Andreas Dahlin

Andreas Dahlin
Chalmers University of Technology · Department of Chemistry and Chemical Engineering

Professor

About

73
Publications
24,845
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
3,779
Citations
Introduction
I work with functional nanostructures: In my group we fabricate new structures and functionalize them chemically in order to evaluate them for various applications. Our work is strongly interdisciplinary and we aim to develop new bioanalytical devices or synthetic biological systems on the nanoscale. We are also addressing fundamental scientific questions, for instance within supramolecular chemistry and polymer physics. Please see my webpage adahlin.com for further information!
Additional affiliations
November 2016 - September 2020
Chalmers University of Technology
Position
  • Professor (Associate)
March 2012 - October 2016
Chalmers University of Technology
Position
  • Professor (Assistant)
August 2011 - February 2012
Chalmers University of Technology
Position
  • PostDoc Position
Education
August 1999 - June 2004
Chalmers University of Technology
Field of study
  • Bioengineering

Publications

Publications (73)
Article
Plasmonic metasurfaces for color generation are emerging as important components for next generation display devices. Fabricating bright plasmonic colors economically and via easily scalable methods, however, remains difficult. Here, the authors demonstrate an efficient and scalable strategy based on colloidal lithography to fabricate silver‐based...
Article
Full-text available
Surface plasmon resonance is a very well-established surface sensitive technique for label-free analysis of biomolecular interactions, generating thousands of publications each year. An inconvenient effect that complicates interpretation of SPR results is the "bulk response" from molecules in solution, which generate signals without really binding...
Article
Full-text available
Interfaces functionalized with polymers are known for providing excellent resistance towards biomolecular adsorption and for their ability to bind high amounts of protein while preserving their structure. However, making an interface that switches between these two states has proven challenging and concepts to date rely on changes in the physiochem...
Article
Full-text available
Surface plasmon resonance (SPR) is a highly useful technique in biology and is gradually becoming useful also for materials science. However, measurements to date have been performed almost exclusively on gold, which limits the possibility to probe chemical modifications of other metals. In this work we show that 20 nm Pd and Pt films work "fairly...
Article
Full-text available
Dynamic control of structural colors across the visible spectrum with high brightness has proven to be a difficult challenge. Here, this is addressed with a tuneable reflective nano‐optical cavity that uses an electroactive conducting polymer (poly(thieno[3,4‐b]thiophene)) as spacer layer. Electrochemical doping and dedoping of the polymer spacer l...
Article
Full-text available
Reflective displays or “electronic paper” technologies provide a solution to the high energy consumption of emissive displays by simply utilizing ambient light. However, it has proven challenging to develop electronic paper with competitive image quality and video speed capabilities. Here, the first technology that provides video speed switching of...
Article
Here, the research field of nanoplasmonic sensors is placed under scrutiny, with focus on affinity-based detection using refractive index changes. This review describes how nanostructured plasmonic sensors can deliver unique advantages compared to the established surface plasmon resonance technique, where a planar metal surface is used. At the same...
Article
Full-text available
Background Transrectal prostate biopsy (TRbx) transfers colonic bacteria into prostatic tissue, potentially causing infectious complications, including sepsis. Our objective was to determine whether biopsy needle shape, surface properties and sampling mechanism affect the number of bacteria transferred through the colon wall, and evaluate a novel n...
Article
Full-text available
The possibility of actively controlling structural colors has recently attracted a lot of attention, in particular for new types of reflective displays (electronic paper). However, it has proven challenging to achieve good image quality in such devices, mainly because many subpixels are necessary and the semitransparent counter electrodes lower the...
Article
Full-text available
Polymer brushes are widely used to alter the properties of interfaces. In particular, poly(ethylene glycol) (PEG) and similar polymers can make surfaces inert toward biomolecular adsorption. Neutral hydrophilic brushes are normally considered to have static properties at a given temperature. As an example, PEG is not responsive to pH or ionic stren...
Article
Full-text available
Nuclear Pore Complexes (NPCs) regulate bidirectional transport between the nucleus and the cytoplasm. Intrinsically disordered FG-Nups line the NPC lumen and form a selective barrier, where transport of most proteins is inhibited whereas specific transporter proteins freely pass. The mechanism underlying selective transport through the NPC is still...
Article
Full-text available
The synthesis and thermoresponsive properties of surface-attached poly(N-isopropylacrylamide)-co-N,N′-methylene bisacrylamide (PNIPAM-co-MBAM) networks are investigated. The networks are formed via SI-ARGET-ATRP (“grafting-from”) on thiol-based initiator-functionalized gold films. This method is reliable, well controlled, fast, and applicable to pa...
Article
Full-text available
We report for the first time that the protonation behavior of weak polyelectrolyte brushes depends very strongly on ionic strength. The pKa changes by one pH step per order of magnitude in salt concentration. For low salt concentrations (~1 mM), very high pH is required to deprotonate a polyacidic brush and very low pH is required to protonate a po...
Article
Full-text available
Plasmonic structural colors have recently received a lot of attention. For many applications there is a need to actively tune the colors after preparing the nanostructures, preferably with as strong changes in the optical response as possible. However, to date there is a lack of systematic investigations on how to enhance contrast in electrically i...
Article
Full-text available
Techniques for immobilization and release of proteins are of general interest but challenging to develop. Here we show a new method for high-capacity (several µg/cm2) immobilization of proteins in polyelectrolyte...
Article
Full-text available
Solid state nanopores are central structures for many applications. To date, much effort has been spent on controlled fabrication of single nanopores, while relatively little work has focused on large...
Article
Catalysis by enzymes on surfaces has many applications. However, strategies for efficient enzyme immobilization with preserved activity are still in need of further development. In this work we investigate polyelectrolyte brushes prepared by both grafting-to and grafting-from with the aim to achieve high catalytic activity. For comparison, self-ass...
Article
Full-text available
Biosensors based on plasmonic nanostructures are widely used in various applications and benefit from numerous operational advantages. One type of application where nanostructured sensors provide unique value in comparison with, for instance, conventional surface plasmon resonance, is investigations of the influence of nanoscale geometry on biomole...
Article
In recent years there has been a growing interest in the use of plasmonic nanostructures for color generation, a technology that dates back to ancient times. Plasmonic structural colors have several attractive features but once the structures are prepared the colors are normally fixed. Lately, several concepts have emerged for actively tuning the c...
Article
Full-text available
Biosensors based on plasmonic nanostructures offer label-free and real-time monitoring of biomolecular interactions. However, so do many other surface sensitive techniques with equal or better resolution in terms of surface coverage. Yet, plasmonic nanostructures offer unique possibilities to study effects associated with nanoscale geometry. In thi...
Article
Polymer brushes are widely used as surface coatings for various inert, functional, or responsive interfaces. If the polymer can alter its protonation state (a polyelectrolyte (PE)), the brush can switch between a collapsed and swollen state with pH, which enables applications such as nanoscale actuators. However, changes in brush height as the poly...
Article
Antibody-antigen interactions are complex events central to immune response, in vivo and in vitro diagnostics, and development of therapeutic substances. We developed an ultrastable single-molecule localized surface plasmon resonance (LSPR) sensing platform optimized for studying antibody-antigen interaction kinetics over very long time scales. The...
Article
Full-text available
Control of molecular translocation through nanoscale apertures is of great interest for DNA sequencing, biomolecular filters, and new platforms for single molecule analysis. However, methods for controlling the permeability of nanopores are very limited. Here, we show how nanopores functionalized with poly(ethylene glycol) brushes, which fully prev...
Article
Nanoplasmonic sensors have emerged as a promising measurement approach to track biomacromolecular interactions involving lipid membrane interfaces. By taking advantage of nanoscale fabrication capabilities, it is possible to design sensing platforms with various architectural configurations. Such capabilities open the door to fabricating lipid memb...
Article
Full-text available
Polymer brushes are widely used to prevent adsorption of proteins, but the mechanisms by which they operate remain heavily debated since many decades. We show conclusive evidence that a polymer brush can be a remarkably strong kinetic barrier towards proteins by using poly(ethylene glycol) grafted to the sidewalls of pores in 30 nm thin gold films....
Chapter
During the last 20 years, the use of nanopore membranes to separate molecules depending on their size, charge or other characteristics, have increased in interest. These more ordered and defined nanopores have several advantages compared to traditional ultrafiltration membranes and provide possibilities to combine with, e.g., both electrical and op...
Article
Poly(ethylene glycol) (PEG) is widely used in biotechnology-related applications yet its temperature-dependent functionality is not well understood. Here, we use bovine serum albumin (BSA) monomers and cross-linked dimers to directly probe the height of strongly stretched PEG brushes using surface plasmon resonance (SPR) in aqueous solution. Our re...
Article
Plasmonic color generation offers several advantages but is also limited by the cost and availability of noble metals like gold. In this work we present color-tuneable metasurfaces with high chromaticity and reflectivity consisting of an aluminum mirror, a dielectric spacer and a plasmonic nanohole array in copper. Copper is shown to be an excellen...
Article
Full-text available
Plasmonic nanostructures are widely used for various sensing applications by monitoring changes in refractive index through optical spectroscopy or as substrates for surface enhanced Raman spectroscopy. However, in most practical situations conventional surface plasmon resonance is preferred for biomolecular interaction analysis because of its high...
Article
Full-text available
Localized surface plasmon resonance (LSPR) biosensing based on supported metal nanoparticles offersunparalleled possibilities for high-end miniaturization, multiplexing and high-throughput label-free molecular interaction analysis in real time when integrated within an opto-fluidic environment. However, such LSPR sensing devices typically contain e...
Article
Polymerization from surfaces and the resulting “brushes” have many uses in the development of novel materials and functional interfaces. However, it is difficult to accurately monitor the polymerization rate, which limits the use of polymer brushes in applications where control of thickness is desirable. We present a new methodology based on angula...
Article
method provides high polarization-independent resonant reflection (>90% in air), good contrast (30–50%), fast response times (ms regime), ultralow power consumption (<0.5 mW cm −2), and long-term stability. We also show that plasmonic metasur-faces containing pixels of the primary colors red–green–blue (RGB) give the same reflectivity and contrast...
Article
Accurate concentration determination of subpopulations of extracellular vesicles (EVs), such as exosomes, is of importance both in the context of understanding their fundamental biological role and of potentially using them as disease biomarkers. In principle, this can be achieved by measuring the rate of diffusion-limited mass uptake to a sensor s...
Article
Plasmonic nanohole arrays are widely used for optical label-free molecular detection. An important factor for many applications is the diameter of the apertures. So far nanohole arrays with controllable diameters below 100 nm have not been demonstrated and it has not been systematically investigated how the diameter influences the optical propertie...
Article
Full-text available
The biochemical processes of cell membranes are sensitive to the geometry of the lipid bilayer. We show how plasmonic "nanowells" provide label-free real-time analysis of molecules on membranes with detection of preferential binding at negative curvature. It is demonstrated that norovirus accumulate in invaginations due to multivalent interactions...
Article
Emission of photoexcited hot electrons from plasmonic metal nanostructures to semiconductors is key to a number of proposed nanophotonics technologies for solar harvesting, water splitting, photo catalysis and a variety of optical sensing and photodetector applications. Favorable materials and catalytic properties make systems based on gold and TiO...
Article
Full-text available
We present a new grafting-to method for resistant "non-fouling" poly(ethylene glycol) brushes, which is based on grafting of polymers with reactive end groups in 0.9 M Na2SO4 at room temperature. The grafting process, the resulting brushes and the resistance towards biomolecular adsorption are investigated by surface plasmon resonance, quartz cryst...
Article
A review of sensing applications based on plasmonic nanopores is given. Many new types of plasmonic nanopores have recently been fabricated, including pores penetrating multilayers of thin films, using a great variety of fabrication techniques based on either serial nanolithography or self-assembly. One unique advantage with nanopores compared to o...
Article
We evaluate and compare the sensitivity of gold nanodisks on silica substrates and nanoholes made in silica-supported gold films, two of the most common sensor structures used in plasmonic biosensing. An alumina overcoat was applied by atomic layer deposition (ALD) to precisely control the interfacial refractive index and determine the evanescent p...
Article
A novel type of plasmonic nanopore array in a metal–insulator–metal thin film is presented. The optical properties of this structure are described using a generic theoretical framework for surface waves in a coupled multilayer system. The characteristic spacing (short-range order) of the pores enables grating-type coupling to hybridized surface pla...
Article
We have created a simple and efficient thermal plasmonic sensor platform by letting a DC current heat plasmonic nanohole arrays. This sensor can be used to determine thermodynamic parameters in addition to monitoring molecular reactions in real-time. We use the thermal sensor to determine the kinetics and activation energy for desorption of thiol m...
Article
The sensitivity of a surface plasmon to the dielectric environment makes it a viable tool in detecting single molecules. To be able to precisely determine sensed molecular concentrations and carry out precise analyses of single-molecule binding/unbinding events in real time it is necessary to quantify rigorously the relation between the number of b...
Article
We introduce a novel optical biosensing platform that exploits the asymmetry of embedded nanostructures, termed nanomenhirs. Upon oblique illumination using plane polarized white light, two plasmonic resonances attributable to the bases and the axes of the nanomenhirs emerge; these are used for location-specific sensing of membrane-binding events....
Article
Full-text available
Optical biosensors based on surface plasmon resonance (SPR) in metallic thin films are currently standard tools for measuring molecular binding kinetics and affinities - an important task for biophysical studies and pharmaceutical development. Motivated by recent progress in the design and fabrication of metallic nanostructures, such as nanoparticl...
Article
Simultaneous LSPR and electronic sensing of potential induced ion adsorption onto gold nanowire arrays is presented. The formation of a Stern layer upon applying an electrochemical potential generated a complex optical response. Simulation of a lossy atomic layer on the nanowire array using the Multiple Multipole Program (MMP) corresponded very wel...
Article
Nanoholes with short-range ordering were fabricated in ultrathin aluminum/aluminum nitride multilayer films where each layer is as thin as a few nanometers. Optical resonances of the trilayer system with a single metallic layer and five-layer system with two metallic layers were successfully tuned in the visible-near-infrared (vis/NIR) range. The r...
Chapter
This consistent and systematic review of recent advances in optical antenna theory and practice brings together leading experts in the fields of electrical engineering, nano-optics and nano-photonics, physical chemistry and nanofabrication. Fundamental concepts and functionalities relevant to optical antennas are explained, together with key princi...
Article
Full-text available
There is no doubt that the recent advances in nanotechnology have made it possible to realize a great variety of new sensors with signal transduction mechanisms utilizing physical phenomena at the nanoscale. Some examples are conductivity measurements in nanowires, deflection of cantilevers and spectroscopy of plasmonic nanoparticles. The fact that...
Article
We present the fabrication and optical characterization of plasmonic nanostructures consisting of nanohole arrays in two thin films, a metal and a dielectric. A novel method called mask-on-metal colloidal lithography is used to prepare high aspect ratio holes, providing efficient mass fabrication of stable structures with close to vertical walls an...
Chapter
This chapter aims to give an overview of how to optimize the performance of nanoplasmonic sensors. Specific biosensing challenges beyond the capability of current nanoplasmonic sensors will be discussed. Various methods to improve sensor performance will then be introduced, including solving issues related to surface chemistry. We distinguish the c...
Chapter
This chapter is dedicated to nanoplasmonic sensing systems made compatible with studies of artificial cell membranes. After a short motivation to the opportunity of sensors designed for such studies to fill an existing technological gap, we introduce basic features of cell membranes and common mimics of the cell membrane that have been proven usefu...
Article
Many nanotechnological devices are based on implementing electrochemistry with plasmonic nanostructures, but these systems are challenging to understand. We present a detailed study of the influence of electrochemical potentials on plasmon resonances, in the absence of surface coatings and redox active molecules, by synchronized voltammetry and spe...
Book
The book presents an integrated view of plasmonic biosensors that operate by refractometric detection. This means that analyte binding to the sensor surface induces a local change in refractive index, which alters the far field spectrum, as detected by optical spectroscopy. Other plasmonic biosensors such as those based on coupling between suspende...
Article
The enormous progress of nanotechnology during the last decade has made it possible to fabricate a great variety of nanostructures. On the nanoscale, metals exhibit special electrical and optical properties, which can be utilized for novel applications. In particular, plasmonic sensors including both the established technique of surface plasmon res...
Article
Biosensing with nanoholes is one of the most promising applications of nanoplasmonic devices. The sensor properties, however, are complex due to coupled resonances through propagating and localized surface plasmons. This Full Paper demonstrates experimental and simulation studies on different plasmonic hole systems, namely various patterns of circu...
Article
We show how gold recrystallizes when under the influence of electrochemical potentials. This "cold annealing" occurs without charge transfer reactions and preserves nanoscale structural features. By performing the process on plasmonic nanostructures, grain growth is monitored noninvasively by optical spectroscopy. In this way, the influence from cr...
Article
Nanoplasmonic sensors based on short-range ordered nanoholes in thin metal films and discrete metal nanoparticles are known to provide similar sensing performance. However, a perforated metal film is unique in the sense that the holes can be designed to penetrate through the substrate, thereby also fulfilling the role of nanofluidic channels. This...
Article
The optical signal of a localized surface plasmon resonance (LSPR)-based sensor combined with electrochemistry was investigated. Gold nanoparticles were immobilized on an indium tin oxide (ITO) substrate, which functioned as working electrode. Using cyclic voltammetry synchronized with LSPR sensing, surface reactions on gold were detected both elec...
Article
In this article, we demonstrate how to perform microscale spectroscopy of plasmonic nanostructures in order to minimize the noise when determining the resonance peak wavelength. This is accomplished using an experimental setup containing standard optical components mounted on an ordinary light microscope. We present a detailed comparison between ex...
Article
Susceptibility to norovirus infection has been linked to secretor status. Norovirus virus-like particles (VLPs; 0- 20 microg/mL) from the Norwalk (GI.1) and Dijon (GII.4) strains were assayed for binding to H type 1 and Lewis a pentaglycosylceramides, incorporated in laterally fluid supported lipid bilayers. Binding kinetics was monitored in real t...
Article
We present a method providing synchronized measurements using the two techniques: quartz crystal microbalance with dissipation (QCM-D) monitoring and localized surface plasmon resonance (LSPR). This was achieved by letting a thin gold film perforated with short-ranged ordered plasmon-active nanoholes act as one of the electrodes of a QCM-D crystal....
Article
Full-text available
The resonance conditions for excitation of propagating surface plasmons at planar metal/dielectric interfaces and localized surface plasmons associated with metal nanostructures are both sensitive to changes in the interfacial refractive index. This has made these phenomena increasingly popular as transducer principles in label-free sensing of biom...
Article
Full-text available
This article summarizes our most recent contributions to the rapidly growing field of supported lipid assemblies with emphasis on current studies addressing both fundamental and applied aspects of supported lipid bilayer (SLB) and tethered lipid vesicles (TLVs) to be utilized in sensing applications. The new insights obtained from combining the qua...
Article
A study was conducted to investigate specific self-assembly of single lipid vesicles in nanoplasmonic apertures in gold. The study used quartz crystal microbalance (QCM) technique to determine the thiol-based surface modifications of gold. The study also used a colloidal lithography to produce distributed apertures in a Au film on a thick cover gla...
Article
Full-text available
We report the use of individual gold nanorods as plasmonic transducers to detect the binding of streptavidin to individual biotin-conjugated nanorods in real time on a surface. Label-free detection at the single-nanorod level was performed by tracking the wavelength shift of the nanorod-localized surface plasmon resonant scattering spectrum using a...
Article
This paper presents the use of the localized surface plasmon resonance (LSPR) sensor concept to probe the formation of macroscopic and laterally mobile supported lipid bilayers (SLBs) on SiOx-encapsulated nanohole-containing Au and Ag films. A comparison between Au- and Ag-based sensor templates demonstrates a higher sensitivity for Au-based templa...