Showing papers by "Matthias Meyer published in 2006"
TL;DR: A simple analytic model for the optical properties of gold is proposed, which includes a minimum set of parameters necessary to represent the complex dielectric function of gold in the visible and near-uv regions.
Abstract: A simple analytic model for the optical properties of gold is proposed. The model includes a minimum set of parameters necessary to represent the complex dielectric function of gold in the visible and near-uv regions. Explicit values for the parameters to reproduce the Johnson and Christy data [Phys. Rev. B 6, 4370 (1972)] on the optical properties of gold are provided.
662 citations
TL;DR: A method is proposed to pin down unambiguous proof for single-molecule sensitivity in surface enhanced Raman spectroscopy (SERS) using the simultaneous use of two analyte molecules, which eliminates most of the uncertainties associated with low dye concentrations in previous experiments.
Abstract: A method is proposed to pin down unambiguous proof for single-molecule sensitivity in surface enhanced Raman spectroscopy (SERS). The simultaneous use of two analyte molecules enables a clear confirmation of the single (or few)-molecule nature of the signals. This method eliminates most of the uncertainties associated with low dye concentrations in previous experiments. It further shows that single- or few-molecule signals are very common in SERS, both in liquids and on dry substrates.
499 citations
TL;DR: In this article, the authors provide a theoretical framework to understand the phenomenology and statistics of single molecule signals arising in surface enhanced Raman scattering (SERS) under the presence of so-called electromagnetic hot spots.
Abstract: We provide the theoretical framework to understand the phenomenology and statistics of single molecule (SM) signals arising in surface enhanced Raman scattering (SERS) under the presence of so-called electromagnetic hot spots. We show that most characteristics of the SM-SERS phenomenon can be tracked down to the presence of a tail-like (power law) distribution of enhancements and we propose a specific model for it. We analyze, in the light of this, the phenomenology of SM-SERS and show how the different experimental manifestations of the effect reported in the literature can be analyzed and understood under a unified "universal" framework with a minimum set of parameters.
347 citations
TL;DR: It is shown that most characteristics of the SM-SERS phenomenon can be tracked down to the presence of a tail-like (power law) distribution of enhancements and a specific model for it is proposed.
Abstract: We provide the theoretical framework to understand the phenomenology and statistics of single-molecule (SM) signals arising in Surface-Enhanced Raman Scattering (SERS) under the presence of so-called electromagnetic hot-spots (HS's). We show that most characteristics of the SM-SERS phenomenon can be tracked down to the presence of tail-like (power law) distribution of enhancements and we propose a specific model for it. We analyze, in the light of this, the phenomenology of SM-SERS and show how the different experimental manifestations of the effect reported in the literature can be analyzed and understood under a unified ``universal'' framework with a minimum set of parameters.
298 citations
TL;DR: SERS provides a unique tool to understand, monitor, and study the onset of aggregation in colloidal silver/gold and to prove the existence of the proposed state at the boundary of colloid coalescence.
Abstract: The existence of a metastable state with limited Coulomb-blocked aggregation at the onset of instability in a colloidal solution is proposed and demonstrated both experimentally and theoretically (through Monte Carlo simulations). Such a stable state of small clusters of metallic colloids happens to be extremely important for techniques such as surface-enhanced Raman scattering (SERS), which profits explicitly from collective plasmon resonances in these clusters to boost Raman signals of specific analytes. In fact, SERS provides a unique tool to understand, monitor, and study the onset of aggregation in colloidal silver/gold and to prove the existence of the proposed state at the boundary of colloid coalescence.
93 citations
TL;DR: The ability to amplify multiple fragments simultaneously in the first step allows the generation of large amounts of sequence from rare template DNA, whereas the second nested step increases specificity and decreases amplification of contaminating DNA.
Abstract: This method is designed to assemble long, continuous DNA sequences using minimal amounts of fragmented ancient DNA as template. This is achieved by a two-step approach. In the first step, multiple fragments are simultaneously amplified in a single multiplex reaction. Subsequently, each of the generated fragments is amplified individually using a single primer pair, in a standard simplex (monoplex) PCR. The ability to amplify multiple fragments simultaneously in the first step allows the generation of large amounts of sequence from rare template DNA, whereas the second nested step increases specificity and decreases amplification of contaminating DNA. In contrast to current protocols using many template-consuming simplex PCRs, the method described allows amplification of several kilobases of sequence in just one reaction. It thus combines optimal template usage with a high specificity and can be performed within a day.
92 citations
67 citations