Measuring cell and measuring field comprising measuring cells of this type, use of a measuring and use of a measuring field

DETAILED DESCRIPTION Consequently, the invention is based on the problem of providing a measuring cell and also a measuring array having measuring cells which satisfy the requirements set and are robust and universally usable.
The problem is solved by means of a measuring cell and a measuring array having the features in accordance with the independent patent claims.
Preferred refinements of the invention emerge from the dependent claims.
The measuring cell integrated into a substrate contains a sensor, also called converter element.
The converter element converts an arbitrary measurement quantity into an electrical potential.
This also includes simply transmitting an electrical potential.
In this case, the converter element may be conceived of as a series circuit of a controlled source and a capacitance.
In this case, the converter element may be designed as a customary or pH-sensitive electrode.
A pH-sensitive electrode converts the ion concentration in an aqueous solution into a charge quantity or electrical voltage or potential and thus makes it possible to determine an electrical potential in an aqueous environment.
Furthermore, an amplifier circuit connected to the sensor is arranged on the common substrate.
According to the invention, the amplifier stage is arranged in the measuring cell.
This ensures a good signal transfer, and also a good signal-to-noise ratio.
The sensitivity toward disturbing influences, e.
g.
, leakage fields and parasitic effects, is low.
On the other hand, given suitable dimensioning of the amplifier stage, the measuring cell also has a small areal requirement, so that it is also possible to achieve high packing densities of measuring cells and it is thus possible to record the potentials even of extremely small samples, in particular also in the assemblage in a spatially resolved manner with the aid of a measuring array.
The measuring cell is distinguished by stability, high electrical sensitivity and mechanical robustness.
Preferably, the input stage of the amplifier circuit in this case contains a transistor integrated on the substrate, the sensor or, if appropriate, the sample itself being at least indirectly connected to a control terminal of the transistor