Ding Caifeng, Zhong Hua, Zhang Shusheng
Key Laboratory of Eco-Chemical Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China.
Biosens Bioelectron. 2008 Mar 14;23(8):1314-8. doi: 10.1016/j.bios.2007.12.005. Epub 2008 Jan 22.
A novel and sensitive biosensor for the determination of short sequence of DNA based on flow injection (FI)-chemiluminescence (CL) system of luminol-H2O2-Cu2+ was developed in the present work. The DNA probe labeled with copper sulfide nanoparticles (CuS NPs) could hybridize with target DNA immobilized on glass-carbon electrode (GCE). The hybridization events were monitored by the CL intensity of luminol-H2O2-Cu2+ after the cupric ions was dissolved from the hybrids. A preconcentration process of cupric ions was performed by anodic stripping voltammetry (ASV) technology to improve the sensitivity of the biosensor. Under the optimum conditions, the CL intensity was proportional to the concentration of target DNA in the range of 2.0 x 10(-12)-1.0 x 10(-10)M. A detection limit of 5.5 x 10(-13)M of target DNA was achieved. The CL intensity of two-base mismatched sequences and noncomplementary sequences were also detected. The experiments indicated that two-base mismatched sequences showed weaker CL intensity and noncomplementary sequences gave no response at all.
在本研究中，基于鲁米诺-H₂O₂-Cu²⁺的流动注射（FI）-化学发光（CL）体系，开发了一种用于测定短DNA序列的新型灵敏生物传感器。用硫化铜纳米颗粒（CuS NPs）标记的DNA探针可与固定在玻碳电极（GCE）上的目标DNA杂交。从杂交体中溶解出铜离子后，通过鲁米诺-H₂O₂-Cu²⁺的化学发光强度监测杂交事件。采用阳极溶出伏安法（ASV）技术对铜离子进行预富集，以提高生物传感器的灵敏度。在最佳条件下，化学发光强度与目标DNA浓度在2.0×10⁻¹² - 1.0×10⁻¹⁰ M范围内呈正比。目标DNA的检测限达到5.5×10⁻¹³ M。还检测了两碱基错配序列和非互补序列的化学发光强度。实验表明，两碱基错配序列的化学发光强度较弱，而非互补序列则完全无响应。
