The capabilities of biosensors for bio-environmental monitoring have profound influences on medical, pharmaceutical, and environmental applications. This paper provides an overview on the background and applications of the state-of-the-art biosensors. Different types of biosensors are summarized and sensing mechanisms are discussed. A review of organic materials used in biosensors is given. Spe...

The formation of interface dipoles in self-assembled monolayers (SAMs) of –CH3 and –CF3 terminated short-chain alkanethiolates on Ag(111) is studied by means of density functional theory calculations. The interface dipoles are characterized by monitoring the change in the surface work function upon adsorption of the SAM. We compare results obtained for SAMs in structures with a different packin...

Surface science has made great strides towards tailoring surface properties via self-assembly of nanoscale molecular adsorbates. It is now possible to functionalize surfaces with complex biomolecules such as DNA and proteins. This brief overview shows how NEXAFS (near edge X-ray absorption fine structure spectroscopy) can be used to characterize the assembly of biological molecules at surfaces ...

The synthesis of a variety of symmetrical bis(alkyl) and bis(fluoroalkyl) disulfides as well asmixed alkyl fluoroalkyl disulfides containing ester or amide groups is described. Self-assembled monolayers of these compounds on gold formed by spontaneous adsorption from solution are studied by contact angle measurementsandpolarizedgrazing incidenceFourier transforminfraredspectroscopy (FTIR). The ...

We propose a hydrodynamic mechanism, based on the Marangoni flow, to describe growth instabilities of liquid-condensed islands in the supercooled liquid-expanded phase of two-dimensional Langmuir monolayers. This Marangoni instability is intrinsic to Langmuir monolayers and is not controlled by the expulsion of chemical impurities from the liquid-condensed phase. The hydrodynamic transport of t...

Adsorption of sulfate assists Cu monolayer underpotential deposition (upd) on Au(111) in a unique way, rendering two distinct structural stages: (i) formation of a low-density Cu phase at coverage of 2/3 ML known as the ffiffiffi 3 p ffiffiffi 3 p R30 or honeycomb phase; (ii) formation of a complete monolayer, i.e., Cu-(1 · 1) phase pseudomorphic with respect to underlying Au(111) substrate. In...

The effect of pH on the adhesion of silica and polystyrene latex nanoparticles, presenting hydroxyl and carboxyl acid surface chemistries respectively, to self-assembled monolayers (SAMs) has been investigated. The SAMs studied were 1-dodecanethiol, 11-mercaptoundecanoic acid and an original pyridine-terminated SAM. Adhesion of nanoparticles to the SAMs was found to decrease with increasing pH ...

On the example of monolayer manganites we show that the theoretical ideas developed long ago along the derivation of the spin t–J model from the Hubbard model are nowadays very helpful in strongly correlated oxides with partly filled degenerate orbitals. We analyze a realistic orbital t–J model for eg electrons in La1−xSr1+xMnO4 monolayer manganites, and discuss the evolution of spin and orbita...

IPTV, software replication, and other large scale content distribution services raise the need for fast and efficient content delivery mechanisms in underlay as well as overlay networks. Multicast, the natural approach on the network layer, has not been deployed globally, and solutions are pushed to the application layer. For a flexible, sustainable deployment the distribution mechanisms in use...

In the interpretation of scanning tunneling spectroscopy (STS) data on molecular nanostructures the tunneling conductance is often assumed to be proportional to the local density of states of the molecule. This precludes the possibility of observing negative diierential resistance (NDR). We report here the observation of NDR in the current-voltage (I-V) characteristics of a self-assembled monol...