Magnesium Ion Selective Electrode Calibration Reagent Stabilization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current calibration reagents for magnesium ion selective electrodes (Mg ISEs) cause rapid wetup and unstable response kinetics, leading to shortened sensor lifespan and inaccurate measurements due to the differing selectivities of calcium and magnesium ions.

Innovation Solution

Calibrate Mg ISEs using reagents with a Ca2+:Mg2+ ratio similar to that of whole blood, incorporating a pH range of 6 to 8 and poly(ethylene oxide) surfactants to stabilize the sensor and improve response kinetics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional calibration reagents with low Ca2+:Mg2+ ratio are used, then magnesium ion measurements can be performed, but the sensor exhibits rapid wetup and unstable response kinetics leading to shortened lifespan

Engineering Contradiction:
Improvesensor lifespanVSAvoidresponse stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent changes the chemical parameters of the calibration reagent, specifically adjusting the Ca2+:Mg2+ ratio to match physiological conditions (similar to whole blood), and controlling pH in the range of 6.5-7.5. This parameter optimization stabilizes the sensor response and eliminates rapid wetup, resolving the contradiction between sensor lifespan and response stability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces poly(ethylene oxide) surfactants as intermediary substances in the calibration reagent. These surfactants mediate the interaction between the sensor membrane and calibration solutions, reducing surface tension and preventing protein adsorption that causes instability. This intermediary substance stabilizes response kinetics while extending sensor lifespan.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If calibration reagents with Ca2+:Mg2+ ratio similar to whole blood are used, then response kinetics are stabilized, but reagent formulation becomes more complex

Engineering Contradiction:
Improveresponse kinetics stabilityVSAvoidreagent formulation complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent optimizes specific parameters (Ca2+:Mg2+ ratio, pH) to physiological ranges, which naturally align with blood composition. This approach stabilizes response kinetics while using biologically relevant components, making the formulation intuitively logical rather than arbitrarily complex.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs poly(ethylene oxide) surfactants that are inexpensive, biocompatible, and function effectively at low concentrations. These readily available materials provide stabilization without requiring complex formulation procedures or specialized components.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Measurement precision

If conventional calibration reagents are used, then calibration can be performed quickly, but measurement accuracy deteriorates due to unstable sensor response

Engineering Contradiction:
Improvemagnesium ion measurement accuracyVSAvoidinitial wetup time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

By optimizing the Ca2+:Mg2+ ratio and pH of calibration reagents to match physiological conditions, the patent creates a stable chemical environment that eliminates rapid wetup. This allows the sensor to achieve accurate, stable readings immediately upon contact with calibration solutions, eliminating the need for extended stabilization periods while maintaining high measurement precision.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The poly(ethylene oxide) surfactants act as intermediaries that prevent protein adsorption and membrane destabilization during the calibration process. This intermediary protection allows rapid calibration without compromising measurement accuracy, as the sensor response remains stable from the first measurement.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Stabilizes sensor performance and reduces initial wetup time, ensuring accurate and reproducible magnesium ion measurements over the sensor's lifespan.

Implementation Method 1

incorporating a pH range of 6 to 8 and poly(ethylene oxide) surfactants to stabilize the sensor and improve response kinetics

Methodology Applied
Scientific EffectSurfactant: Surfactant

Implementation Method 2

a method of calibrating a solid-state planar magnesium sensing electrode... potentiometric ion selective electrode that detects ionized magnesium

Methodology Applied
Scientific EffectIon Exchange: Ion Exchange

Data Source

PatentEP4257975B1Method of calibrating potentiometric magnesium ion selective electrode
Publication Date: 2025.12.31 SIEMENS HEALTHCARE DIAGNOSTICS INC
  • EP4257975B1 patent drawingFigure 1
  • EP4257975B1 patent drawingFigure 2
  • EP4257975B1 patent drawingFigure 3

AI summary

Reagents are disclosed for use with potentiometric magnesium ion selective electrodes, along with kits containing same as well as methods of use thereof.