 Authenticating system |
| In accordance with the invention, there is provided, a system for authenticating a substrate, ... |
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| Capillary for electrospray ion source |
| Capillaries according to the present invention may be made with such dimensions and proportions as ... |
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| Photodiode light sensor |
| What is claimed is: 1. A light sensor comprising: a photodiode light transducer exposed to light, ... |
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| Homogeneous coordination compounds as oxidation catalysts |
| OF THE INVENTION The transition metal oxidizing agents have both sigma bonds and weak pi bonds. T... |
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| Reductive alkylation of secondary amines with hydrosilane |
| OF THE INVENTION In its broadest aspect, the present invention provides a more efficient process ... |
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| Process for the conversion of 3-methyl-3-hydroxycepham compounds |
| OF THE INVENTION The process of this invention is carried out by heating a 7-imido-3.alpha.-methyl-... |
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| 3-Alkylsilyl-2-oxazolidonone compounds and synthesis thereof |
| OF THE INVENTION EXAMPLE I. 3-trimethylsilyl-2-oxazolidinone (TMSO) Triethylamine (60 ml; 0.42 mol)... |
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Electrochemical sensor
| Details |
Inventors: Hintsche, Rainer; Paeschke, Manfred; Schnakenberg, Uwe; Wollenberger, Ulla;
Assignee: Fraunhofer-Gesellschaft zur angewandten Forschung e.V. (Munich, DE)
Primary Examiner: Bell; Bruce F.
Assistant Examiner:
Attorney, Agent or Firm: Hormann; Karl
The invention relates to an electrochemical sensor with interdigital micro-electrodes (1) with structure widths in the sub-.mu.m range. With a twin or multi-pair array of the interdigital micro-electrodes on a substrate (8), the electrochemical detection of molecules with high sensitivity is made possible and further uses for the detection of chemical reaction cycles are made available. The electrodes may be arranged in a micro-channel applied to the substrate having a constant small volume of a few nanoliters. The electrochemical sensor of the invention is suitable for the multiple measurement of the same species of molecule or as a multi-sensitive sensor in chemical analysis and process control in various fields such as biotechnology, environmental protection or health. |
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DETAILED DESCRIPTION It is a task of the invention to provide an electrochemical sensor which makes electrochemical detection of molecules possible at a higher detection sensitivity and which offers enhanced possibilities of use for detecting chemical reaction processes.
This task is solved, in general, by an electrochemical sensor provided with two or more pairs of interdigitated micro-electrodes of structural widths less than 1 .
mu.
m.
The micro-electrodes are arranged as an array on a substrate.
The individual pairs may be energized independently of each other with electric potentials, and the measurement effects at the individual electrodes can be drained or derived independently.
In the present context, measurement effects are understood to be, in particular, amperometric, potentiometric or impedimetric effects.
The preferred planar substrate used is glass, sapphire, silicon or polymers, with the electrodes being applied by planar technology.
The fine geometry structuring of the electrodes results in spaces (e.
g.
distances of about 700 nm) between the interdigitated micro-electrodes, i.
e.
electrodes arranged in a finger-like pattern, which are small relative to the distances traveled by the molecules to be detected, in the measuring time.
Thus, it becomes possible electrochemically to capture the same molecule several times, as, for example, for repeatedly oxidizing and reducing it before it diffuses out of the range of the electrodes.
In this manner, particularly advantageous amplification effects are obtained.
The multiple arrangement of finely structured pairs of electrodes in accordance with the invention advantageously leads to a multiplication of the amplification effect just described, by realizing, with an appropriate multiple electrode measuring technique (e.
g.
with a computer-assisted multi-potentiometer) simultaneous measurements as well as the renewed capture of molecule species which had previously been made at a neighboring interdigitated electrode pair.
Simultaneous measurement and recapture lead to a significant improvement in the analytical detection sensitivity
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Semiconductor manufacture 
