One to Many Single Entity Electrochemistry Biosensing for Ultrasensitive Detection of microRNA.
Single entity electrochemistry (SEEC) a promising method for biosensing, has an intrinsic limitation on sensitivity since at most one colliding entity can be successfully triggered by one target. Here, we take advantage of one to many (1:n) signal amplification to develop a new single entity electrochemistry biosensing (SEECBS) integrating satellite magnetic nanoparticle (MN) DNA Pt nanoparticle (NP) conjugates, duplex specific nuclease (DSN) assisted Pt NPs releasing with stabilization and effective collision of small sized and nearly naked Pt NPs. Compared with conventional SEECBS, the 1:n SEECBS can successfully enrich ~2 nM Pt NPs by adding 50 aM microRNA (miRNA) in other words, ~4x107 Pt NPs can be triggered by one target. The proposed SEECBS allows the detection of 47 aM miRNA 21, nearly 6 orders of magnitude lower than the previous work, and discrimination of non target miRNAs containing even single nucleotide mismatch. Besides, this method has also been successfully demonstrated for quantification of miRNA in different cell lines. Therefore, the proposed method holds great potential for the application of SEECBS in early diagnosis and prognosis monitoring of cancer.
Analytical chemistry