Nanopore detection of copper ions using a polyhistidine probe

• Published in: Biosensors & bioelectronics Vol. 53; pp. 453 - 458
• Main Authors: Wang, Guihua, Wang, Liang, Han, Yujing, Zhou, Shuo, Guan, Xiyun
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier 15.03.2014
• Subjects: Biological and medical sciences; Biosensing Techniques - methods; Biosensors; Biotechnology; chelates; chelating agents; cobalt; copper; Copper - chemistry; Copper - isolation & purification; detection limit; Fundamental and applied biological sciences. Psychology; Hemolysin Proteins - chemistry; hemolysins; Histidine - chemistry; Ions - chemistry; Ions - isolation & purification; metal ions; Metals - chemistry; Methods. Procedures. Technologies; Molecular Probes; Nanopores; nickel; Various methods and equipments; zinc; Biosensor; Nanopore sensing; Chelation; Nanostructure; Nanopore; Copper; Detection; Probe; Histidine polymer; Polyhistidine
• ISSN: 0956-5663; 1873-4235; 1873-4235
• DOI: 10.1016/j.bios.2013.10.013

We report a stochastic nanopore sensing method for the detection of Cu(2+) ions. By employing a polyhistidine molecule as a chelating agent, and based on the different signatures of the events produced by the translocation of the chelating agent through an α-hemolysin pore in the absence and presence of target analytes, trace amounts of copper ions could be detected with a detection limit of 40 nM. Importantly, although Co(2+), Ni(2+), and Zn(2+) also interacts with the polyhistidine molecule, since the event residence times and/or blockage amplitudes for these metal chelates are significantly different from those of copper chelates, these metal ions do not interfere with Cu(2+) detection. This chelating reaction approach should find useful application in the development of nanopore sensors for other metal ions.