Christian Kuttner

Nature Communications

We studied the controlled growth of triangular prismatic Au nanoparticles with different beveled sides for surface-enhanced Raman spectroscopy (SERS) applications. First, in a seedless synthesis using 3-butenoic acid (3BA) and benzyldimethylammonium chloride (BDAC), gold nanotriangles (AuNTs) were synthesized in a mixture with gold nanooctahedra (A...

The optical properties of nanoparticle assemblies can be tailored via hybridization of plasmon modes. Isotropic core/satellite superstructures made of spherical nanoparticles are known to exhibit coupled modes with a strongly scattering (radiative) character, which provide hot-spots yielding high activity in surface-enhanced Raman scattering (SERS)...

Superstructures of gold nanospheres offer augmented surface-enhanced Raman scattering (SERS) activities beyond the limits of their individual building blocks. However, for application as reliable and quantitative colloidal SERS probes, some key aspects need to be considered to combine efficiency and robustness with respect to hotspot excitation, an...

Lattice plasmons, i.e., diffractively coupled localized surface plasmon resonances, occur in long‐range ordered plasmonic nanostructures such as 1D and 2D periodic lattices. Such far‐field coupled resonances can be employed for ultrasensitive surface‐enhanced Raman spectroscopy (SERS), provided they are spectrally matched to the excitation waveleng...

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Inside Front Cover In article number 2100453, Kuttner, Liz-Marzán, Seifert and co-workers demonstrate mechano-optical nanostructures with reversibly tunable lattice-plasmon resonances consisting of self-assembled superlattices on stretchable substrates. Macroscopic mechanical strain allows a single lattice structure to be adapted to both red-shifte...

The use of light as an external stimulus to control the enzyme activity is an emerging strategy that enables accurate, remote, and noninvasive biotransformations. In this context, immobilization of enzymes on plasmonic nanoparticles offers an opportunity to create light-responsive biocatalytic materials. Nevertheless, a fundamental and mechanistic...

The image artistically illustrates the interaction of light with a colloidal superstructure of a triangulated core decorated with gold nanoparticles. Besides the excitation of hotspots at the so-called satellite particles, the pronounced diffuse scattering is portrayed, which is characteristic for larger core particles above 100 nm is size. (https...

The design of colloidal nanostructures as surface-enhanced Raman scattering (SERS) substrates requires control over both structural and optical characteristics. A widespread expectation is that the SERS efficiency depends crucially on whether the plasmonic excitation matches the exciting laser wavelength. However, also the balance between radiative...

Progress of thermal tumor therapies and their translation into clinical practice are limited by insufficient nanoparticle concentration to release therapeutic heating at the tumor site after systemic administration. Herein, the use of Janus magneto‐plasmonic nanoparticles, made of gold nanostars and iron oxide nanospheres, as efficient therapeutic...

Bimetallic gold–palladium particles were originally proposed as catalysts with tunable reaction rates. Following the development of synthesis routes that offer better control on the morphology and composition of the particles, novel optical sensing functionalities were more recently proposed. Since temperature is a fundamental parameter that interp...

We present hybrid systems bearing both plasmonic colloids and redox-active molecules that have demonstrated excellent performances in the catalytic reduction of nitrophenol (Nip) to aminophenol (Amp) in the presence of sodium borohydride. First, amino-functionalized spherical and triangular gold nanoparticles (AuNSs and AuNTs, respectively) were co...

We present a process to create flexible 2D superlattices of nanoparticles, self-assembled into discrete and long-range ordered clusters. The process is readily scalable and grants access to mechano-responsive nanostructures on square centimeter areas. The elastic properties of the support allow for post-assembly tailoring of the lattice periodicity...

This chapter gives a brief overview of plasmonic nanoparticle (NP)-based sensing concepts ranging from classical spectral-shift colorimetry to the highly active field of surface-enhanced Raman scattering (SERS) spectroscopy. In the last two decades, colloidal approaches have developed significantly. This is seen with, for example, refractive-index...

Smart polymers are a valuable platform to protect and control the activity of biological agents over a wide range of conditions, such as low pH, by proper encapsulation. Such conditions are present in olive oil mill wastewater with phenol as one of the most problematic constituents. We show that elastic and pH-responsive diblock copolymer fibers ar...

We investigate the plasmonic coupling of metallic nanoparticles with continuous metal films by studying the effect of particle-to-film distance, cavity geometry and particle size. To efficiently screen these parameters, we fabricated a particle-to-film coupled functional nanostructure for which particle size and distance vary. We use gold-core/poly...

Nanorattles are metallic core-shell particles with core and shell separated by a dielectric spacer. These nanorattles have been identified as a promising class of nanoparticles, due to their extraordinary high electric-field enhancement inside the cavity. Limiting factors are reproducibility and loss of axial symmetry owing to the movable metal cor...

Diamond tools are essential in various industries. The high hardness of diamond enables the machining of a wide range of different materials. The materials processed with diamond cutting tools vary from ceramic or metal components to natural materials like stone. In most cases, the abrasive diamonds of such cutting tools are embedded in a metal mat...

One of the key challenges in two-dimensional (2D) materials is to go beyond graphene, a prototype 2D polymer (2DP), and to synthesize its organic analogues with structural control at the atomic- or molecular-level. Here we show the successful preparation of porphyrin-containing monolayer and multilayer 2DPs through Schiff-base polycondensation reac...

Carbon/Carbon (C/C) composites derived from the thermoplastic polymer polyetherimide (PEI) were pyrolized up to 1000 °C, subsequently carbonized in inert atmosphere up to 2200 °C and afterwards infiltrated with liquid silicon. The investigation of fibers and matrix with Raman microspectroscopy revealed, that an increased carbonization temperature l...

This chapter focuses on decorating nanoparticles with synthetic as well as biomacromolecules for controlling interparticle distances and relative orientations in assemblies. It introduces synthetic approaches toward core/shell architectures and shows how macromolecular ligands allow controlling order in 2D and 3D assemblies. The chapter illustrates...

We present a bottom-up assembly route for a large-scale organization of plasmonic nanoparticles (NPs) into three-dimensional (3D) modular assemblies with core/satellite structure. The protein-assisted assembly of small spherical gold or silver NPs with a hydrophilic protein shell (as satellites) onto larger metal NPs (as cores) offers high modulari...

We demonstrate a template-assisted colloidal self-assembly approach for magnetic metasurfaces on macroscopic areas. The choice of anisotropic colloidal particle geometry, assembly pattern and metallic film is based on rational design criteria, taking advantage of mirror-charge effects for gold nanorods placed on gold film. Monodisperse gold nanorod...

Hybrid composites containing endless glass fiber reinforcement and surface functionalized carbon nanotubes (CNTs) dispersed in the matrix phase were produced by resin transfer molding (RTM). An efficient surface modification of the nanotubes enhances the compatibility with the matrix system and the dispersion quality, enabling the impregnation proc...

A low volume shrinkage vinylcyclopropane (VCP) monomer, showing both a high reactivity and a low viscosity, was obtained by applying a sterically hindered and isomeric spacer element, incorporating intermolecular amide hydrogen bonds. The resulting properties locate this VCP system in a pronounced range that so far no other efficient and radical po...

Figure: Surface coupled gold nanorods as building blocks on the macroscopic area using template assisted assembly technique. (a) Protein stabilized gold nanorods. The BSA corona is highlighted in green on TEM image. (b) Schematic description of wrinkle formation via oxygen plasma of a stretched PDMS substrate (template). (c) TEM image of printed go...

We investigate the effect of surfactant-mediated, asymmetric silver overgrowth of gold nanorods on their intrinsic optical properties. From concentration-dependent experiments, we established a close correlation of the extinction in the UV/vis/NIR frequency range and the morphological transition from gold nanorods to Au@Ag cuboids. Based on this co...

We present the surfactant-controlled overgrowth of gold nanorods into gold-core silver-shell nanoparticles (rodboids) to gain low growth rates for full control of the kinetic process. In gold-core silver-shell rodboids not much attentions has been paid to the overlap region of the intra-band gaps of gold and silver (326 to 515 nm). In this optical...

We present ensembles of gold nanoparticle arranged in single and double lines on solid substrates.[1] These linear assemblies were formed by template-assisted self-assembly[2,3] of monodisperse protein-coated gold nanoparticles in wrinkle templates. The substrates exhibit high structural regularity on centimeter-squared areas which allow for charac...

We demonstrate a novel approach for controlling the formation of line-defects in wrinkling patterns by introducing step-like changes in the Young’s modulus of elastomeric substrates supporting thin, stiff layers. Wrinkles are formed upon treating the poly(dimethylsiloxane) (PDMS) substrates by UV/Ozone (UVO) exposure in uniaxially stretched state a...

We present the surfactant-controlled overgrowth of gold nanorods into gold-core silver-shell nanoparticles (Au@Ag cuboids) to gain low growth rates for full control of the kinetic process. Our results provide the basis for tailored cubic silver shells with ultra-sharp corners, which may find application as building blocks with intrinsic optical met...

In this work, we investigate the ligand exchange of cetyltrimethylammonium bromide (CTAB) with bovine serum albumin for gold nanorods. We demonstrate by surface-enhanced Raman scattering measurements that CTAB, which is used as a shape-directing agent in the particle synthesis, is completely removed from solution and particle surface. Thus, the pro...

We demonstrate the large-scale organisation of anisotropic nanoparticles into linear assemblies displaying optical anisotropy on macroscopic areas. Monodisperse gold nanorods with a hydrophilic protein shell are arranged by dip-coating on wrinkled surfaces and subsequently transferred to indium tin oxide (ITO) substrates by capillary transfer print...

This thesis explores macromolecular interphases and interfaces in synthetic fiber-reinforced composite materials and supracolloidal core/shell objects. Every composite exhibits system-specific boundaries, either distinct (interface) or diffuse (interphase), which are responsible for properties like elasticity, stability, compatibility, or in genera...

We present ensembles of surface-ordered nanoparticle arrangements, which are formed by template-assisted self-assembly of monodisperse, protein-coated gold nanoparticles in wrinkle-templates. Centimeter square areas of highly regular, linear assemblies with tunable line width are fabricated and their extinction cross-sections can be characterized b...

We present a versatile approach to produce macroscopic, substrate-supported arrays of plasmonic nanoparticles with well-defined interparticle spacing and a continuous particle size gradient. The arrays thus present a "plasmonic library" of locally non-coupling plasmonic particles of different sizes, which can serve as a platform for future combinat...

The increasing demand in fiber-reinforced plastics (FRPs) necessitates economic processing of high quality, like the vacuum-assisted resin transfer molding (VARTM) process. FRPs exhibit excellent in-plane properties but weaknesses in off-plane direction. The addition of nanofillers into the resinous matrix phase embodies a promising approach due to...

Many technical applications make use of composite materials, which for good performance require specific interfacial properties between their constituents. Thus, polymeric modifications are desirable for interface engineering. We developed a direct photocoating process based on surface-initiated thiol-ene chemistry without the need for additional p...

Many technical applications utilize composite materials, which require specific interfacial properties between their constituents in order to perform well. Thus polymeric modifications are desirable for interface engineering. We developed a photocoating process based on surface-initiated thiol-ene photochemistry without the need for additional phot...

Plasmonic nanoparticle arrays are excellent candidates for their potential use in optical devices such as sensors, waveguides, or photovoltaic cells. Their electromagnetic behavior is highly dependent on their specific particle size, shape, and surrounding environment. However, the lack of capability to form reproducible organized structures is sti...

This thesis explores macromolecular interphases and interfaces in synthetic fiber-reinforced composite materials and supracolloidal core/shell objects. Every composite exhibits system-specific boundaries, either distinct (interface) or diffuse (interphase), which are responsible for properties like elasticity, stability, compatibility, or in genera...

This work presents the modification of polyorganosiloxane microparticles by surface-initiated thiol-ene photochemistry. By this photocoating, we prepared different core/shell particles with a polymeric shell within narrow size-distributions (PDI = 0.041-0.12). As core particle, we used highly monodisperse spherical polyorganosiloxane particles prep...