Portable glucose meter-based label-free strategy for target DNA detection

We herein developed a portable glucose meter (PGM)-based method for label-free target DNA detection, which relies on the cascade enzymatic reaction (CER) promoted by hexokinase and pyruvate kinase to link the amount of deoxynucleoside triphosphate (dNTP) with the glucose level. In the absence of target DNA or the presence of non-target DNA, the initial high concentration of dNTP, a phosphate source for hexokinase, is maintained because polymerase chain reaction (PCR) amplification is not executed, which results in the significant reduction of glucose level by the effective CER process. On the other hand, the PCR amplification works in the presence of target DNA by consuming dNTP and thus CER process cannot be effectively executed, leading to the maintenance of initial high glucose level. Finally, the resulting glucose level is simply measured by PGM without any tedious and labor-intensive steps. Utilizing the proposed strategy, we successfully analyzed the target genomic DNA derived from Hepatitis B virus (HBV) down to 102 copies with the high selectivity.