Abstract: By using aptamer as capture probe and gold nanoparticles-invertase-complementary DNA conjugates as detection probe, a competitive dopamine hydrochloride(DH) aptasensor was constructed based on the detection of glucose meter. In the absence of DH, the detection probe was captured on 96-well plate by the aptamer through complementary base pairing. When it was in presence, DH interacted with its aptamer with a stronger affinity forcing the detection probe away from the 96-well plate to catalytic sucrose into glucose, then indirect detection of dopamine hydrochloride concentration was performed by measuring glucose concentration with a glucose meter. When dopamine hydrochloride incubation time and enzymatic reaction time were 30min and 120min respectively, the glucose meter signal intensity increase linearly with the increase of DH concentration in the range of 0.45~10 mmol/L with the correlation coefficient up to 0.997, and the relative standard deviations (RSD) were 0.9%, 1.4% and 4.8% at 8.0 mmol/L, 3.0 mmol/L and 0.8 mmol/L (n=5), respectively. The prepared sensor has the advantages of simple operation, good stability and high selectivity, which not only broadens the detection of other non-glucose targets using glucose meter, but also has potential application in the detection fields of health care and food safety.

Key words: aptamer, aptasensor, glucose meter, gold nanoparticles, dopamine hydrochloride, food safety