Carbon Paste Internal Electrolyte for Mg2+ Selective Electrodes

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Solution Overview

Problem

Current magnesium ion selective electrodes (ISEs) suffer from weak selectivity for Mg2+ over Ca2+, leading to inaccurate magnesium detection due to interference from calcium ions, requiring complex calibration algorithms and affecting precision and accuracy.

Innovation Solution

The use of a carbon paste internal electrolyte layer in the ISEs, which includes MgCl2 salt, enhances selectivity against Ca2+, allowing for simpler calibration and improved accuracy by minimizing Ca2+ interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional internal electrolyte layers (aqueous solutions or hydrogels) are used, then the ISE structure is simple and easy to manufacture, but the selectivity for Mg2+ over Ca2+ is weak leading to inaccurate detection

Engineering Contradiction:
Improveselectivity for Mg2+ over Ca2+VSAvoidcomplexity of calibration algorithm
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the chemical composition parameters of the internal electrolyte layer by incorporating carbon paste materials with specific properties (electrical conductivity, ion transport characteristics) to enhance Mg2+ selectivity and reduce Ca2+ interference, thereby improving measurement precision without complicating the device structure

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite internal electrolyte layers combining carbon paste with other materials to achieve both high Mg2+ selectivity and simplified calibration. The composite structure leverages the unique properties of carbon paste (conductivity, ion transport) to improve measurement precision while maintaining device simplicity

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If complex calibration algorithms are used to correct Ca2+ interference, then measurement accuracy can be maintained, but the ease of operation and calibration process becomes more difficult

Engineering Contradiction:
Improveaccuracy of magnesium detectionVSAvoidsimplicity of calibration process
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

By changing the internal electrolyte composition to carbon paste-based materials, the patent inherently reduces Ca2+ interference, allowing for simpler calibration processes while maintaining high measurement accuracy. The material parameter change eliminates the need for complex correction algorithms

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If conventional internal electrolyte materials are used, then the device structure is simple, but the selectivity coefficient for Mg2+ over Ca2+ is low

Engineering Contradiction:
Improveselectivity coefficientVSAvoidstructure of internal electrolyte layer
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs composite internal electrolyte layers incorporating carbon paste materials that provide enhanced Mg2+ selectivity through their unique electrical and ion transport properties. This composite approach achieves high selectivity coefficients while maintaining relatively simple device structure

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes parameters of the internal electrolyte layer by using carbon paste with specific conductivity and ion transport characteristics, thereby achieving high selectivity coefficients without significantly complicating the overall device structure

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The carbon paste internal electrolyte layer provides significant improvement in selectivity, enabling accurate magnesium detection with minimal or no Ca2+ correction, enhancing precision and efficiency in magnesium assays.

Implementation Method 1

The internal electrolyte layer comprises a carbon paste, and further includes a MgCl2 salt dispersed in the carbon paste

Methodology Applied
Scientific EffectIon conduction: Conduction (electrical)

Implementation Method 2

The internal electrolyte layer is capable of associating with an internal reference electrode and an ion sensing membrane to form a potentiometric ion selective electrode

Methodology Applied
Scientific EffectIon exchange and selectivity: Ion Repulsion/Attraction

Data Source

PatentEP3622280B1Potentiometric ion selective electrode with an internal electrolyte layer comprising carbon paste
Publication Date: 2025.06.25 SIEMENS HEALTHCARE DIAGNOSTICS INC
  • EP3622280B1 patent drawingFigure 1
  • EP3622280B1 patent drawingFigure 2~3
  • EP3622280B1 patent drawingFigure 4~5

AI summary

Disclosed are internal electrolyte layers for ion selective electrodes, wherein the internal electrolyte layers contain carbon paste doped with a metal salt. Also disclosed are ion selective electrodes and sensor array assemblies containing the internal electrolyte layers. Also disclosed are methods of producing and using the internal electrolyte layers, ion selective electrodes, and sensor array assemblies.