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Multimodal quantum metrology in living systems using nitrogen-vacancy centres in diamond nanocrystals

At a Glance

Section titled “At a Glance”
MetadataDetails
Publication Date2023-08-01
JournalFrontiers in Quantum Science and Technology
AuthorsJack W. Hart, Helena S. Knowles
InstitutionsUniversity of Cambridge
Citations4
AnalysisFull AI Review Included

Technical Documentation & Analysis: Multimodal Quantum Metrology in Living Systems

Section titled “Technical Documentation & Analysis: Multimodal Quantum Metrology in Living Systems”

Executive Summary

Section titled “Executive Summary”

This perspective highlights the critical role of Nitrogen-Vacancy (NV) centers in diamond nanocrystals for multimodal quantum sensing in complex biological environments. 6CCVD, as an expert supplier of high-purity MPCVD diamond, is uniquely positioned to support the foundational material requirements for this advanced research.

  • Core Application: Realizing nanoscale quantum metrology (thermometry, magnetometry, electric field sensing, NMR) in living systems under ambient conditions using NV centers.
  • Material Requirement: Exceptional electronic spin coherence (T2/T2*) and optical addressability, requiring ultra-high purity Single Crystal Diamond (SCD) precursors for optimal NV creation and performance.
  • Multimodal Sensing: NV centers enable simultaneous or fast-succession measurement of multiple parameters (e.g., temperature, rheology, magnetic fields) within a single nanoparticle probe.
  • Key Advantages: NV nanodiamonds offer exceptional photostability (superior to fluorescent dyes), low cytotoxicity, and nanoscale probing volumes (down to 7 zeptolitres).
  • Engineering Challenge: Mitigating heating effects from 532 nm laser and microwave excitation, requiring specialized substrate designs (e.g., waveguides) and pulsed excitation protocols.
  • 6CCVD Value Proposition: Provision of high-coherence SCD and large-area PCD substrates, along with custom metalization services, essential for developing integrated quantum sensing platforms and microwave delivery architectures.

Technical Specifications

Section titled “Technical Specifications”

The following parameters and performance metrics are extracted from the analysis of NV-based quantum sensing in biological systems:

ParameterValueUnitContext
Typical Excitation Wavelength532nmUsed for continuous spin initialization and readout (ODMR).
Nanodiamond Probing Volume10szeptolitresCorresponds to the volume of a 50 nm diameter sphere.
NMR Sensing Volume (Single NV)7zeptolitresCapable of detecting spins in ~1500 oil molecules.
NV Center Charge States UtilizedNV-, NV0, NV+N/AUsed for spin-based, optical, and electric field sensing modalities.
Photobleaching Half-Life (Dyes)100ssecondsNV centers offer exceptional photostability compared to common fluorescent dyes.
Maximum Nanodiamond Rotation Speed5° per secondObserved during translational-rotational tracking on cell membranes.
Required Magnetic Field SensitivitySmall and transientN/ANecessary for detecting signals like single-neuron action potentials.
Temperature Sensing MechanismLattice expansion/contractionN/AAlters the energy separation of the ground state spin levels.

Key Methodologies

Section titled “Key Methodologies”

The research relies on advanced quantum control and optical techniques enabled by the robust properties of NV centers in diamond. Replicating or extending this work requires precise control over the diamond material and experimental setup.

  1. Optically Detected Magnetic Resonance (ODMR): Monitoring the photoluminescence signal change when external microwaves resonantly excite the NV center ground state (ms = 0 to ms = ±1). Used for thermometry and magnetometry.
  2. T1 Relaxation Time Measurement: Measuring the time taken for the polarized NV state to return to thermal equilibrium. Used to detect local electromagnetic noise, reactive oxygen species (ROS), and nitrogen oxide radicals.
  3. Spin Echo Double Resonance (SEDOR): A pulse delivery technique used to isolate and detect the noise effect from specific target spin species (e.g., local nitrogen impurities).
  4. Nanoscale Nuclear Magnetic Resonance (NMR) Spectroscopy: Exploiting the coupling between the electronic NV spin and nearby nuclear spins to achieve chemical shift resolution and structural information.
  5. Charge State Conversion (Voltage Sensing): Utilizing a strong local electrostatic field to change the NV center energy levels relative to the diamond Fermi energy, facilitating voltage-dependent charge state conversion (NV- <—> NV0).
  6. Microrheology (Passive and Active): Tracking the Mean Squared Displacement (MSD) of nanodiamonds in cells (passive) or probing particle response to a driven force induced by optical trapping (active).
  7. Pulsed Excitation Protocols: Using pulsed microwave and optical illumination to reduce photothermal load and increase sensitivity, particularly critical for in vivo applications.

6CCVD Solutions & Capabilities

Section titled “6CCVD Solutions & Capabilities”

6CCVD provides the high-quality MPCVD diamond materials and custom engineering services necessary to advance multimodal quantum metrology research. Our capabilities directly address the material purity, dimensional control, and integration requirements outlined in this research.

Applicable Materials for Quantum Sensing

Section titled “Applicable Materials for Quantum Sensing”
Research Requirement6CCVD Material SolutionTechnical Justification
High Coherence NV CentersOptical Grade Single Crystal Diamond (SCD)Ultra-low nitrogen and defect density ensures maximum spin coherence (T2/T2*), critical for high-sensitivity NMR and SEDOR experiments. Available in thicknesses from 0.1”m to 500”m.
Integrated Substrates/WaveguidesHigh-Purity Polycrystalline Diamond (PCD)Provides large-area substrates (up to 125mm) with excellent thermal conductivity, crucial for dissipating heat generated by 532 nm laser and microwave excitation in integrated sensing platforms.
Electric Field/Voltage SensingBoron-Doped Diamond (BDD)Controlled doping allows for tuning the Fermi level, which is essential for optimizing the NV charge state conversion (NV- <—> NV0) used in electric field sensing modalities.

Customization Potential for Integrated Systems

Section titled “Customization Potential for Integrated Systems”

The development of advanced quantum biosensors requires precise material integration, including microwave delivery structures and specialized surface treatments. 6CCVD offers comprehensive customization services:

  • Custom Metalization Services: The paper mentions the need for evaporated waveguide structures (e.g., gold/metal lines) onto cell substrates for targeted, lower-power microwave delivery. 6CCVD offers in-house metalization using Au, Pt, Pd, Ti, W, and Cu to create custom microwave architectures directly on SCD or PCD wafers.
  • Precision Polishing: For optimal optical coupling and minimal surface noise, 6CCVD guarantees ultra-smooth surfaces: Ra < 1nm for SCD and Ra < 5nm for inch-size PCD. This is vital for minimizing background fluorescence fluctuations and ensuring stable optical trapping.
  • Custom Dimensions and Thickness: Whether researchers require thin SCD membranes (0.1”m) for high-resolution imaging or thick PCD substrates (up to 10mm) for robust device integration, 6CCVD provides custom dimensions and thicknesses up to 125mm (PCD).

Engineering Support

Section titled “Engineering Support”

6CCVD’s in-house PhD team specializes in MPCVD growth parameters and defect engineering. We can assist researchers with:

  • Material Selection: Consulting on the optimal diamond grade (SCD vs. PCD) and thickness required to balance spin coherence, thermal management, and optical transparency for specific Multimodal Quantum Metrology projects.
  • NV Center Optimization: Advising on precursor material specifications (e.g., nitrogen concentration control) to maximize the yield and quality of NV centers, whether for bulk ensembles or single-NV nanodiamond precursors.
  • Global Logistics: We ensure reliable, global shipping (DDU default, DDP available) of sensitive diamond materials, supporting international research collaborations.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

Nitrogen-vacancy centres in diamond nanocrystals are among the leading candidates for realising nanoscale quantum sensing under ambient conditions. Due to their exceptional electronic spin coherence at room temperature and optical addressability, these solid state spin-based sensors can achieve a wide selection of sensing modalities, including probing temperature, external magnetic and electric field, as well as the detection of nearby electronic and nuclear spins. In this article, we discuss recent progress made utilizing nanodiamond quantum sensors in living systems and explore both opportunities for future advances and challenges that lie ahead.

Tech Support

Section titled “Tech Support”

Original Source

Section titled “Original Source”

References

Section titled “References”
  1. 2010 - Temperature dependence of the nitrogen-vacancy magnetic resonance in diamond [Crossref]
  2. 2017 - Nanoscale nuclear magnetic resonance with chemical resolution [Crossref]
  3. 2014 - A critique of methods for temperature imaging in single cells [Crossref]
  4. 2020 - Sensitivity optimization for nv-diamond magnetometry [Crossref]
  5. 2016 - Optical magnetic detection of single-neuron action potentials using quantum defects in diamond [Crossref]
  6. 2020 - Silicon carbide color centers for quantum applications [Crossref]
  7. 2020 - Nanodiamonds with powerful ability for drug delivery and biomedical applications: Recent updates on in vivo study and patents [Crossref]
  8. 2020 - Optical thermometry with quantum emitters in hexagonal boron nitride [Crossref]
  9. 2020 - Probing and manipulating embryogenesis via nanoscale thermometry and temperature control [Crossref]
  10. 2018 - Mitochondria are physiologically maintained at close to 50 c [Crossref]

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