QST's Heat-Etched Nanodiamond Quantum Sensors Cut Particle-to-Particle Variation to a Quarter and Raise the Signal 55 Percent: ACS Nanoscience Au, 7 October 2026
Quentir Medicine Monitor
Evidence-based insights for quantum medicine. Published by Quentir Systems LLC · October 7, 2026.
A diagnostic test is only useful when it gives the same answer for the same sample, whichever batch of reagent the laboratory happens to open that morning. Tiny diamond particles that act as quantum sensors have shown remarkable sensitivity in research settings, yet each particle has behaved slightly differently, and that spread has stood between the laboratory result and a test a hospital could rely on.
On 7 October 2026 Japan's National Institutes for Quantum Science and Technology (QST), with Chiba University, Institute of Science Tokyo, Kyoto University and the Chiba start-up Type-I Technologies, reported a new way to make nanodiamond quantum sensors that behave far more alike. According to the QST press release of 7 October 2026, the new process reduces particle-to-particle variation to about a quarter of that of conventional particles and raises the quantum signal by 55 percent. The groups see the work as groundwork for quantum liquid biopsy, the detection of very small amounts of disease-related molecules in blood, and for batch production of uniform sensors rather than hand-picking a few outstanding particles.
The paper, "Spin-Uniform Nanodiamond Quantum Sensors for Reproducible Intracellular Thermometry," by Chihiro Suzuki, Ryuji Igarashi and nine co-authors, appeared online in ACS Nanoscience Au (DOI 10.1021/acsnanoscienceau.6c00068) on the same day. For a laboratory director, a diagnostics buyer or a clinician following early cancer detection, it addresses the question that comes before any claim of sensitivity: whether two sensors given the same sample report the same value.
How QST and Kyoto University etch diamond with heat to keep only the crystal core
A nanodiamond sensor depends on a defect called the nitrogen-vacancy center, a spot in the diamond lattice where a nitrogen atom sits next to a missing carbon atom. When green laser light falls on the particle, the defect glows red, and microwave measurements of that glow, a method called optically detected magnetic resonance (ODMR), reveal small changes in temperature and in the chemical surroundings. Particles a few tens to a few hundred nanometers across can enter living cells.
The conventional route crushes larger diamond into nanoparticles first and creates the sensing defects afterward. QST explains that mechanical crushing leaves scratches and strain that differ from particle to particle, so every particle carries its own quirks into the measurement. The new process reverses the order. The team first builds nitrogen-vacancy centers into relatively large diamond particles of good crystal quality, then heats them gently in air so that the surface oxidizes away a little at a time. Diamond faces oxidize at different rates, and the researchers tuned the conditions so that disordered outer material goes first. What remains is the most orderly central tenth of the original particle, still small enough for work inside cells.
QST group leader Ryuji Igarashi compared the method to brewing daiginjo sake, in which rice grains are polished down to their core before brewing, as reported by Nikkei on 7 October 2026.
Quantum pillar: sensing. Technology readiness: TRL 4 of 9. In the Monitor's assessment, the improved sensor particles have been made and tested in the laboratory, including temperature readings inside a standard cultured human cancer cell line, but they have not yet been used on patient blood, in a clinical study or in a hospital laboratory.
What the paper measured: a quarter of the D-value spread, 55 percent more ODMR signal and 0.7 °C in HeLa cells
The team reports three results. The first concerns the D value, the reference frequency used to convert a nitrogen-vacancy reading into a temperature. With conventional particles this value differs from one particle to the next even at the same temperature, which makes comparisons between sensors, or between cells, difficult. The new particles show about a quarter of the conventional spread in the D value.
The second result is signal strength. The ODMR signal, one of the measures of sensor sensitivity, rose by 55 percent, so each particle gives a clearer reading as well as a more consistent one.
The third result comes from living cells. In HeLa cells, a widely used human cancer cell line, the new particles gave clearer signals than conventional ones, and the uncertainty of temperature readings between cells fell to about 0.7 °C. QST presents this as evidence that controlling particle variation at the material stage allows stable quantum measurement inside a complex cellular environment. Cell temperature reflects metabolism and drug response, and the groups suggest that, once the relation between cell temperature and disease is better understood, temperature could help distinguish cell states in future tests, including cancer tests.
Intracellular thermometry with nanodiamonds has a long history. Georg Kucsko and colleagues at Harvard demonstrated nanometre-scale thermometry in a living cell in Nature in August 2013, and recent work has pushed resolution much further on single, carefully characterized particles, as the Monitor described in its reading of the 280-nanometer Cambridge, Warwick and Cardiff diamond with a 682 microkelvin resolution floor. The QST result addresses a different problem: making many particles alike enough that results can be compared.
Why uniform sensors matter for quantum liquid biopsy and early cancer diagnosis
The larger aim is blood testing. QST's background section describes quantum liquid biopsy research in which nanodiamond sensors detect disease-related molecules in body fluids, and it states that detection sensitivity at the zeptomole level has been reported. The release also cites the often-quoted figure of about 100,000 times the sensitivity of conventional body-fluid diagnostics. Neither figure is a result of this paper, and both await independent clinical confirmation.
For a test that uses many particles at once, variation between particles becomes variation between results. A hospital laboratory needs a test that gives the same value across production lots and across days. That is why the groups describe the step as moving nanodiamond sensors from technology that measures with high sensitivity to measurement that can be trusted and compared. The work belongs to a Japanese national program: the SIP third-phase project on a quantum diagnostic platform for ultra-early in vitro diagnosis, alongside the BRIDGE program on mass preparation of nano quantum sensors.
What QST and Type-I Technologies plan for mass production by fiscal 2028 and use around 2030
The process improves many particles together instead of selecting outstanding ones one by one, which is what makes batch manufacturing conceivable. Nikkei reports that QST aims to have a mass-production system in place by fiscal 2028 and, around 2030, to bring the sensors into practical use in settings such as health checkups, working with Type-I Technologies and other partners. Type-I's representative director, Kiichi Kaminaga, is a co-author of the paper and also a senior researcher at QST.
Several questions remain open before a clinical buyer could act. The paper reports material uniformity and cell thermometry; it does not report a diagnostic test on patient samples, a clinical accuracy study or a regulatory submission. Lot-to-lot consistency at industrial scale is a stated goal and has not yet been shown. The useful next evidence would be the same uniformity figures measured across several production batches, followed by a liquid biopsy assay run on clinical blood samples with a conventional reference method alongside.
For now, the 7 October paper demonstrates one route toward more uniform nanodiamond sensors. Its value for blood testing still requires validation at the level of a complete assay.
Sources
Primary source: Chihiro Suzuki, Tamami Yanagi, Risa Ujiie, Masanori Fujiwara, Izuru Ohki, Hiroshi Abe, Shinobu Onoda, Takeshi Ohshima, Norikazu Mizuochi, Kiichi Kaminaga and Ryuji Igarashi, Spin-Uniform Nanodiamond Quantum Sensors for Reproducible Intracellular Thermometry, ACS Nanoscience Au, 7 October 2026, with the joint press release of QST, Chiba University, Institute of Science Tokyo, Kyoto University and Type-I Technologies. Also drawn on: Nikkei's report of 7 October 2026, QST's SIP project page, and Kucsko et al., Nature, 2013. Readiness and implications are the Monitor's editorial assessments.