Sensitive chemiluminescence aptasensor based on exonuclease-assisted recycling amplification

We report herein an exonuclease-assisted aptamer-based target recycling amplification strategy for sensitive and selective chemiluminescence (CL) determination of adenosine. This aptasensor is based on target-induced release of aptamers from capture probes immobilized on the 96-well plate surface, and thus leading to a decreased hybridization with gold nanoparticle-functionalized reporter sequences followed by a CL signal. The introduction of exonuclease III catalyzes the stepwise removal of mononucleotides from 3′-hydroxyl termini of duplex DNAs of aptamers, liberating the adenosine. Therefore, a single copy of target adenosine can lead to the release and digestion of numerous aptamer strands from the 96-well plates and ultimately an enhanced sensitivity is achieved. Experimental results revealed that the exonuclease-assisted recycling strategy enabled the monitoring of adenosine with wide working ranges and low detection limits (LOD: 0.5 nM). This new CL strategy might create a novel technology for the detection of various targets and could find wide applications in the environmental and biomedical fields.

A convenient signal amplification strategy for sensitive and selective chemiluminescence determination of adenosine is demonstrated which employs an endonuclease-based enzymatic recycling cleavage strategy in the aptasensing platform. This new strategy might create a novel technology for the detection of various targets and find wide applications in the environmental and biomedical fields.Figure optionsDownload as PowerPoint slideHighlights
► An Exo III-assisted aptamer-based target recycling amplification assay is reported.
► Exo III catalyzes the removal of nucleotides from aptamers, liberating the target.
► A decreased hybridization with gold probes is used as a readout signal.