Cell membranes cloaked magnetic nanoparticles for target recycling detection of nucleic acid

Accurate analysis of human immunodeficiency virus (HIV) related molecules are significant for early diagnosis and therapy of acquired immune deficiency syndrome (AIDS). In this work, a novel electrochemical biosensor for HIV DNA detection is developed. Target induced recycling amplification is designed to enhance the sensitivity. Magnetic nanoparticles are used for facile separation, which are first cloaked by red blood cell membranes and then modified with DNA strands. Target initiated formation of multiple DNA three-way junctions occurs at the interface and the nanoconjugates can be conveniently immobilized on the surface of magnetic electrode. The measured responses from electrochemical species carried on the nanoconjugates can be used to reflect the level of target DNA. This proposed electrochemical method shows excellent sensing performances with a linear range from 0.1 fM to 1 pM. The limit of detection is as low as 35 aM. It is also successfully applied in clinical serum samples with satisfactory results. Therefore, this approach has great potential use for point-of-care testing of HIV DNA and provides a general strategy for various virus analysis.