A carbon nanotubes based fluorescent aptasensor for highly sensitive detection of adenosine deaminase activity and inhibitor screening in natural extracts

• Carbon nanotube as a functional matrix for developing novel fluorescent aptasensor.
• Rapid, high sensitive, and high selective analysis of adenosine deaminase activity in homogeneous solution.
• The screening of adenosine deaminase inhibitor from 10 natural extracts traditional Chinese medicines through the proposed system.
• The fluorescent aptasensor for adenosine deaminase has a detection limit of as low as 0.002 U/mL.

A carbon nanotubes (CNTs) based fluorescent aptasensor was developed for adenosine deaminase (ADA) activity detection and inhibitor screening by using adenosine (AD) as the substrate. This sensing system consists of CNTs, AD, split anti-AD aptamer fragment and dye-labeled aptamer fragment. In the absence of ADA, two aptamer fragments bind simultaneously with AD to form an AD-aptamer complex. This AD-aptamer complex cannot adsorb onto CNTs, and has high fluorescence intensity. When ADA is introduced into this system, ADA can convert AD into inosine, which has not affinity to the split anti-AD aptamer fragment. Thus, the split anti-AD aptamer fragments were adsorbed onto CNTs via strong π–π stacking interactions, resulting in the quenching of the fluorescence of the dye-labeled aptamer fragment. The proposed aptasensor can detect ADA activity from 0.005 to 0.2 U/mL with a low detection limit of 0.002 U/mL. Moreover, it has been also demonstrated that this CNTs-based fluorescence aptasensor is suitable for ADA inhibitor screening from traditional Chinese medicine (TCM). Considering the superior sensitivity and specificity, the proposed CNTs-based fluorescent aptasensor can be expected to provide a simple, cost-effective and sensitive platform for the detection of ADA activity and screening of potential drugs.

We developed a new carbon nanotube-based fluorescent aptasensor that allows rapid, sensitive, and selective detection of adenosine deaminase activity and inhibitor screening in homogenous solution.Figure optionsDownload as PowerPoint slide