Flash Lamp Triplet DNP for Hyperpolarized Aqueous Solutions
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Solution Overview
Problem
Conventional Dynamic Nuclear Polarization (DNP) techniques are limited in hyperpolarizing a wide variety of compositions, especially those that are soluble and harmless to humans, and require large and expensive laser generating apparatuses.
Innovation Solution
A method and apparatus for nuclear spin hyperpolarization using a benzoic acid derivative doped with a pentacene derivative, allowing for the generation of an aqueous solution with hyperpolarized nuclear spins at room temperature, involving light and microwave irradiation, and subsequent dissolving and resolidification steps to transfer polarization, utilizing a smaller and less expensive apparatus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional DNP technique using thermal equilibration is used, then nuclear spin polarization can be enhanced, but the polarization cannot exceed 660 times the room temperature limit and requires high magnetic field and cryogenic temperature
Solution Approach 1:
The invention changes the fundamental parameter of polarization enhancement from thermal equilibrium-based (limited to 660x) to triplet state-based (unlimited enhancement). By using photoexcited triplet electrons as polarizing agents instead of thermal DNP, the system achieves nuclear spin polarization of several dozen percent at room temperature, eliminating the need for cryogenic temperatures and high magnetic fields.
Solution Approach 2:
The invention replaces the mechanical/thermal system (cryogenic cooling and high magnetic fields) with an optical/quantum system (photoexcitation and triplet state utilization). This substitution allows room temperature operation and eliminates the need for expensive cryogenic equipment and high-field superconducting magnets.
2Measurement precision
If triplet DNP using photoexcited triplet electrons is used, then nuclear spin polarization can be enhanced 660 times or higher than thermal limit, but only solid and hardly soluble substances can be highly polarized
Solution Approach 1:
The invention changes the physical state parameter from solid to soluble solid/liquid by using water-soluble benzoic acid derivatives as the host matrix. This allows triplet DNP to be applied to a wide range of compositions including sugars, amino acids, and pharmaceuticals that are naturally soluble in water, dramatically expanding applicability while maintaining high polarization.
3Measurement precision
If conventional triplet DNP with monochromatic laser is used, then high polarization can be achieved, but a large and expensive laser generating apparatus is indispensable
Solution Approach 1:
The invention replaces expensive, complex monochromatic laser systems with inexpensive, simple flash lamps. The flash lamp provides sufficient photoexcitation energy for triplet DNP without requiring the sophisticated and costly laser generating apparatus, dramatically reducing equipment cost and complexity while maintaining polarization enhancement capability.
4Measurement precision
If high magnetic field of 3T or higher and cryogenic temperature close to 1K are applied, then nuclear spin polarization of a few to several dozen percent can be attained, but a large and expensive apparatus is required
Solution Approach 1:
The invention replaces the mechanical/thermal system (cryogenic cooling and high magnetic fields) with an optical/quantum system (photoexcitation and triplet state utilization). This substitution allows room temperature operation and eliminates the need for expensive cryogenic equipment and high-field superconducting magnets, achieving the same polarization enhancement with simple, inexpensive apparatus.
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 ultrasensitive chemical analysis and metabolic imaging by achieving high nuclear spin polarization of various substances, including those previously inaccessible, using a compact and cost-effective setup.
Implementation Method 1
Photoexcitation of π conjugate molecules of pentacene, for example, leads to electron spin excitation
Implementation Method 2
part of which makes a transition to the photoexcited triplet state by intersystem crossing
Implementation Method 3
triplet DNP using electron spins of molecules in a photoexcited triplet state as polarizing agents
Implementation Method 4
nuclear spin polarization can be enhanced 660 times or higher than the thermal limit of polarization at room temperature
Implementation Method 5
a nuclear spin transferring step of transferring polarization of hydrogen nuclear spins of the substance other than the pentacene derivative in the sample to nuclear spins of the isotope by cross-polarization
Implementation Method 6
the aqueous solution is resolidified, thereby transferring nuclear spin polarization
Data Source
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AI summary
The nuclear spin hyperpolarization method includes the steps of: irradiating a sample, prepared by doping solid benzoic acid derivative with a pentacene derivative, placed in a space where a static magnetic field is formed by a main magnetic field forming unit, with a laser beam from a laser source; following the light irradiation, irradiating the sample with a microwave from a microwave source while applying a sweeping magnetic field; and after repeating the application of sweeping magnetic field, light irradiation and microwave irradiation, dissolving the benzoic acid derivative in the sample. This enables generation of an aqueous solution containing benzoic acid derivative of which nuclear spins are hyperpolarized.