Enhanced Sensing Performance of a Microchannel-Based Electrochemiluminescence Biosensor for Adenosine Triphosphate via a dsDNA Superstructure Amplification Strategy

The sensing performance of a microchannel-based electrochemiluminescence (ECL) biosensor is related to the change ratio of charge density on the surface of microchannels caused by a target recognition reaction. In this study, adenosine triphosphate (ATP) served as a model target. The dsDNA superstructures containing a capture probe (CP, containing an ATP aptamer sequence) and alternating units of ssDNA probes of P1 and P2, CP/(P1/P2)n, were grafted onto the inner wall of microchannels first. The CP in dsDNA superstructures captured ATP molecules, causing the release of dsDNA fragments containing alternating units of P1 and P2, (P1/P2)n. The target recognition reaction significantly changed the charge density of microchannels, which altered the ECL intensity of the (1,10-phenanthroline)ruthenium(II)/tripropylamine system in the reporting interface. The ECL intensity of the constructed system had a linear relationship with the logarithm of ATP concentration ranging from 1 fM to 100 pM with a detection limit of 0.32 fM (S/N = 3). The biosensor was successfully applied to detect ATP in rat brains.

Automated summary

In this study, a microchannel-based electrochemiluminescence (ECL) biosensor was used for the detection of adenosine triphosphate (ATP). The sensing performance of the biosensor relied on the change in charge density on the microchannel surface caused by a target recognition reaction. The system showed a linear relationship between ECL intensity and the logarithm of ATP concentration, with a detection limit of 0.32 fM.