摘要

In this paper a highly sensitive and selective aptamer biosensor for quantitative detection of a model target, dopamine, was developed by using a ubiquitous personal glucose meter (PGM). Dopamine aptamer was combined on the gold nanoparticles (AuNPs) modified 96-well plate. The signal probe, dopamine aptamer complementary strand (DNA2)-invertase-AuNP5, which was prepared with DNA2, invertase and AuNPs was immobilized onto the 96-well plate through the hybridization of aptamer and DNA2. Upon the addition of dopamine, aptamer would interact with it, and the hybridization of aptamer and DNA2 was destroyed and the DNA2-invertase-AuNP5 probe was forced away from the surface of the 96well plate. The invertase carried on AuNPs catalyzed the hydrolysis of sucrose to produce a large amount of glucose for quantitative readout by the PGM. PGM signal versus the concentration of dopamine was linear in the range from 0.08 to 100 mu mol L-1. The detection limit was 0.03 mu mol L-1 in 2 mu L, (similar to 60 femtomol), and the relative standard deviation (RSD) was 3.7% at 5 mu mol L-1 (n = 7). The developed method is successfully demonstrated for dopamine determination in human blood serum. Due to its simplicity, sensitivity and selectivity, this biosensor offers a promising approach for the detection of dopamine and other biomolecules.