基于纳米金胶标记DNA探针的电化学DNA传感器研究

以纳米金胶为标记物,将其标记于人工合成的5-端巯基修饰的寡聚核苷酸片段上,制成了具有电化学活性的金胶标记DNA电化学探针;在一定条件下,使其与固定在玻碳电极表面的靶序列进行杂交反应,利用ssDNA与其互补链杂交的高度序列选择性和极强的分子识别能力,以及纳米金胶的电化学活性,实现对特定序列DNA片段的电化学检测以及对DNA碱基突变的识别.

Studies on an Electrochemical DNA Biosensor Based on Gold Nanoparticle-labeled DNA Probe

An electrochemical detection method for the analyzing sequence-specific DNA using gold nanoparticle labeled oligonucleotide DNA probes has been developed. Target DNA were covalently immobilized on a glass carbon electrode and incubated with gold nanoparticle-labeled DNA probes, containing a complementary sequence. Binding events were monitored by electrochemical signal of gold nanoparticle hybridized to the electrode surface. The signal difference permits to distinguish the match of two perfectly complementary DNA strands from the near-perfect match where just one base pair was wrong. The sensitivity of this electrochemical DNA biosensor has been detected and a detection limit of 1.0 nmol/L of oligonucleotides was achieved.