title: Node-pore sensing: a robust, high-dynamic range method for detecting biological species.
abstract: Resistive-pulse sensing (RPS), which is based on measuring the current pulse produced when a single particle transits a pore or channel, is an extremely versatile technique used to determine the size and concentration of cells and viruses and to detect single molecules. A major challenge to RPS is dynamic range: smaller particles in a heterogeneous sample can go undetected because of low signal-to-noise ratios (SNRs) and the fact that the pore size must be commensurate with that of the largest particles. Here, we describe a fundamentally different pore that provides an unprecedented dynamic detection range, from tens of nanometers to several microns in size, without the need for pre-sorting or filtration. Because of its unique geometry--nodes inserted along the channel--our pore produces distinct electronic signatures that overcome low SNRs. We demonstrate the power of our device by directly detecting and enumerating human immunodeficiency virus (HIV) in human plasma.
authors: Department of Mechanical Engineering, University of California at Berkeley, Berkeley, CA 94720-1740, USA.
authors: Karthik R
authors: KR
authors: Balakrishnan
authors: George
authors: G
authors: Anwar
authors: Matthew R
authors: MR
authors: Chapman
authors: Trongtuong
authors: T
authors: Nguyen
authors: Anand
authors: A
authors: Kesavaraju
authors: Lydia L
authors: LL
authors: Sohn
mesh_terms: D004129:Dimethylpolysiloxanes / Q000737:chemistry; D017097:Electric Impedance; D004563:Electrochemistry / Q000295:instrumentation*; D005583:Fourier Analysis; D006678:HIV / Q000302:isolation & purification; D006801:Humans; D055616:Microtechnology; D016062:Porosity; D013997:Time Factors
chemical_list: D004129:Dimethylpolysiloxanes; C013830:baysilon