Ultrasensitive detection of HIV DNA using an electrochemical biosensor with branched DNA amplification

• Published in: International journal of electrochemical science 2023-10, Vol.18 (10), p.100286, Article 100286
• Main Authors: Ma, Mingyi, He, Li, Shi, Xiaoxue, Wang, Yanchao, Hai, Hong, Wei, Xiaoping
• Format: Article
• Language: English
• Subjects: ATRP; Branched-chain loading; Electrochemical biosensor; HIV DNA; Probe clusters
• ISSN: 1452-3981; 1452-3981
• DOI: 10.1016/j.ijoes.2023.100286

This paper presents a novel strategy for ultrasensitive detection of human immunodeficiency virus (HIV) DNA by an electrochemical biosensor. By the shearing cycle of the target DNA (T-DNA), a large amount of complimentary sequence probes (CS probe DNA) are obtained. Then, the Zr4+ functional probe DNA containing many branched DNAs is captured. Next, the initiator α-bromophenylacetic acid is connected to the branched chains of probe DNA by esterification reaction. Numerous electroactive monomers, namely, ferrocenylmethyl methacrylate (FMMA), are produced at the end of the branched chains by electrochemically mediated atomic transfer radical polymerization reaction. The signal of FMMA is greatly enhanced due to a large number of branched chain-loaded probe clusters containing numerous FMMA. T-DNA can be detected with a linear range of 0.1 fM–10 nM with a detection limit of 0.037 fM. The sensor is highly sensitive and selective. It has been applied to the detection of HIV DNA in human serum samples, and it has potential application prospects in the early clinical diagnosis of AIDS. •A strategy for ultrasensitive detection of HIV DNA was proposed at amol/L concentration.•A large amount of CS probe DNA were obtained by Exonuclease III shearing the cyclic target DNA.•Multiple DNA branched chains connected to CS probe DNA were used to load probe clusters.•Probe cluster containing numerous probes FMMA were formed on DNA branch chain by eATRP reaction.