Publications de Kannan Balasubramanian

Publications associées (29)

Electrochemical modification and photoelectronic properties of carbon nanotubes

This thesis reports on the investigations performed on electrochemical functionalization and photoelectronic transport properties of individual single-wall carbon nanotubes (SWCNTs). The first part of the thesis is concerned with the controlled modificatio ...

EPFL2005

Contact and edge effects in graphene devices

Klaus Kern, Marko Burghard, Kannan Balasubramanian

Electrical transport studies on graphene have been focused mainly on the linear dispersion region around the Fermi level(1,2) and, in particular, on the effects associated with the quasiparticles in graphene behaving as relativistic particles known as Dira ...

2008

Polymer-electrolyte gated graphene transistors for analog and digital phase detection

Klaus Kern, Marko Burghard, Kannan Balasubramanian

We present an alternating current (ac) circuit based on a misoriented bilayer graphene device for analog and digital phase detection. We exploit the ambipolar nature of the transfer characteristics of a misoriented bilayer graphene transistor. The transist ...

AIP American Institute of Physics2011

Enhancing the Electrochemical and Electronic Performance of CVD-Grown Graphene by Minimizing Trace Metal Impurities

Klaus Kern, Kannan Balasubramanian

The presence of unwanted impurities in graphene is known to have a significant impact on its physical and chemical properties. Similar to carbon nanotubes, any trace metals present in graphene will affect the electrocatalytic properties of the material. He ...

Wiley-V C H Verlag Gmbh2014

Surface enhanced Raman scattering of carbon nanotubes decorated by individual fluorescent gold particles

Klaus Kern, Marko Burghard, Kannan Balasubramanian, Tilman Assmus

Confocal optical microscopy was employed to study the effect of surface-enhanced Raman scattering on individual single-walled carbon nanotubes covered with isolated gold particles. The gold particles with diameters between 10 and 120 nm were deposited in l ...

2008

Template-free self-assembly of hierarchical ZnO structures from nanoscale building blocks

Klaus Kern, Kannan Balasubramanian

We study chemical bath deposition method for synthesizing large variety constructions of ZnO nanostructures. By varying reaction kinetics we control the shape, size and morphology to yield flower-like, rolling-pin-like, viscous-fingers-like and antenna-lik ...

Elsevier2010

Identifying Chemical Functionalization on Individual Carbon Nanotubes and Graphene by Local Vibrational Fingerprinting

Klaus Kern, Kannan Balasubramanian

Chemical functionalization of carbon nanotubes (CNTs) and graphene allows for fine-tuning their physical and chemical properties to realize fascinating new fundamental phenomena as well as exotic applications. A primary challenge in such endeavors is the n ...

Amer Chemical Soc2015

Spatially Resolved Potential Distribution in Carbon Nanotube Cross-Junction Devices

Klaus Kern, Marko Burghard, Kannan Balasubramanian

Crossed-nanotube junctions, the basic constituents of carbon nanotube networks, are investigated by scanning photocurrent microscopy. The location of the predominant electrostatic potential drop, at the electrical contacts or at the junction, is found to b ...

Wiley2009

Tunable Enhancement of Raman Scattering in Graphene-Nanoparticle Hybrids

Klaus Kern, Kannan Balasubramanian

The realization of graphene-gold-nanoparticle (G-AuNP) hybrids is presented here through a versatile electrochemical approach, which allows the continuous tuning of the size and density of the particles obtainable on the graphene surface. Raman scattering ...

Wiley-V C H Verlag Gmbh2014

Enzyme-Free Sugar Sensing in Microfluidic Channels with an Affinity-Based Single-Wall Carbon Nanotube Sensor

Klaus Kern, Kannan Balasubramanian

We present a novel nonenzymatic carbon nanotube sensor integrated in a microfluidic channel for the detection of sugars. The sensor is assembled as a liquid-gated field-effect transistor, with the transistor channel composed of 1 to 10 nanotubes, which are ...

2010

Real-Time Label-Free Direct Electronic Monitoring of Topoisomerase Enzyme Binding Kinetics on Graphene

Klaus Kern, Kannan Balasubramanian

Mono layer graphene field-effect sensors operating in liquid have been widely deployed for detecting a range of analyte species often under equilibrium conditions. Here we report on the real-time detection of the binding kinetics of the essential human enz ...

Amer Chemical Soc2015

Tuning the isoelectric point of graphene by electrochemical functionalization

Klaus Kern, Kannan Balasubramanian

The ability to control the charge-potential landscape at solid-liquid interfaces is pivotal to engineer novel devices for applications in sensing, catalysis and energy conversion. The isoelectric point (pI)/point of zero charge (pzc) of graphene plays a ke ...

Nature Publishing Group2015

Selective Enhancement of Carbon Nanotube Photoluminescence by Resonant Energy Transfer

Klaus Kern, Kannan Balasubramanian

We report on a simple method for enhancing the efficiency of photoluminescence (PL) emission from selected chiral forms of semiconducting single-wall carbon nanotubes (SWCNTs). The method is based on the use of a fluorescent dye (Nile blue A) that shows th ...

2009

Self-Assembled Electrical Biodetector Based on Reduced Graphene Oxide

Klaus Kern, Kannan Balasubramanian

Large-scale fabrication of graphene-based devices is an aspect of great importance for various applications including chemical and biological sensing. Toward this goal, we present here a novel chemical route for the site-specific realization of devices bas ...

2012

Marker-free on-the-fly fabrication of graphene devices based on fluorescence quenching

Klaus Kern, Kannan Balasubramanian

Graphene has been dominating the electronic research community recently, with a brisk surge in proposals for its use in novel devices. The aspirations of 2D-carbon-based electronics largely rely on the availability of a mass-production technique to obtain ...

2010

Effect of the electronic structure of carbon nanotubes on the selectivity of electrochemical functionalization

Klaus Kern, Marko Burghard, Kannan Balasubramanian

The functionalization of carbon nanotubes through electrochemical routes is gaining importance due to the high degree of control achievable and the ability to render the tubes with a variety of chemical and biological species. In this article, we report sy ...

2008

Carbon nanotube transistors - chemical functionalization and device characterization

Klaus Kern, Marko Burghard, Kannan Balasubramanian

This review presents an overview of the recent progress made in the field of carbon nanotube (CNT)-based field-effect transistors (FETs). Starting from the simplest device architectures, various methods reported for fabricating CNT-FETs are presented. The ...

Wiley2008

Field-effect-based chemical sensing using nanowire-nanoparticle hybrids: The ion-sensitive metal-semiconductor field-effect transistor

Klaus Kern, Kannan Balasubramanian

A new class of nanoscale devices called ion-sensitive metal-semiconductor field-effect transistors (nano-IS-MESFET) for sensing applications is reported. Nanoparticle-nanowire hybrids with active metal-semiconductor regions are operated as ion-sensitive fi ...

Amer Inst Physics2013

Electric field effect in graphite crystallites

Klaus Kern, Marko Burghard, Kannan Balasubramanian

Graphite is a highly anisotropic crystal with a quasi-two-dimensional electronic structure exhibiting high intrinsic charge carrier mobility. Here, we investigate the effect of an electric field on the resistance of individual graphite crystallites with a ...

AIP American Institute of Physics2012

25th Anniversary Article: Label-Free Electrical Biodetection Using Carbon Nanostructures

Klaus Kern, Kannan Balasubramanian

Nanostructures are promising candidates for use as active materials for the detection of chemical and biological species, mainly due to the high surface-to-volume ratio and the unique physical properties arising at the nanoscale. Among the various nanostru ...

Wiley-V C H Verlag Gmbh2014