Scientific and practical applications of supported lipid-protein bilayers are described. Membranes can be covalently coupled to or separated from solids by ultrathin layers of water or soft polymer cushions. The latter systems maintain the structural and dynamic properties of free bilayers, forming a class of models of biomembranes that allow the application of a manifold of surface-sensitive techniques. They form versatile models of low-dimensionality complex fluids, which can be used to study interfacial forces and wetting phenomena, and enable the design of phantom cells to explore the interplay of lock-and-key forces (such as receptor-ligand binding) and universal forces for cell adhesion. Practical applications are the design of (highly selective) receptor surfaces of biosensors on electrooptical devices or the biofunctionalization of inorganic solids.

https://science.sciencemag.org/content/sci/271/5245/43.full.pdf

Supported Membranes: Scientific and Practical Applications

Conventional approaches to chemical sensors have
traditionally made use of a “lock-and-key” design,
wherein a specific receptor is synthesized in order to
strongly and highly selectively bind the analyte of
interest.1-6 A related approach involves exploiting a
general physicochemical effect selectively toward a
single analyte, such as the use of the ionic effect in
the construction of a pH electrode. In the first
approach, selectivity is achieved through recognition
of the analyte at the receptor site, and in the second,
selectivity is achieved through the transduction
process in which the method of detection dictates
which species are sensed. Such approaches are appropriate
when a specific target compound is to be
identified in the presence of controlled backgrounds
and interferences. However, this type of approach
requires the synthesis of a separate, highly selective
sensor for each analyte to be detected. In addition,
this type of approach is not particularly useful for
analyzing, classifying, or assigning human value
judgments to the composition of complex vapor
mixtures such as perfumes, beers, foods, mixtures of
solvents, etc.

/pdf/cross-reactive-chemical-sensor-arrays-38dz1buu0b.pdf

Cross-reactive chemical sensor arrays.

The invention provides methods of detecting a nucleic acid. The methods comprise contacting the nucleic acid with one or more types of particles having oligonucleotides attached thereto. In one embodiment of the method, the oligonucleotides are attached to nanoparticles and have sequences complementary to portions of the sequence of the nucleic acid. A detectable change (preferably a color change) is brought about as a result of the hybridization of the oligonucleotides on the nanoparticles to the nucleic acid. The invention also provides compositions and kits comprising particles. The invention further provides methods of synthesizing unique nanoparticle-oligonucleotide conjugates, the conjugates produced by the methods, and methods of using the conjugates. In addition, the invention provides nanomaterials and nanostructures comprising nanoparticles and methods of nanofabrication utilizing nanoparticles. Finally, the invention provides a method of separating a selected nucleic acid from other nucleic acids.

Nanoparticles having oligonucleotides attached thereto and uses therefor

http://cau.ac.kr/~jjang14/BioMEMS/Bashir_ADDR_Reviews_BioMEMS_2004.pdf

BioMEMS: state-of-the-art in detection, opportunities and prospects

A bulk-doped semiconductor that is at least one of the following: a single crystal, an elongated and bulk-doped semiconductor that, at any point along its longitudinal axis, has a largest cross-sectional dimension less than 500 nanometers, and a free-standing and bulk-doped semiconductor with at least one portion having a smallest width of less than 500 nanometers. Such a semiconductor may comprise an interior core comprising a first semiconductor; and an exterior shell comprising a different material than the first semiconductor. Such a semiconductor may be elongated and may have, at any point along a longitudinal section of such a semiconductor, a ratio of the length of the section to a longest width is greater than 4:1, or greater than 10:1, or greater than 100:1, or even greater than 1000:1. At least one portion of such a semiconductor may a smallest width of less than 200 nanometers, or less than 150 nanometers, or less than 100 nanometers, or less than 80 nanometers, or less than 70 nanometers, or less than 60 nanometers, or less than 40 nanometers, or less than 20 nanometers, or less than 10 nanometers, or even less than 5 nanometers. Such a semiconductor may be a single crystal and may be free-standing. Such a semiconductor may be either lightly n-doped, heavily n-doped, lightly p-doped or heavily p-doped. Such a semiconductor may be doped during growth. Such a semiconductor may be part of a device, which may include any of a variety of devices and combinations thereof, and a variety of assembling techniques may be used to fabricate devices from such a semiconductor. Two or more of such a semiconductors, including an array of such semiconductors, may be combined to form devices, for example, to form a crossed p-n junction of a device. Such devices at certain sizes may exhibit quantum confinement and other quantum phenomena, and the wavelength of light emitted from one or more of such semiconductors may be controlled by selecting a width of such semiconductors. Such semiconductors and device made therefrom may be used for a variety of applications.

Doped elongated semiconductors, growing such semiconductors, devices including such semiconductors, and fabricating such devices

An array of closely spaced interdigitated microelectrodes was applied to the sensitive detection of reversible redox couples. The measurement is based on the redox cyclization between the adjacent microband electrodes of the interdigitated array (IDA), when both the respective oxidation and reduction potential are applied at the electrode pairs. The multiple oxidation and reduction result in an increased generation of current. The steady-state current of mediators, such as phenazine methosulfate, hexacyanoferrate(II), pyrocatechol, benzoquinone and p-aminophenol, was amplified by a factor of 10–20 compared with the current of single electrodes. The high collection efficiency enabled this signal amplification rate to be obtained. The detection limit for p-aminophenol was 100 nmol l–1. The IDA sensor was applied to the determination of alkaline phosphatase and β-galactosidase activity by detecting enzymatically generated p-aminophenol.

Interdigitated array microelectrodes for the determination of enzyme activities

Properties of interdigital electrode arrays with different geometries

Microelectrode arrays and application to biosensing devices

A modular voltammetric multichannel detection system has been developed for use in flow analysis. Two different types of multichannel potentiostats, an adjustable and a ground-fixed potentiostat, are realized. Both types work with up to sixteen independent working electrodes at one chip electrode array and are controlled through a personal computer and a microcontroller. Simultaneous difference pulse and cyclic voltammetric procedures are realized. Platinum thin-film array electrodes have been arranged on silicon wafers as pairs of interdigitated microband electrodes (interdigitated array electrodes; IDA) with an interelectrode gap in the submicrometer range. Furthermore the multichannel electrodes in a flow system were used to characterize the highly sensitive flow profiles and flow rate measurements using redox mediators. A brief description of applying the multichannel device for ‘window’ stripping of heavy metals is given.

Voltammetric multichannel measurements using silicon fabricated microelectrode arrays

The invention relates to a method for reading at least one attribute stored in an ID token, wherein the ID token is assigned to a user, comprising the following steps: authenticating the user with respect to the ID token, authenticating a first computer system with respect to the ID token, after successful authentication of the user and the first computer system with respect to the ID token, read-access by the first computer system to the at least one attribute stored in the ID token for transfer of the at least one attribute to a second computer system.

Manfred Paeschke

Papers

Interdigitated array microelectrodes for the determination of enzyme activities

Properties of interdigital electrode arrays with different geometries

Microelectrode arrays and application to biosensing devices

Voltammetric multichannel measurements using silicon fabricated microelectrode arrays

Method for reading attributes from an ID token