Quantitative and selective DNA detection with portable personal glucose meter using loop-based DNA competitive hybridization strategy

Abstract

A portable, quantitative and selective DNA detection biosensor requiring only one step for target recognition and signal reporter generation using a loop-based DNA competitive hybridization assay and personal glucose meter (PGM) was developed. In the presence of target DNA, due to its competitive binding, the invertase-DNA conjugate was released which could be collected with the help of a magnet subsequently. The released invertase-DNA was used to catalyze the hydrolysis of sucrose into glucose with millions of turnovers which was target concentration dependent. We found that there was a linear relationship between the PGM signals and the target DNA concentration in the range of 100 pM to 100 nM with a detection limit of 100 pM. In addition, the sensor exhibits excellent sequence selectivity, being able to differentiate a single mismatch in the target DNA, and excellent anti-interference ability, having almost no effect in serum on the detection performance. The biosensor reported here is easier to operate, owning great potential in point of care testing in environments with limited resources and skilled personnel for rapid and sensitive detection of specific DNA sequence in real biological samples.