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.

Graphical abstractA 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 full-size imageDownload 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.