High‐Yield Assembly of Plasmon‐Coupled Nanodiamonds Using DNA Origami for Tuned Emission
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2025-09-27 |
| Journal | Small Structures |
| Authors | Niklas Hansen, Jakub Čopák, Marek Kindermann, David Roesel, Federica Scollo |
| Institutions | Czech Academy of Sciences, J. Heyrovský Institute of Physical Chemistry, Charles University |
| Citations | 2 |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Plasmon-Coupled Nanodiamonds
Section titled “Technical Documentation & Analysis: Plasmon-Coupled Nanodiamonds”Executive Summary
Section titled “Executive Summary”This research demonstrates a robust, high-yield method for precisely positioning Nitrogen-Vacancy (NV) centers in nanodiamonds (NDs) relative to plasmonic gold nanoparticles (AuNPs) using DNA origami. This breakthrough is critical for advancing quantum photonics and nanoscale sensing applications.
- High-Yield Nanoscale Assembly: Achieved assembly yields exceeding 50% for nanodiamond-gold nanoparticle hybrids using a scalable DNA origami platform (12-helix bundle).
- Precise Spatial Control: Demonstrated distance-dependent modulation of NV center photoluminescence (PL) by controlling the interparticle spacing between the FND and AuNP from 140 nm down to 35 nm.
- Plasmonic Enhancement: Observed significant reduction in NV center average lifetime (from 27.0 ns down to 15.0 ns) due to efficient plasmonic coupling.
- Purcell Factor Achievement: Quantified a maximum Purcell factor (FP) enhancement of 1.8 at the closest coupling distance (35 nm).
- Quantum Decay Tuning: Confirmed selective enhancement of the fastest decay component (T3), which is highly beneficial for accelerating spin-state readout rates required in quantum sensing technologies.
- Robust Functionalization: Utilized a covalent DNA functionalization strategy (SPAAC) on polymer-coated FNDs, ensuring high colloidal stability and dense DNA loading (198 ± 6 oligonucleotides per FND).
Technical Specifications
Section titled “Technical Specifications”The following hard data points were extracted from the analysis of the plasmon-coupled NV center assemblies:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Nanodiamond Diameter (davg) | 40 | nm | Fluorescent Nanodiamonds (FNDs) used |
| Gold Nanoparticle (AuNP) Sizes | 20, 40 | nm | Used for plasmonic coupling |
| Interparticle Spacing (Center-to-Center) | 35, 70, 140 | nm | Controlled by DNA origami design |
| Bare NV Center Average Lifetime (τavg) | 27.0 ± 0.5 | ns | DNA-coated NDs reference |
| Closest Coupled NV Center Average Lifetime (τavg) | 15.0 ± 0.1 | ns | 40 nm AuNP, 35 nm spacing |
| Maximum Purcell Factor (FP) | 1.8 | Dimensionless | Achieved at 35 nm spacing (τbare/τsample) |
| Assembly Yield (Maximum) | > 50 | % | Extended binding site configuration |
| DNA Origami Length | ≈ 200 | nm | 12-helix bundle structure |
| DNA Loading Density (FND) | 198 ± 6 | Oligonucleotides | Per FND particle (dense array) |
| FND Fabrication Temperature (Annealing) | 900 | °C | Post-irradiation annealing for NV creation |
Key Methodologies
Section titled “Key Methodologies”The experimental success relied on a sophisticated, multi-step chemical and physical process to prepare and assemble the hybrid structures:
- FND Preparation and Oxidation: Nanodiamonds (MSY 0-0.05) were oxidized (air at 540 °C, followed by acid treatment) and then irradiated with an electron beam (6.6 MeV) and annealed at 900 °C to generate NV centers.
- Silication and Polymer Coating: FNDs were coated with an ultrathin silica layer, followed by the growth of a biocompatible polymer layer (HPMA/AzMA copolymer) via a “grafting through” approach to introduce azide functional groups.
- Covalent DNA Functionalization: DBCO-modified DNA strands were covalently attached to the azide-functionalized FNDs using Strain-Promoted Azide-Alkyne Cycloaddition (SPAAC), ensuring robust binding and high colloidal stability.
- DNA Origami Synthesis: A rod-shaped 12-helix bundle (12HB) DNA origami structure was synthesized via scaffold and staple annealing, designed with specific single-stranded DNA overhangs for NP binding sites.
- Hybrid Nanoparticle Assembly: FNDs were first attached to the origami, followed by the addition of freshly functionalized AuNPs (20 nm or 40 nm) in a 1:1 molar ratio, controlling the interparticle distance via binding site placement.
- Purification and Characterization: Assembled structures were purified using agarose gel electrophoresis and analyzed using correlated Atomic Force Microscopy (AFM) and Fluorescence Lifetime Imaging (FLIM) to measure distance-dependent PL modulation.
6CCVD Solutions & Capabilities
Section titled “6CCVD Solutions & Capabilities”This research highlights the immense potential of NV centers in diamond for quantum applications, particularly when coupled with plasmonic structures. 6CCVD is uniquely positioned to supply the foundational diamond materials and advanced processing required to transition this DNA-origami research into scalable, solid-state devices.
Applicable Materials for Replication and Extension
Section titled “Applicable Materials for Replication and Extension”The paper utilized Fluorescent Nanodiamonds (FNDs), which are Polycrystalline Diamond (PCD) particles. To replicate or, more importantly, extend this research toward commercial quantum devices, 6CCVD recommends the following materials:
| 6CCVD Material | Recommendation | Rationale for Quantum Applications |
|---|---|---|
| Optical Grade Single Crystal Diamond (SCD) | Primary Recommendation | SCD offers superior crystal purity and lattice quality, maximizing NV center coherence times (T2). This is essential for high-fidelity quantum sensing and computing, overcoming the inherent heterogeneity limitations of FNDs noted in the paper. |
| High-Purity Polycrystalline Diamond (PCD) | Alternative/Substrate | Available in large formats (up to 125 mm wafers). Ideal for use as a robust substrate for subsequent lithographic patterning of plasmonic structures or for high-volume FND precursor material. |
| Boron-Doped Diamond (BDD) | Electrochemical Applications | While not directly used for NV centers, BDD substrates are available for integrating plasmonic structures with electrochemical sensing platforms, extending the application scope. |
Customization Potential for Solid-State Integration
Section titled “Customization Potential for Solid-State Integration”The DNA origami method provides nanoscale precision but is limited in scalability. The next logical step is integrating NV centers into lithographically defined plasmonic circuits. 6CCVD offers the necessary material engineering capabilities:
- Custom Dimensions: We supply high-quality SCD and PCD plates and wafers in custom sizes, up to 125 mm diameter (PCD), providing the necessary foundation for large-scale lithography.
- Precise Thickness Control: SCD layers are available from 0.1 µm to 500 µm, allowing researchers to precisely control the depth of NV implantation or the thickness of the diamond layer used for surface functionalization.
- Advanced Metalization Services: 6CCVD provides in-house deposition of plasmonically active metals (Au, Pt, Pd, Ti, W, Cu). This capability allows researchers to define custom plasmonic nanoantennas or nanogrooves directly on the diamond surface, replacing the complex AuNP assembly process and ensuring sub-nanometer precision in NV-plasmon coupling geometry.
- Ultra-Low Roughness Polishing: Achieving efficient plasmonic coupling requires extremely smooth surfaces. Our polishing services guarantee surface roughness of Ra < 1 nm for SCD and Ra < 5 nm for inch-size PCD, optimizing the interface for lithographic patterning and minimizing scattering losses.
Engineering Support
Section titled “Engineering Support”6CCVD’s in-house PhD team specializes in MPCVD growth and NV center engineering. We can assist researchers in optimizing material selection and processing parameters for similar Quantum Photonic and Nanoscale Sensing projects, specifically focusing on:
- NV Center Creation: Consulting on optimal diamond purity and post-growth processing (e.g., irradiation and annealing recipes) to maximize NV yield and quality within SCD substrates.
- Surface Functionalization: Advising on surface termination strategies (e.g., oxygen or hydrogen termination) compatible with subsequent chemical functionalization or lithographic patterning for plasmonic integration.
- Custom Substrate Design: Designing diamond substrates with specific geometries or metal stacks tailored to maximize the Purcell enhancement and directional emission required for high-performance quantum devices.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
Controlling the spatial arrangement of optically active elements is crucial for the advancement of engineered photonic systems. Color centers in nanodiamonds (NDs) offer unique advantages for quantum sensing and information processing; however, their integration into complex optical architectures is limited by challenges in precise and reproducible positioning, as well as efficient coupling. DNA origami provides an elegant solution, as demonstrated by recent studies that showcase the nanoscale positioning of fluorescent NDs and plasmonic gold nanoparticles (NPs). A scalable and robust method is presented for covalently functionalizing NDs with DNA, enabling a high‐yield and spatially controlled assembly of diamond and gold NPs onto DNA origami. By precisely controlling the interparticle spacing, this approach reveals the distance‐dependent modulation of a nitrogen‐vacancy (NV) center photoluminescence (PL). These findings indicate selective plasmon‐driven effects. This work overcomes key limitations in current nanodiamond assembly strategies and provides insights into engineering NV PL by plasmonic coupling. These advancements bring closer to quantum photonic and sensing applications.