Porous Insulating Sample Support for DESI Imaging Ionization

Solution Overview

Problem

Desorption electrospray ionization methods face challenges in achieving high signal intensity in mass spectrometry due to inadequate ionization of sample components.

Innovation Solution

A sample support with an electrically insulating substrate and an irregular porous structure, allowing for effective diffusion and retention of samples, combined with a method of irradiating with charged microdroplets to enhance ionization and maintain positional information for high-resolution imaging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a conductive substrate is used to improve sample transfer efficiency, then sample transfer is enhanced, but electrical discharge occurs during microdroplet irradiation

Engineering Contradiction:

Improvesample transfer efficiencyVSAvoidelectrical discharge

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The substrate surface is divided into two regions with different electrical properties: a conductive region for efficient sample transfer and an insulating region (or insulating coating) for preventing electrical discharge during microdroplet irradiation. This local differentiation of electrical properties resolves the contradiction between transfer efficiency and discharge prevention.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

An insulating coating is introduced as an intermediary layer between the conductive substrate and the sample/microdroplet interaction zone. This coating prevents direct electrical contact while allowing the underlying conductive substrate to maintain its sample transfer efficiency, thus mediating between the conflicting requirements.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Quantity of substance

If sample amount on the surface is increased to improve signal intensity, then ionization signal strengthens, but sample diffusion control becomes difficult

Engineering Contradiction:

Improvesample amount on surfaceVSAvoidsample diffusion control

Core Design Contradiction:

Quantity of substanceVSManufacturing precision

Solution Approach 1:

A porous structure is formed on the substrate surface to provide controlled sample diffusion pathways. The porous structure allows the sample to be retained within its pores, preventing uncontrolled diffusion while maintaining an adequate amount of sample on the surface for strong ionization signals. The pore size and distribution can be tuned to control diffusion rates.

Inventive Principle:

Principle #31Porous materials

3Productivity

If microdroplet irradiation distance is reduced to improve ionization efficiency, then ionization efficiency increases, but electrical discharge risk increases

Engineering Contradiction:

Improveionization efficiencyVSAvoidelectrical discharge risk

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The substrate surface is divided into two regions with different electrical properties: a conductive region for efficient sample transfer and an insulating region (or insulating coating) for preventing electrical discharge during microdroplet irradiation. This local differentiation of electrical properties resolves the contradiction between transfer efficiency and discharge prevention.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

An insulating coating is introduced as an intermediary layer between the conductive substrate and the sample/microdroplet interaction zone. This coating prevents direct electrical contact while allowing the underlying conductive substrate to maintain its sample transfer efficiency, thus mediating between the conflicting requirements.

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

The solution enables suitable ionization of sample components, improving signal intensity in mass spectrometry and allowing for high-resolution imaging of two-dimensional molecular distributions.

Implementation Method 1

desorption electrospray ionization is a method in which charged microdroplets are irradiated onto a sample to desorb and ionize the sample

Methodology Applied

Scientific EffectDesorption electrospray ionization: Ionisation

Implementation Method 2

the sample transferred to the first surface can be appropriately diffused into the porous structure, and the amount of the sample remaining on the first surface can be appropriately adjusted

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 3

since the first surface of the substrate of the sample support is an electrically insulating member, even if the microdroplet irradiation unit to which a high voltage is applied is brought close to the first surface, for example, the occurrence of discharge between the microdroplet irradiation unit and the sample support is suppressed

Methodology Applied

Scientific EffectElectrical insulation: Electrical Resistance

Data Source

PatentUS20230290625A1Sample support, ionization method, and mass spectrometry method

Publication Date: 2023.09.14 HAMAMATSU PHOTONICS KK

AI summary

A sample support is a sample support for ionizing a sample. The sample support includes a substrate that includes a first surface having electrical insulating property, a second surface opposite to the first surface, and an irregular porous structure that opens to at least the first surface.