Optical Ion Detection Using Interference Microscopy for High-Mass Ions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current ion detectors for mass and/or ion mobility spectrometers face challenges in detecting high molecular weight ions efficiently, as large ions generate fewer secondary particles upon impact, limiting the upper mass limit for reliable detection to around 50,000 Daltons for singly charged ions.
Innovation Solution
An ion detector utilizing a transparent substrate and an interference microscope to detect ions by scattering and reflecting electromagnetic radiation, allowing for the efficient detection of high molecular weight ions by analyzing the interference patterns caused by ions impacting the surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ions impact a conversion dynode at high velocity to generate secondary electrons, then detection sensitivity is improved, but the upper mass limit for reliable detection is limited to about 50,000 Daltons
Solution Approach 1:
The patent replaces the mechanical impact detection system (conversion dynode) with an optical detection system (interference microscope). Instead of relying on mechanical impact to generate secondary electrons, the invention uses optical interference to detect ions directly when they land on the detector surface, eliminating the mass-dependent secondary electron generation process and enabling detection of high molecular weight ions beyond 50,000 Daltons.
Solution Approach 2:
The invention changes the detection parameter from secondary electron count (which decreases with increasing ion mass) to optical interference signal (which remains detectable across a wide mass range). By transforming the detection mechanism and its underlying physical parameter, the system maintains sensitivity for both low and high molecular weight ions.
2Power
If high acceleration potential is applied to increase ion kinetic energy, then secondary particle generation is enhanced, but large ions still travel slower and generate fewer secondary particles
Solution Approach 1:
The patent eliminates the secondary particle generation process entirely by replacing the electron multiplication mechanism with direct optical detection. The interference microscope detects the physical presence of ions on the surface through light scattering and interference, without requiring any secondary particle generation, thus resolving the limitation where large ions generate fewer secondary particles despite high kinetic energy.
3Device complexity
If a conversion dynode is used for ion detection, then detection mechanism is simple, but reliable detection is limited to ions with molecular weight up to about 50,000 Daltons
Solution Approach 1:
The patent substitutes the conversion dynode mechanism with an interference microscope system. While the optical system is more complex than a simple dynode, it provides universal detection capability across all mass ranges. The interference microscope uses light scattering and optical path difference measurements that are independent of ion mass, thereby achieving both adaptability and reasonable device complexity.
Solution Approach 2:
The interference microscope serves as a universal detector that can detect ions of any mass by measuring their physical presence on the surface through optical interference. This multi-functional approach replaces the mass-limited dynode system with a detector that maintains consistent performance across the entire mass spectrum, from small to very large ions.
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
Enables the detection of high molecular weight ions beyond the conventional mass limit, improving the sensitivity and capability of mass and ion mobility spectrometry by using interference microscopy to detect ions that stick to an optically transparent substrate.
Implementation Method 1
The ion detector may be configured such that electromagnetic radiation from the source is reflected by the substrate.
Implementation Method 2
a detector configured to detect one or more ions by detecting electromagnetic radiation scattered by one or more ions at the surface
Implementation Method 3
The detector may be configured to detect one or more ions by detecting an interference pattern caused by interference of electromagnetic radiation (from the source that is) reflected from the substrate and electromagnetic radiation (from the source that is) scattered by one or more ions at the surface
Data Source
AI summary
An ion detector comprises a surface configured to receive one or more ions and a detector configured to detect one or more ions by detecting electromagnetic radiation scattered by one or more ions at the surface.