Prof. Dr. Kannan Balasubramanian
Profil
Forschungsthemen3
Bioelektrochemische Untersuchungen an funktionalisierten Graphen-Elektroden
Quelle ↗Förderer: Alexander von Humboldt-Stiftung Zeitraum: 05/2017 - 10/2018 Projektleitung: Prof. Dr. Kannan Balasubramanian
DFG-Sachbeihilfe: Graphen-beschichtete weiche elastische Materialien für die Untersuchung von Zelladhäsion: Lokale nanomechanische Eigenschaften und markierungsfreie elektronische Biosensorik
Quelle ↗Förderer: DFG Sachbeihilfe Zeitraum: 03/2021 - 02/2025 Projektleitung: Prof. Dr. Kannan Balasubramanian
DFG-Sachbeihilfe: Plasmonische Effekte in Metall-Nanostruktur-Graphen-Hybriden: Chemische Funktionalisierung und Einsatz in der Sensorik (IRIS Adlershof)
Quelle ↗Förderer: DFG Sachbeihilfe Zeitraum: 11/2019 - 08/2023 Projektleitung: Prof. Dr. Kannan Balasubramanian
Mögliche Industrie-Partner10
Stand: 26.4.2026, 19:48:44 (Top-K=20, Min-Cosine=0.4)
- 89 Treffer63.0%
- Interfaces in opto-electronic thin film multilayer devicesP63.0%
- Interfaces in opto-electronic thin film multilayer devices
- 57 Treffer61.0%
- Lösung gekoppelter Probleme in der Nanoelektronik (nanoCOPS)P61.0%
- Lösung gekoppelter Probleme in der Nanoelektronik (nanoCOPS)
- 61 Treffer61.0%
- Lösung gekoppelter Probleme in der Nanoelektronik (nanoCOPS)P61.0%
- Lösung gekoppelter Probleme in der Nanoelektronik (nanoCOPS)
- 57 Treffer61.0%
- Lösung gekoppelter Probleme in der Nanoelektronik (nanoCOPS)P61.0%
- Lösung gekoppelter Probleme in der Nanoelektronik (nanoCOPS)
- 34 Treffer58.8%
- Surface-enhanced Raman spectroscopy in liquid biopsy for breast cancerP58.8%
- Surface-enhanced Raman spectroscopy in liquid biopsy for breast cancer
- 36 Treffer58.8%
- Surface-enhanced Raman spectroscopy in liquid biopsy for breast cancerP58.8%
- Surface-enhanced Raman spectroscopy in liquid biopsy for breast cancer
- 11 Treffer57.3%
- DFG-Sachbeihilfe: Aufmerksamkeit und sensorische Integration im aktiven Sehen von bewegten ObjektenT57.3%
- SFB 1315/2: Mechanismen und Störungen der Gedächtniskonsolidierung: Von Synapsen zur SystemebeneP47.4%
- DFG-Sachbeihilfe: Aufmerksamkeit und sensorische Integration im aktiven Sehen von bewegten Objekten
- 13 Treffer57.2%
- EU: Context Sensitive Multisensory Object Recognition (HBP)P57.2%
- EU: Context Sensitive Multisensory Object Recognition (HBP)
- 13 Treffer57.2%
- EU: Context Sensitive Multisensory Object Recognition (HBP)P57.2%
- EU: Context Sensitive Multisensory Object Recognition (HBP)
- EU: Context Sensitive Multisensory Object Recognition (HBP)P57.2%
- EU: Context Sensitive Multisensory Object Recognition (HBP)
Publikationen25
Top 25 nach Zitationen — Quelle: OpenAlex (BAAI/bge-m3 embedded für Matching).
Small · 1754 Zitationen · DOI
Since their discovery, carbon nanotubes have attracted the attention of many a scientist around the world. This extraordinary interest stems from their outstanding structural, mechanical, and electronic properties. In fact, apart from being the best and most easily available one-dimensional (1D) model system, carbon nanotubes show strong application potential in electronics, scanning probe microscopy, chemical and biological sensing, reinforced composite materials, and in many more areas. While some of the proposed applications remain still a far-off dream, others are close to technical realization. Recent advances in the development of reliable methods for the chemical functionalization of the nanotubes provide an additional impetus towards extending the scope of their application spectrum. In particular, covalent modification schemes allow persistent alteration of the electronic properties of the tubes, as well as to chemically tailor their surface properties, whereby new functions can be implemented that cannot otherwise be acquired by pristine nanotubes.
Nature Nanotechnology · 732 Zitationen · DOI
Analytical and Bioanalytical Chemistry · 724 Zitationen · DOI
Advanced Materials · 289 Zitationen · DOI
Nanoparticles on an atomic carpet: Individual graphene sheets have been decorated with metal nanoparticles through electrochemistry. The attachment of Pd particles onto graphene renders it sensitive to hydrogen. The controlled functionalization of graphene paves the way for various electronic applications.
Applied Physics Letters · 120 Zitationen · DOI
Photoconductivity in individual semiconducting single-wall carbon nanotubes was investigated using a confocal scanning optical microscope. The magnitude of the photocurrent was found to increase linearly with the laser intensity, and to be maximum for parallel orientation between the light polarization and the tube axis. Larger currents were obtained upon illuminating the tubes at 514.5 nm in comparison to those at 647.1 nm, consistent with the semiconducting tubes having a resonant absorption energy at the former wavelength. Moreover, the determination of the photoresponse as a function of position along single nanotubes has proven to be a useful tool to monitor local electronic structure effects.
Nano Letters · 116 Zitationen · DOI
Commercial fabrication of field-effect transistors (FETs) using carbon nanotubes has been hindered as all current production procedures yield a mixture of metallic and semiconducting tubes. Herein, we present a generic approach utilizing electrochemistry for selective covalent modification of metallic nanotubes, resulting in exclusive electrical transport through the unmodified semiconducting tubes. Toward this goal, the semiconducting tubes are rendered nonconductive by application of an appropriate gate voltage prior to the electrochemical modification. The FETs fabricated in this manner display good hole mobilities and a ratio approaching 106 between the current in the ON and OFF state.
Nano Letters · 111 Zitationen · DOI
The realization of high-performance electrical devices incorporating single-wall carbon nanotubes critically depends on the minimization of charge transport barriers in the tubes and at the contacts. Herein we demonstrate photocurrent imaging as a fast and effective tool to locate such barriers within individual metallic nanotubes contacted by metal electrodes. The locally induced photocurrents directly reflect the existence of built-in electric fields associated with the presence of depletion layers at the contacts or structural defects along the tubes.
Journal of Materials Chemistry · 109 Zitationen · DOI
The application range of carbon nanotubes (CNTs) has been significantly expanded by the advent of reliable chemical functionalization methods. This article surveys electrochemistry-based approaches that have been devised for the covalent and non-covalent modification of CNTs, and highlights their increasing importance in the development of nanoscale and macroscopic CNT devices. The primary focus is on electrochemical protocols for selective functionalization of CNTs according to their electronic properties, as well as the fabrication of various types of CNT-based sensors for gases and (bio)molecules.
Analytical Chemistry · 94 Zitationen · DOI
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 controllably functionalized with boronic acid receptors. The devices show sensitivity to glucose in a concentration range of 5 to 30 mM. Furthermore, by controlling the type of nanotube-receptor coupling (as covalent or noncovalent) and by deploying a sensitive impedance-based detection technique, we corroborate in detail the transduction mechanism of our affinity-based sensor. In the case of covalent coupling, charge carrier scattering along the nanotubes is the dominant mechanism. While in the noncovalent case, surface charge effects dominate. The identification of the mechanism along with the tunability of the chemical coupling and the cost-effective integration in microchannels constitute a solid basis for the entry of nanotube-based sensors in lab-on-a-chip applications.
Biosensors and Bioelectronics · 93 Zitationen · DOI
Advanced Materials · 92 Zitationen · DOI
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 nanostructures, materials comprised of sp(2) -carbon enjoy a unique position due to the possibility to readily prepare them in various dimensions ranging from 0D, through 1D to 2D. This review focuses on the use of 1D (carbon nanotubes) and 2D (graphene) carbon nanostructures for the detection of biologically relevant molecules. A key advantage is the possibility to perform the sensing operation without the use of any labels or complex reaction schemes. Along this spirit, various strategies reported for the label-free electrical detection of biomolecules using carbon nanostructures are discussed. With their promise for ultimate sensitivity and the capability to attain high selectivity through controlled chemical functionalization, carbon-based nanobiosensors are expected to open avenues to novel diagnostic tools as well as to obtain new fundamental insight into biomolecular interactions down to the single molecule level.
Angewandte Chemie International Edition · 92 Zitationen · DOI
Finding that needle in the haystack: A label-free on-chip detection strategy based on carbon nanotubes (see picture) was used to detect an oligonucleotide target sequence of which less than 2000 copies were present in a 30 μL sample droplet, without the need for PCR. Instead, sensitive low-noise impedance measurement coupled to field-effect detection enabled attomolar DNA detection in a heterogeneous environment.
ACS Nano · 81 Zitationen · DOI
We present a simple approach to improving the quality of CVD grown graphene, exploiting a Cu(111) foil catalyst. The catalyst is epitaxially grown by evaporation on a single crystal sapphire substrate, thickened by electroplating, and peeled off. The exposed surface is atomically flat, easily reduced, and exclusively of (111) orientation. Graphene grown on this catalyst under atmospheric CVD conditions and without wet chemical prereduction produces single crystal domain sizes of several hundred micrometers in samples that are many centimeters in size. The graphene produced in this way can easily be transferred to other substrates using well-established techniques. We report mobilities extracted using field-effect (as high as 29 000 cm(2) V(-1) s(-1)) and Hall bar measurement (up to 10 100 cm(2) V(-1) s(-1)).
Advanced Materials · 77 Zitationen · DOI
Electrochemical coating of individual single‐walled carbon nanotubes (SWCNTs) with thin films obtained via oxidative coupling of an amine or reductive coupling of an aromatic diazonium salt is reported. The same SWCNTs have been characterized before and after modification by electrical transport measurements and confocal Raman spectroscopy (see Figure, electrode structure white, background dark blue, and SWCNTs light blue to red).
physica status solidi (a) · 72 Zitationen · DOI
Abstract 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 main focus is laid on the use of chemical functionalization strategies both at a tube and at a device level to improve the performance of the devices. In addition to solid dielectric gate insulators, the use of liquids or solid polymer electrolytes as effective electrochemical gating media is outlined. Following this, device parameters of the various CNT‐FETs are compared and discussed. Finally, the utility of scanning photocurrent microscopy as an efficient characterization tool to estimate electronic band‐profiles of CNT‐FETs is highlighted. The review concludes with future perspectives in this rapidly emerging field. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inverse Problems · 71 Zitationen · DOI
Convenient tools for nondestructive evaluation of solids can be electromagnetic and/or elastodynamic waves; since their governing equations, including acoustics, exhibit strong structural similarities, the same inversion concepts apply. In particular, the heuristic SAFT algorithm (synthetic aperture focusing technique) can be - and has been - utilized for all kinds of waves, once a scalar approximation can be justified. Relating SAFT to inverse scattering in terms of diffraction tomography, it turns out that linearization is the most stringent inherent approximation. Hence, the results of nonlinear inversion schemes such as contrast source inversion are compared to the output of SAFT for a carefully designed ultrasonic experiment. In addition, it will be shown via synthetic as well as experimental data that SAFT can be extended to electromagnetic vector fields and to an inhomogeneous and/or anisotropic background material.
Scientific Reports · 70 Zitationen · DOI
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 key role in a number of physico-chemical phenomena occurring at the graphene-liquid interface. Supported by theory, we present here a methodology to identify the pI/pzc of (functionalized) graphene, which also allows for estimating the nature and extent of ion adsorption. The pI of bare graphene (as-prepared, chemical vapor deposition (CVD)-grown) is found to be less than 3.3, which we can continuously modify up to 7.5 by non-covalent electrochemical attachment of aromatic amino groups, preserving the favorable electronic properties of graphene throughout. Modelling all the observed results with detailed theory, we also show that specific adsorption of ions and the substrate play only an ancillary role in our capability to tune the pI of graphene.
ChemElectroChem · 67 Zitationen · DOI
Abstract Graphene is expected to revolutionize several application areas ranging from portable energy conversion and storage to miniaturized biosensors for medical applications. In this endeavor, the control of surface characteristics is an essential aspect for understanding fundamental phenomena occurring at the graphene‐liquid interface. In this comprehensive review, we address recent progress in the investigation of the interfacial characteristics of monolayer graphene and methods for modulating the physical and chemical properties of this interface. We focus on the electrochemistry and field‐effect measurements in liquid, which provide an improved understanding of the unique graphene‐liquid interface, with due consideration of the influence of the underlying substrate and structural defects in graphene. Finally, we present reported examples of using single graphene monolayers in miniaturized devices for realizing sensors, neural interfaces and batteries.
International Journal of Electrochemical Science · 66 Zitationen · DOI
Cyclic voltammetric behavior of electrolytic grade copper powder immobilized on paraffin impregnated graphite electrode is studied in 0.1 M KOH solution. Few micrograms of copper powder is mechanically immobilized on the surface of paraffin impregnated graphite electrode and subjected to electrochemical characterization. Well separated, stable and sharp redox peaks for both Cu (I) and Cu (II) oxides are observed. Lowering the upper positive potential limit by increments of 5 mV is found to be directly proportional to the changes in the reduction peaks of both oxides which in turn is decided by the hydrous oxide film. In the absence of hydrous oxide film, the solid state redox transformations were stoichiometrically controlled and quasi reversible. This study helps to understand the 95-99 % efficiency of copper recovery process in our pilot plant.
ChemPhysChem · 65 Zitationen · DOI
A pH sensor based upon gentle covalent modification of individual metallic single-wall carbon nanotubes is demonstrated. The sensing mechanism relies upon the protonation-dependent charge carrier scattering (see figure) by N,N-diethylaniline moieties anchored to the tube sidewall. This novel approach holds promise to extend the accessible range of nanotube-based (bio)chemical sensors.
The Journal of Physical Chemistry C · 61 Zitationen · DOI
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 low densities on the tubes' sidewalls by an electrochemical method. In the spectra, Raman peaks associated with the nanotubes were found to be superimposed on a broad luminescence background originating from the metal particles. With increasing particle size, both the luminescence intensity as well as the Raman enhancement increased at longer wavelengths. This finding is consistent with a size-dependent broadening of the gold plasmon frequency and a corresponding extension of the energetic range for local field enhancement on the particle surface. In addition, wavelength-dependent experiments revealed a maximum Raman intensity when both nanotube and metal particle were in optical resonance.
ChemPhysChem · 57 Zitationen · DOI
We report here on the interaction of the fluorescent dye rhodamine B (RB) with single-walled carbon nanotubes (SWCNTs). We observe that SWCNTs statically quench the fluorescence of RB by forming a stable ground state complex. Careful spectroscopic analysis indicates that the complex formation is efficient mainly with certain chiral forms. We propose three different applications utilizing this quenching mechanism and the associated complexation. Firstly, the quenching efficiency can be utilized as a measure for the characterization and quantification of nanotube dispersions. Secondly, we demonstrate that the specific complexation of RB can be deployed to enrich certain chiral forms in suspension. Finally, we show that RB can be effectively used to visualize nanotubes deposited on substrates.
Applied Physics Letters · 57 Zitationen · DOI
Nanosized gap structures have been fabricated via electromigration-induced breaking of gold-palladium nanowires. The application of low breaking voltages resulted in gap junctions exhibiting single-electron tunneling signatures at low temperature (2K), which are attributed to the formation of metallic nanoclusters during the electromigration process. Strikingly, the I–V characteristics of most samples displayed a close similarity to those typically attributed to electrical transport through single molecules contacted by incorporation into electromigration gaps. The finding that the breaking of bare nanowires alone is sufficient to create rich differential conductance features should be taken into account in future electrical studies on molecular-scale structures.
Small · 52 Zitationen · DOI
Abstract A scalable bottom‐up solution‐based approach for the site‐specific realization of ZnO nanowire (ZnO‐NW)‐based field‐effect transistors for sensing applications in liquids is reported. The nanowires are grown across predefined electrodes patterned by photolithography. Site specificity is attained by the use of nanoparticles acting as seeds. Using integrated on‐chip microchannels and microfabricated gate electrodes, electrochemically gated ZnO‐NW network transistors functioning in liquids are demonstrated. The optimized devices are rendered sensitive to pH through chemical functionalization. The unique combination of the sensitivity, site specificity, scalability, and cost effectiveness of the technique opens up avenues for the routine realization of one‐dimensional nanostructure‐based chemical and biosensors for analytical and diagnostic applications.
ACS Nano · 51 Zitationen · DOI
Monolayer 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 enzyme, topoisomerase I interacting with substrate molecules (DNA probes) that are immobilized electrochemically on to monolayer graphene strips. By monitoring the field-effect characteristics of the graphene biosensor in real-time during the enzyme-substrate interactions, we are able to decipher the surface binding constant for the cleavage reaction step of topoisomerase I activity in a label-free manner. Moreover, an appropriate design of the capture probes allows us to distinctly follow the cleavage step of topoisomerase I functioning in real-time down to picomolar concentrations. The presented results are promising for future rapid screening of drugs that are being evaluated for regulating enzyme activity.
Kooperationen1
Bestätigte Forscher↔Partner-Paare aus HU-FIS — Gold-Standard-Positive für das Matching.
Nationale Universität San Martin
DFG-Sachbeihilfe: Graphen-beschichtete weiche elastische Materialien für die Untersuchung von Zelladhäsion: Lokale nanomechanische Eigenschaften und markierungsfreie elektronische Biosensorik
university
Stammdaten
Identität, Organisation und Kontakt aus HU-FIS.
- Name
- Prof. Dr. Kannan Balasubramanian
- Titel
- Prof. Dr.
- Fakultät
- Mathematisch-Naturwissenschaftliche Fakultät
- Institut
- Institut für Chemie
- Arbeitsgruppe
- Analytische Chemie / Nanoanalytik
- Telefon
- +49 30 2093-66470
- HU-FIS-Profil
- Quelle ↗
- Zuletzt gescrapt
- 26.4.2026, 01:02:16