The Hong Kong University of Science and Technology, Kowloon, Hong Kong.
Biosens Bioelectron. 2009 Dec 15;25(4):803-8. doi: 10.1016/j.bios.2009.08.034. Epub 2009 Aug 28.
A novel electrochemical method for multiplex detection of sequence-specific DNA and single nucleotide polymorphism (SNP) that requires no probe immobilization is reported. The immobilization-free detection of target DNA is realized by the use of a neutrally charged peptide nucleic acid (PNA) probe labeled with an electroactive indicator and a negatively charged ITO electrode. Upon hybridization between the target DNA and the complementary PNA probe, electrostatic repulsion between the negative backbone of the DNA/PNA duplex and the negative surface of the ITO electrode prevents the electroactive indicator from approaching the electrode, resulting in a significantly suppressed electrochemical signal. Multiplex DNA or SNP detection is enabled by using multiple PNA probes with different sequences labeled with different distinguishable electroactive indicators. Due to the immobilization-free nature of this detection scheme, no interference is found between the simultaneous detection of multiple target DNAs or SNPs. This simple and robust immobilization-free multiplex DNA and SNP detection strategy may find applications in a wide range of fields especially in point-of-care testing.
报道了一种无需探针固定的新型电化学方法，用于多重检测序列特异性 DNA 和单核苷酸多态性 (SNP)。通过使用带有电化学生物指示剂的中性肽核酸 (PNA) 探针和带负电荷的 ITO 电极，实现了对靶 DNA 的无固定化检测。在靶 DNA 与互补 PNA 探针杂交后，DNA/PNA 双链的负骨架与 ITO 电极的负表面之间的静电排斥作用阻止了电化学生物指示剂接近电极，从而导致电化学信号显著抑制。通过使用带有不同可区分电化学生物指示剂的不同序列的多个 PNA 探针，实现了多重 DNA 或 SNP 的检测。由于这种检测方案无需固定化，因此在同时检测多个靶 DNA 或 SNP 时不会产生干扰。这种简单而强大的无固定化多重 DNA 和 SNP 检测策略可能会在广泛的领域得到应用，特别是在即时检测中。
