The QT Nuova quantum sensing platform is a quantum-level, high spatiotemporal-resolution free-radical detection system launched by QT SENSE. Centered on nanomagnetic resonance imaging technology and integrated with NV-center quantum sensing, the platform enables real-time, non-destructive detection of free radicals at the single-cell and subcellular levels, thereby filling the technical gap in conventional methods for precise monitoring of free-radical dynamics at the subcellular scale. By combining an advanced confocal microscope with quantum-sensing technology, the platform delivers highly accurate detection of multiple common free radicals, including superoxide, hydroxyl radicals, and nitric oxide, with detection sensitivity down to the nanomolar level and spatial resolution better than 300 nanometers. It can capture free-radical dynamics on subsecond timescales, providing a new, high-precision analytical tool for life-science research, drug discovery, and clinical basic research.

The platform’s core design is centered on the need for precise detection of intracellular free radicals in living cells. It employs 70-nm fluorescent nanodiamonds (FNDs) as the primary sensing platform, and through surface-modification techniques enables targeted detection of specific subcellular compartments, including mitochondria, the nucleus, and lysosomes. The platform is compatible with a wide range of sample types, such as live cells, tissue sections, blood samples, and cell supernatants, and supports high-throughput batch analysis on 96-well plates, thereby significantly enhancing research efficiency. Paired with proprietary Quantum Pulse software, the platform establishes a fully automated workflow that encompasses “sample positioning—FND identification—T1 relaxation measurement—data analysis—visual output,” simplifying the application of quantum-sensing technologies and making complex redox biology research more accessible and widely adoptable. To date, the platform has undergone experimental validation across multiple research areas, including cardiovascular science, immunology, dermatology, reproductive health research, and oncology, establishing itself as a core tool for free-radical detection and oxidative-stress studies. It has cumulatively supported the successful implementation of numerous national-level research projects and corporate drug-development initiatives.

Working Principle

The core operating principle of the QT Nuova quantum sensing platform is based on the quantum sensing properties of diamond nitrogen-vacancy (NV) color centers. By integrating magnetic noise detection with T1 relaxation time measurement, the platform converts the weak magnetic signals generated by free radicals into quantifiable optical signals, enabling precise detection and quantitative analysis of free radicals. Importantly, the entire detection process requires no physical contact with the sample and is non-destructive to living cells, thereby preserving their natural physiological state to the greatest extent possible.

The platform’s sensing core consists of fluorescent nanodiamonds (FNDs) doped with nitrogen–vacancy (NV) color centers. An NV center is a point-defect structure in the diamond lattice in which a nitrogen atom substitutes for a carbon atom, creating a vacancy; the unpaired electron associated with this vacancy exhibits unique spin-1/2 quantum properties and is highly sensitive to fluctuations in the surrounding magnetic environment, making it suitable for use as a miniature quantum sensor embedded within cells. The detection workflow comprises four core steps: first, FNDs functionalized with targeting ligands are introduced into the sample system, where they are delivered to the target subcellular compartment—such as mitochondria—via endocytosis or active targeting; next, the platform illuminates the NV centers with a 532-nm green laser pulse, promoting the electrons to an excited state; upon cessation of the laser, a dark-time phase ensues, during which the electrons interact with the local magnetic environment and undergo longitudinal relaxation; free radicals possess unpaired electrons that give rise to magnetic moments; the higher their concentration, the greater the intensity of ambient magnetic noise, which in turn accelerates the relaxation of the NV-center electrons and leads to a faster decay of the fluorescence emission intensity; finally, a high-sensitivity avalanche photodiode (APD) detector captures the fluorescence signals at different dark-time intervals, the acquired data are fitted to an exponential decay model, and the longitudinal relaxation time (T1) of the NV centers is calculated. Notably, T1 is significantly negatively correlated with the concentration of free radicals, so quantitative analysis of the T1 curve enables precise quantification of free-radical concentrations.

In addition, the platform’s integrated confocal microscopy system enables two- and three-dimensional visual imaging; when combined with ODMR+T1 mapping technology, it can generate subcellular-resolution maps of free-radical distribution, thereby achieving simultaneous detection and imaging. This provides comprehensive data support for studying the spatial distribution and dynamic changes of free radicals.

Advantages and Key Features

Compared with conventional free-radical detection methods, the QT Nuova quantum-sensing detection platform demonstrates significant advantages in detection accuracy, spatiotemporal resolution, detection modes, and practicality. Leveraging the core characteristics of quantum-sensing technology, it has developed a suite of product features that closely align with the practical needs of scientific research, enabling comprehensive adaptation to diverse scenarios and types of free-radical research and detection. Moreover, all performance parameters are substantiated by rigorous experimental validation, with no exaggerated claims.

In terms of detection performance, the platform achieves nanomolar-level sensitivity, enabling precise quantification of free radicals in the 1–10 nM range—far surpassing the detection limits of conventional methods such as fluorescent probes (with a lower limit on the order of μM) and spectrophotometry (also with a μM-level lower limit). This capability allows for the capture of dynamic changes in low-concentration intracellular free radicals, thereby meeting the research demands for trace-level free-radical analysis. Moreover, the platform offers subcellular spatial resolution and subsecond temporal resolution, facilitating real-time monitoring of free-radical dynamics at the level of individual organelles. It can clearly distinguish differences in free-radical production among distinct cellular compartments, including the cytoplasm, mitochondria, and nucleus, thus fully filling the gap left by traditional techniques that lack the precision to perform subcellular localization and quantification. Compared with conventional detection methods, this platform employs a non-destructive approach: no chemical modification, fixation, or staining is required, nor is an external microwave field applied. Consequently, the natural physiological structure and metabolic state of the cells remain intact, enabling long-term, continuous monitoring of the same living cell for up to 75 hours. By contrast, conventional fluorescent probes are prone to photobleaching, and chemical modifications can interfere with cellular physiological processes, making long-term dynamic monitoring impossible.

From a product design and practicality standpoint, the platform’s core sensing carrier, FNDs, is a biocompatible, inert material that exhibits chemical stability and no cytotoxicity. It can efficiently traverse cell membranes to enter living cells without triggering cellular stress responses. Moreover, FNDs possess exceptional resistance to photobleaching, ensuring signal stability throughout long-term measurements—thereby addressing the key limitations of conventional probes, which are prone to degradation and photobleaching. The platform also features a fully automated workflow, supported by the Quantum Pulse software suite, which integrates automatic FND identification, automated T1 relaxation experiments, precise 3D platform control, and one-click data visualization. Users require no specialized background in quantum sensing; with basic training, they can operate the system proficiently, significantly lowering the barrier to entry for quantum sensing technologies.

In addition, the platform boasts exceptional sample compatibility and scalability, accommodating a wide range of sample types, including live cells, tissue sections, blood, serum, cell supernatants, and batch samples from 96-well plates. It can also be seamlessly integrated with standard fluorescence microscopes, confocal microscopes, and other research instruments, without requiring any modifications to existing experimental workflows. Furthermore, the platform supports magnetic noise spectroscopy, enabling the detection of various substances such as magnetic nanoparticles, metal ions, and paramagnetic materials. As a result, it is not only suitable for free-radical research but can also be extended to meet analytical needs in materials science, environmental science, and other related fields.

From a data-value perspective, the platform can deliver spatially resolved, quantitative, and dynamic free-radical detection data, thereby establishing a four-dimensional analytical framework that integrates qualitative identification, quantitative measurement, spatial localization, and real-time tracking. Compared with conventional methods that typically provide only qualitative or semi-quantitative assessments, this approach offers more comprehensive and precise data support for research on oxidative stress mechanisms, validation of drug targets, and pathological analysis of diseases, enabling researchers to elucidate, at the molecular level, the relationships between free radicals, cellular functions, and disease pathogenesis.

Application Areas and Use Cases

The QT Nuova quantum sensing and detection platform, with its core features of high sensitivity, subcellular resolution, and real-time, non-destructive measurement, has been successfully applied across multiple specialized areas of the life sciences. It also demonstrates significant application potential in drug discovery, basic clinical research, and other fields, providing cutting-edge technological tools for research on oxidative stress and free radicals in various disciplines. The following are the core application areas and representative case studies that have been experimentally validated:

(1) Cardiovascular Research

This study focuses on the mechanisms of oxidative stress and ischemia-reperfusion injury in cardiomyocytes, using H9-C2 myoblasts derived from embryonic rat hearts as a model system to simulate the hypoxia–reoxygenation conditions encountered in clinical ischemia-reperfusion. Platform-based measurements revealed that when the oxygen concentration in the culture environment was reduced to below 1%, the mitochondrial T1 relaxation time in cardiomyocytes decreased by 50% compared with normoxic conditions, indicating a substantial increase in mitochondrial reactive oxygen species levels. During the subsequent 3-hour reoxygenation phase, the mitochondrial T1 relaxation time gradually recovered to 180% of its normoxic value, clearly demonstrating the dynamic kinetic changes of reactive oxygen species during the hypoxia–reoxygenation process in cardiomyocytes. By identifying mitochondrial reactive oxygen species dynamics as a core biomarker of oxidative stress, this research provides a precise quantitative assay for evaluating the therapeutic efficacy of cardioprotective interventions and offers critical empirical data to advance our understanding of the pathophysiological mechanisms underlying redox imbalance in cardiovascular diseases.

(2) Immunological Research

In a study on drug-induced cellular stress responses and toxicity assessment, mouse macrophages J774A.1 were used as a model to examine changes in cellular free radicals following treatment with acetaminophen (APAP). The results showed that after 3 hours of APAP exposure, the level of free radicals in macrophage mitochondria increased by 80% compared with the control group, whereas changes in cytosolic free radicals became significant only after 18 hours; moreover, the T1 values exhibited clear dose- and time-dependence. In parallel, an oxidative stress assay induced by CCCP revealed that CCCP treatment increased cellular free-radical production by 50%, and this increase was markedly reduced by 50% upon addition of the superoxide dismutase–catalase (SOD–CAT) scavenger, thereby enabling precise differentiation between free-radical generation in the cytoplasm and that in the mitochondria. This study provides core subcellular-level data for assessing drug-induced cytotoxicity and elucidating the mechanisms underlying immune-cell stress responses, filling the gap left by conventional detection techniques that have been unable to accurately distinguish subcellular free-radical distribution.

(3) Dermatological Research

Focusing on the mechanisms of UV-induced skin cell damage and photoaging, this study used human keratinocyte HacaT cells as the experimental model to examine the dynamic changes in free radicals following UVB irradiation. The results showed that after 20 minutes of UVB exposure, the mitochondrial T1 time decreased by 60% compared with the control group, while free radical levels increased significantly and continued to rise with prolonged irradiation. These findings clearly elucidate the critical molecular nodes and dynamic patterns of UV-induced mitochondrial stress in skin cells, providing a precise analytical basis for research on the mechanisms of cutaneous photodamage, evaluation of sunscreen product efficacy, and development of anti-photoaging drugs. This approach has since been adopted in numerous dermatological research projects.

(4) Fertility Research

In a study on granulosa cells related to female fertility, primary human cumulus cells (cGCs) and mural granulosa cells (mGCs) were used as model systems to examine changes in reactive oxygen species following treatment with various inducers. The results showed that, after treatment with menadione, the intracellular and mitochondrial concentrations of reactive oxygen species in granulosa cells increased by 100% compared with the control group; whereas treatment with 600 mIU/mL follicle-stimulating hormone (FSH) led to a 40% increase in cytoplasmic reactive oxygen species and a 60% increase in mitochondrial reactive oxygen species. This study achieved real-time, subcellular-level measurement of intracellular reactive oxygen species dynamics in human granulosa cells, providing a novel research perspective for investigating the pathophysiological mechanisms of female infertility and for evaluating the effects of hormones and pharmacological agents used in in vitro fertilization. The findings have already been applied to basic research projects in assisted reproductive technologies.

(5) Oncology and Drug Development

In studies on the mechanisms of action and efficacy evaluation of anticancer drugs, the human breast cancer MDA-MB-231 cell line was used as a model to assess the activity of ACD1, a candidate drug for clinical trials. Real-time monitoring data from the platform revealed that, 1 hour after exposure to ACD1, mitochondrial T1 values decreased significantly; by 3 hours, the decline in T1 values had further intensified, and with prolonged treatment, the deviation of T1 values from the control group gradually increased. These findings confirm that the sustained oxidative stress response induced by the drug is one of the core mechanisms underlying its inhibition of tumor cell proliferation. This study provides direct mitochondrial stress–related measurement data for validating the mechanisms of action and evaluating the efficacy of anticancer drugs, thereby addressing the limitation of conventional omics technologies, which are unable to directly quantify mitochondrial oxidative stress.

In addition, the platform has been applied in areas such as synovial fluid analysis for arthritis and studies of oxidative stress in liver tissue—for example, assessing the inhibitory effect of piroxicam on free radicals in the synovial fluid of osteoarthritis patients, as well as the regulatory effects of ethanol and L-ascorbic acid on free radicals in mouse liver tissue—demonstrating its cross-disciplinary application potential. Looking ahead, with further technological optimization, the platform can be extended to free-radical–related research in even more fields, including neurodegenerative diseases, infectious diseases, and environmental toxicology.