based on N-(aminobutyl)-N-ethylisoluminol functionalized gold nanoparticles labeling

A novel sensor was developed for highly sensitive detection of the sequence-specific DNA of Mycobacterium tuberculosis (MTB) by using N-(aminobutyl)-N-(ethylisoluminol) (ABEI) functionalized gold nanoparticles (ABEI-AuNPs) as labels and using 81 bp segment derived from the MTB specific insertion sequence IS6110 as the target strand. Owing to the novel ECL labels and amplification of gold nanoparticles and biotin–streptavidin system, extremely high sensitivity for ss-DNA could be achieved with a low detection limit of 3.3 × 10−16 M and a wide linear dynamic range of 1.0 × 10−15–1.0 × 10−12 M. The DNA sensor also showed good precision, good stability, low detection limit for the detection of sequence-specific DNA from MTB in serum samples, which might be of application potential in clinical diagnosis.