Abstract: By using aptamer as the capture probe and gold nanoparticles-invertase-complementary DNA conjugates as the detection probe, a competitive dopamine hydrochloride (DH) aptasensor was constructed based on a glucose meter. In the absence of DH, the detection probe was captured on a 96-well plate by the aptamer through complementary base pairing. When it was present, DH interacted with its aptamer with a strong affinity forcing the detection probe away from the 96-well plate to catalyze the transformation of sucrose into glucose. Accordingly, indirect detection of dopamine hydrochloride concentration was performed by measuring glucose concentration with a glucose meter. When the incubation time and the enzymatic reaction time were 30 min and 120 min, respectively, the glucose meter signal intensity increase linearly with the increase of DH concentration in the range of 0.45–10 mmol/L with a correlation coefficient of up to 0.997, and the relative standard deviations (RSDs) were 0.9%, 1.4% and 4.8% at 8.0, 3.0 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 application of glucose meter to the detection of other non-glucose, but also has potential application in the fields of health care and food safety detection.

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