The QT Nuova quantum‑sensing detection platform is a quantum‑level, high spatiotemporal‑resolution free‑radical detection system launched by QT SENSE. Centered on nanoscale magnetic resonance imaging and equipped with NV‑center quantum sensing technology, it enables real‑time, nondestructive detection of free radicals at the single‑cell and subcellular levels, filling a critical technical gap in conventional methods for precisely monitoring free‑radical dynamics at the subcellular scale. By integrating an advanced confocal microscope with quantum‑sensing capabilities, the platform delivers precise measurements of multiple common free radicals, including superoxide, hydroxyl, 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 precise detection of intracellular free radicals, employing 70-nm fluorescent nanodiamonds (FNDs) as its primary sensing载体. Through surface‑modification techniques, it enables targeted imaging of specific subcellular compartments, such as mitochondria, the nucleus, and lysosomes, and is compatible with a wide range of sample types, including live cells, tissue sections, blood samples, and cell supernatants. The system also supports high‑throughput 96‑well plate assays, significantly enhancing research efficiency. Paired with Quantum Pulse software, the platform establishes a fully automated workflow—“sample positioning, FND identification, T1 relaxation measurements, data analysis, and visualized output”—streamlining the application of quantum‑sensing technologies and making complex redox‑biology studies more accessible and broadly applicable. To date, the platform has undergone experimental validation across multiple disciplines, including cardiovascular science, immunology, dermatology, reproductive health, and oncology, establishing itself as a key tool in the fields of free‑radical detection and oxidative‑stress research.

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, it converts the weak magnetic signals generated by free radicals into quantifiable optical signals, enabling precise detection and quantitative analysis of free radicals. Throughout the entire process, no physical contact with the sample is required, ensuring non‑destructive measurement of living cells and preserving their natural physiological state.

The platform’s sensing core consists of fluorescent nanodiamonds (FNDs) doped with nitrogen–vacancy (NV) centers. An NV center is a point defect in the diamond lattice, formed when a nitrogen atom substitutes for a carbon atom and creates a neighboring vacancy; the unpaired electron associated with this vacancy exhibits unique spin‑1/2 quantum properties and is highly sensitive to fluctuations in the local magnetic environment, enabling it to function as a miniature quantum sensor embedded within cells. The detection workflow comprises four key steps: first, FNDs functionalized with appropriate surface ligands are introduced into the sample, where they are delivered to target subcellular compartments—such as mitochondria—via endocytosis or active targeting. Next, the platform irradiates the NV centers with a 532‑nm green laser pulse, exciting the electrons to a higher energy state. Upon cessation of the laser, a dark‑time phase ensues, during which the electrons interact with their surrounding magnetic environment and undergo longitudinal relaxation. Free radicals, possessing unpaired electrons that generate magnetic moments, increase the intensity of ambient magnetic noise as their concentration rises, thereby accelerating the relaxation of the NV‑center electrons and hastening the decay of the fluorescence signal. Finally, a high‑sensitivity avalanche photodiode (APD) detector captures the fluorescence signals at various dark‑time intervals; the acquired data are fitted to an exponential decay model to determine the longitudinal relaxation time (T1) of the NV centers. Notably, T1 exhibits a strong negative correlation with free‑radical concentration, allowing precise quantification of free‑radical levels through quantitative analysis of the T1 decay curve.

In addition, the platform’s integrated confocal microscopy system enables two- and three-dimensional visualization, and when combined with ODMR+T1 mapping, it can generate subcellular‑level maps of free radical distribution, allowing simultaneous detection and imaging. This provides comprehensive data support for investigating 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 platform demonstrates significant advantages in detection accuracy, spatiotemporal resolution, detection modes, and practicality. Leveraging the core attributes of quantum‑sensing technology, it has developed a suite of product features tailored to real‑world research needs, enabling comprehensive compatibility with diverse scenarios and types of free‑radical studies and measurements. Moreover, all performance parameters have been rigorously validated through experimental testing.

In terms of detection performance, the platform achieves nanomolar‑level sensitivity, enabling precise quantification of free radicals in the 1–10 nM range—far below the detection limits of conventional fluorescent probes (on the order of μM) and spectrophotometric methods (also around μM). This capability allows for capturing the dynamic fluctuations of low‑concentration free radicals within cells, meeting the demands of research requiring 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 single organelle level and clearly distinguishing differences in free radical production among cytoplasm, mitochondria, nucleus, and other compartments, thereby fully addressing the limitations of traditional techniques that cannot achieve precise subcellular localization. Compared with conventional methods, this platform employs a nondestructive detection approach: it requires no chemical modification, fixation, or staining of samples, nor does it necessitate the application of external microwave fields. Consequently, it preserves the cell’s native physiological architecture and metabolic state, enabling long‑term, continuous monitoring of the same live cell for up to 75 hours—whereas traditional fluorescent probes are prone to photobleaching, and chemical modifications can disrupt cellular processes, precluding sustained dynamic measurements.

From the perspectives of product design and practicality, the platform’s core sensing carrier, FNDs, is a biocompatible, inert material with stable chemical properties and no cytotoxicity. It can readily penetrate cell membranes to enter living cells without triggering cellular stress responses. Moreover, FNDs exhibit resistance to photobleaching, ensuring signal stability over prolonged measurements—addressing the key limitations of conventional probes, which are prone to degradation and photobleaching. The platform features a fully automated workflow, supported by the Quantum Pulse software, which integrates automatic FND detection, automated T1 relaxation experiments, precise 3D platform control, and one-click data visualization. Users require no advanced expertise in quantum sensing; after basic training, they can operate the system proficiently, significantly lowering the barrier to adopting 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 culture supernatants, and 96-well plate‑based samples. 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 well suited for free radical studies but can also be extended to meet analytical needs in materials science, environmental science, and other related fields.

At the data‑value level, the platform can deliver spatially resolved, quantitative, and dynamic free‑radical detection data, enabling a four‑dimensional analytical framework that integrates qualitative assessment, quantitative measurement, precise localization, and real‑time tracking. Compared with conventional methods that typically provide only qualitative or semi‑quantitative insights, this approach offers more comprehensive and accurate data support for studying oxidative stress mechanisms, validating drug targets, and dissecting disease pathogenesis, thereby helping researchers elucidate, at the molecular scale, the relationships between free radicals, cellular functions, and disease development.

Application Areas and Use Cases

The QT Nuova quantum‑sensing detection platform, with its core attributes of high sensitivity, subcellular resolution, and real‑time, nondestructive measurement, has been successfully deployed across multiple specialized areas of the life sciences. It also demonstrates strong application potential in drug discovery, basic clinical research, and other fields, offering a groundbreaking technological approach to studies of oxidative stress and free radicals. Below are the key application domains along with representative case studies that have been experimentally validated:

(1) Cardiovascular Research

This study focuses on the mechanisms underlying oxidative stress and ischemia–reperfusion injury in cardiomyocytes, using H9‑C2 myoblasts derived from embryonic rat hearts as a model system to mimic 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 of cardiomyocytes decreased by 50% compared with normoxic conditions, indicating a marked increase in mitochondrial free radical levels. During the subsequent 3‑hour reoxygenation phase, mitochondrial T1 relaxation time gradually recovered to approximately 180% of its baseline value, clearly illustrating the dynamic patterns of free radical kinetics during hypoxia–reoxygenation. By identifying mitochondrial free radical kinetics as a central biomarker of oxidative stress, this research provides a precise quantitative assay for evaluating the efficacy of cardioprotective therapies and offers critical data to elucidate the pathophysiological mechanisms of redox imbalance in cardiovascular diseases.

(II) Immunological Research

In a study investigating drug‑induced cellular stress responses and toxicity, mouse macrophages (J774A.1) were used as a model to assess changes in cellular free radicals following treatment with acetaminophen (APAP). The results showed that, after 3 hours of APAP exposure, mitochondrial free radical levels in the macrophages increased by 80% compared with the control group, whereas cytosolic free radical alterations became significant only after 18 hours. Moreover, the T1 values exhibited clear dose‑ and time‑dependence. In parallel experiments assessing oxidative stress induced by CCCP, the platform detected a 50% increase in cellular free radical production following CCCP treatment; subsequent addition of the SOD–CAT antioxidant cocktail resulted in a further 50% reduction, enabling precise differentiation between free radical generation in the cytoplasm and in the mitochondria. This research provides critical subcellular‑level data for evaluating drug‑induced cytotoxicity and elucidating the mechanisms underlying immune cell stress responses, thereby addressing the limitations of conventional assays that cannot accurately resolve 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 to monitor the dynamic changes in free radicals following UVB irradiation. The results showed that after 20 minutes of UVB exposure, the mitochondrial T1 relaxation 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 key molecular nodes and temporal dynamics of UV‑induced mitochondrial stress in skin cells, providing a precise analytical basis for investigating the mechanisms of cutaneous photodamage, evaluating the efficacy of sunscreen products, and developing anti‑photoaging therapeutics. This approach has been adopted in numerous dermatology‑related research projects.

(4) Reproductive Research

In a study focusing on granulosa cells and female fertility, primary human cumulus cells (cGCs) and mural granulosa cells (mGCs) were used as model systems to assess changes in reactive oxygen species (ROS) following treatment with various inducers. The results showed that, after treatment with menadione, ROS levels in both the cytoplasm and mitochondria of granulosa cells increased by 100% compared to the control group. Following exposure to follicle-stimulating hormone (FSH) at 600 mIU/mL, cytoplasmic ROS rose by 40%, while mitochondrial ROS increased by 60%. This study achieved real-time, subcellular‑level measurement of intracellular ROS dynamics in human granulosa cells, offering a novel perspective for investigating the pathogenic mechanisms of female infertility and for evaluating the effects of hormones and pharmacological agents in in vitro fertilization. The findings have been incorporated into basic research projects related to assisted reproductive technologies.

(5) Oncology and Drug Development

In studies investigating the mechanisms of action and efficacy of anticancer drugs, the human breast cancer MDA‑MB‑231 cell line was used as a model to evaluate the effects of ACD1, a candidate drug in clinical trials. Real-time monitoring data revealed that, following 1 hour of exposure to ACD1, mitochondrial T1 values decreased significantly; by 3 hours, the decline in T1 values had further intensified. Moreover, as the duration of treatment increased, the deviation of T1 values from the control group progressively widened, confirming that the drug‑induced sustained oxidative stress response constitutes one of the key mechanisms underlying its inhibition of tumor cell proliferation. This study provides direct mitochondrial stress–related measurement data for validating drug mechanisms and assessing therapeutic efficacy, thereby addressing the limitation of conventional omics approaches, which cannot 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 piroxicam’s inhibitory effects on free radicals in the synovial fluid of osteoarthritis patients, as well as the regulatory roles of ethanol and L‑ascorbic acid on free radicals in mouse liver tissue—demonstrating its cross-disciplinary potential. Looking ahead, with further technological refinement, the platform could be extended to free-radical–related research in additional fields, including neurodegenerative diseases, infectious diseases, and environmental toxicology.