新型磁性纳米电化学DNA生物传感器的研究

A Novel Electrochemical Biosensor for Deoxyribonucleic Acid Detection Based on Magnetite Nanoparticles

利用高分子磁性纳米粒子有效地将磁性分离、富集和化学修饰电极的电化学检测相结合,构建以亚甲基蓝为嵌入式杂交指示剂的电化学DNA生物传感器。此传感器对碱基错配的序列有较好的选择性。传感器对目标序列的响应在1×10-13～1×10-6mol/L范围内呈线性关系;检出限为4.3×10-14mol/L。这种新型的高分子磁性纳米粒子电化学DNA生物传感器具有高的灵敏度,其线性范围宽,成本低,为DNA的痕量分析提供了一种新的思路。

DNA detection is of great importance for clinical diagnosis and food safety. In this study, a sensitive electrochemical biosensor for DNA sequence mutation detection based on the magnetic nanoparticles separation and enrichment was proposed. For the proposed biosensor, the probe sequences were immobilized on the surface of carboxyl functioned magnetic nanoparticle to recognize the target sequences and methylene blue （MB）was used as hybridization indicator. In the range of 1×10^-13moL/L to 1× 10^-6mol/L, the concentra- tion of complementary sequence was linearly with the response of the electrochemical signal of MB and the detection limit was 4.3 ×10^-14 mol/L of target oligonucleotide. The improvement of detection sensitivity for this biosensor was mainly due to the magnetice enrichment and MCNT/GCE.