title: Simultaneous Ionic Current and Potential Detection of Nanoparticles by a Multifunctional Nanopipette.
abstract: Nanopore sensing-based technologies have made significant progress for single molecule and single nanoparticle detection and analysis. In recent years, multimode sensing by multifunctional nanopores shows the potential to greatly improve the sensitivity and selectivity of traditional resistive-pulse sensing methods. In this paper, we showed that two label-free electric sensing modes could work cooperatively to detect the motion of 40 nm diameter spherical gold nanoparticles (GNPs) in solution by a multifunctional nanopipette. The multifunctional nanopipettes containing both nanopore and nanoelectrode (pyrolytic carbon) at the tip were fabricated quickly and cheaply. We demonstrated that the ionic current and local electrical potential changes could be detected simultaneously during the translocation of individual GNPs. We also showed that the nanopore/CNE tip geometry enabled the CNE not only to detect the translocation of single GNP but also to collectively detect several GNPs outside the nanopore entrance. The dynamic accumulation of GNPs near the nanopore entrance resulted in no detectable current changes, but was detected by the potential changes at the CNE. We revealed the motions of GNPs both outside and inside the nanopore, individually and collectively, with the combination of ionic current and potential measurements.
authors.affiliation: Physics Department and ∥Biomolecular Science Institute, Florida International University , Miami, Florida 33199, United States.|College of Resources and Environmental Engineering and §College of Materials and Metallurgy, Wuhan University of Science and Technology , Wuhan, Hubei 430081, China.
authors.forename: Namuna
authors.initials: N
authors.lastname: Panday
authors.affiliation: Physics Department and ∥Biomolecular Science Institute, Florida International University , Miami, Florida 33199, United States.|College of Resources and Environmental Engineering and §College of Materials and Metallurgy, Wuhan University of Science and Technology , Wuhan, Hubei 430081, China.
authors.forename: Gongming
authors.initials: G
authors.lastname: Qian
authors.affiliation: Physics Department and ∥Biomolecular Science Institute, Florida International University , Miami, Florida 33199, United States.|College of Resources and Environmental Engineering and §College of Materials and Metallurgy, Wuhan University of Science and Technology , Wuhan, Hubei 430081, China.
authors.forename: Xuewen
authors.initials: X
authors.lastname: Wang
authors.affiliation: Physics Department and ∥Biomolecular Science Institute, Florida International University , Miami, Florida 33199, United States.|College of Resources and Environmental Engineering and §College of Materials and Metallurgy, Wuhan University of Science and Technology , Wuhan, Hubei 430081, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Chang
authors.affiliation: Physics Department and ∥Biomolecular Science Institute, Florida International University , Miami, Florida 33199, United States.|College of Resources and Environmental Engineering and §College of Materials and Metallurgy, Wuhan University of Science and Technology , Wuhan, Hubei 430081, China.
authors.forename: Popular
authors.initials: P
authors.lastname: Pandey
authors.affiliation: Physics Department and ∥Biomolecular Science Institute, Florida International University , Miami, Florida 33199, United States.|College of Resources and Environmental Engineering and §College of Materials and Metallurgy, Wuhan University of Science and Technology , Wuhan, Hubei 430081, China.
authors.forename: Jin
authors.identifier: 0000-0002-2633-9809
authors.initials: J
authors.lastname: He
keywords: multimode sensing; nanoelectrode; nanoparticle accumulation; nanopipette; nanopore; potential sensing