DNA origami precisely positions single-photon emitters for quantum technologies

Making a single-photon emitter in a 2D semiconductor is not the hard part. Making one exactly where you want it on a chip — that has been the problem.

Researchers from Nanjing University, Skoltech, and Ludwig Maximilian University of Munich have demonstrated a solution: DNA origami triangles, 127 nanometers along each outer edge, used as programmable molecular scaffolds to position thiol binding sites on monolayer molybdenum disulfide with roughly 90 percent yield and about 13 nanometers of mean placement accuracy. The emitters show single-photon emission confirmed by second-order correlation g(2)(0) values well below the 0.5 threshold, with nanosecond lifetimes and minimal photobleaching or spectral diffusion. The work appears in Light: Science & Applications, published March 9, 2026.

The problem, briefly stated: solid-state single-photon emitters in 2D materials are well-established — demonstrations in MoS2 date to the mid-2010s. But conventional techniques, including strain engineering, ion irradiation, and random defect formation, produce emitters at unpredictable locations. Integrating them into photonic circuits, sensor arrays, or on-chip quantum networks requires knowing precisely where each one sits.

Thiol molecules bind to sulfur vacancies in MoS2, creating exciton trapping sites roughly 50 meV below the free exciton energy — the mechanism that makes the defects optically active. The challenge is that depositing thiols onto a MoS2 surface via standard solution or vapor methods follows Poisson statistics: at typical coverages, these approaches hit a roughly 37 percent binding-efficiency ceiling that fundamentally limits how many targeted sites produce functioning emitters. DNA origami placement (DOP) sidesteps this. Each triangle carries thiol molecules in a defined geometry; the triangle itself is positioned using lithographic markers as a guide. The result is a deterministic address for each emitter — not a statistical bet. The team reports approximately 90 percent placement yield, well above the Poisson floor.

The process matters as much as the outcome. The researchers used a dry-stamp transfer technique to bring DNA-patterned surfaces into contact with chemical-vapor-deposited MoS2 monolayers — a practical choice that avoids the solution-phase complications that have historically complicated DNA origami on semiconductor interfaces. This is described as an explicit design decision in the paper, and it is the detail that makes the result practically interesting for anyone trying to replicate it.

The collaboration spans the groups you would expect in high-quality MoS2 work: Tim Liedl's team at LMU Munich contributed the DNA origami expertise; Alexander Hoegele's group handled optical spectroscopy; Kenji Watanabe and Takashi Taniguchi from Japan's National Institute for Materials Science supplied the bulk crystal material used for chemical vapor deposition growth. First author is Shen Zhao, with Zhijie Li and Irina V. Martynenko among the contributors. The arXiv preprint (2501.12029) was posted in January 2025 and revised in May of that year.

The caveat that sits underneath everything: all measurements were performed at 4 Kelvin. No room-temperature results are shown. This is standard for MoS2 single-photon emitters and is not a criticism — it is the main gap between this result and any near-term practical application. The paper is explicit about this and frames the work as a proof of concept, with wafer-scale integration listed as a future pathway rather than a demonstrated achievement.

This is an engineering advance, not new physics. The combination of deterministic placement with 2D-material quantum emitters is novel; the underlying mechanisms have been shown separately. What the field now has is a reproducible method — one that other groups can build on — for making quantum light sources exactly where they want them. Whether that scales to production wafers is the question worth watching.