基于纳米金/蔗糖酶构建核酸适体传感器检测盐酸多巴胺

采用核酸适体做捕获探针，纳米金-蔗糖酶-互补DNA偶合物做检测探针，构建竞争型核酸适体传感器，并结合血糖仪实现对盐酸多巴胺的检测。未加靶目标时，检测探针与核酸适体通过碱基互补配对结合；加入靶目标后，核酸适体与靶目标强亲和力竞争结合，使检测探针脱离捕获探针并催化蔗糖转化为葡萄糖，通过血糖仪检测葡萄糖浓度间接检测盐酸多巴胺浓度。结果表明，在靶目标孵育时间和蔗糖酶催化时间分别为30?min和120?min时，盐酸多巴胺的线性检测范围为0.45～10?mmol/L，相关系数为0.997。对8.0、3.0、0.8?mmol/L盐酸多巴胺标准液进行多次测量，相对标准偏差分别为0.9%、1.4%、4.8%。所制备传感器具有操作简单、稳定性好、选择性高的特点，不仅拓宽了血糖仪对其他非糖标志物的检测，而且在医疗卫生和食品安全检测领域具有应用潜力。

Gold Nanoparticles and Invertase-Based Aptasensor for Detection of Dopamine Hydrochloride

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.