title: Open carbon nanopipettes as resistive-pulse sensors, rectification sensors, and electrochemical nanoprobes.
abstract: Nanometer-sized glass and quartz pipettes have been widely used as a core of chemical sensors, patch clamps, and scanning probe microscope tips. Many of those applications require the control of the surface charge and chemical state of the inner pipette wall. Both objectives can be attained by coating the inner wall of a quartz pipette with a nanometer-thick layer of carbon. In this letter, we demonstrate the possibility of using open carbon nanopipettes (CNP) produced by chemical vapor deposition as resistive-pulse sensors, rectification sensors, and electrochemical nanoprobes. By applying a potential to the carbon layer, one can change the surface charge and electrical double-layer at the pipette wall, which, in turn, affect the ion current rectification and adsorption/desorption processes essential for resistive-pulse sensors. CNPs can also be used as versatile electrochemical probes such as asymmetric bipolar nanoelectrodes and dual electrodes based on simultaneous recording of the ion current through the pipette and the current produced by oxidation/reduction of molecules at the carbon nanoring.
authors.affiliation: Key Laboratory of Cluster Science (Ministry of Education of China) and Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry, Beijing Institute of Technology , Beijing 100081, P. R. China.
authors.forename: Keke
authors.initials: K
authors.lastname: Hu
authors.forename: Yixian
authors.initials: Y
authors.lastname: Wang
authors.forename: Huijing
authors.initials: H
authors.lastname: Cai
authors.forename: Michael V
authors.initials: MV
authors.lastname: Mirkin
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
authors.forename: Gary
authors.initials: G
authors.lastname: Friedman
authors.forename: Yury
authors.initials: Y
authors.lastname: Gogotsi