Quantum metrology provides a route to overcome practical limits in sensing devices. It holds particular relevance to biology, where sensitivity and resolution constraints restrict applications both in fundamental biophysics and in medicine. Here, we review quantum metrology from this biological context, focusing on optical techniques due to their particular relevance for biological imaging, sensing, and stimulation. Our understanding of quantum mechanics has already enabled important applications in biology, including positron emission tomography (PET) with entangled photons, magnetic resonance imaging (MRI) using nuclear magnetic resonance, and bio-magnetic imaging with superconducting quantum interference devices (SQUIDs). In quantum metrology an even greater range of applications arise from the ability to not just understand, but to engineer, coherence and correlations at the quantum level. In the past few years, quite dramatic progress has been seen in applying these ideas into biological systems. Capabilities that have been demonstrated include enhanced sensitivity and resolution, immunity to imaging artifacts and technical noise, and characterization of the biological response to light at the single-photon level. New quantum measurement techniques offer even greater promise, raising the prospect for improved multi-photon microscopy and magnetic imaging, among many other possible applications. Realization of this potential will require cross-disciplinary input from researchers in both biology and quantum physics. In this review we seek to communicate the developments of quantum metrology in a way that is accessible to biologists and biophysicists, while providing sufficient detail to allow the interested reader to obtain a solid understanding of the field. We further seek to introduce quantum physicists to some of the central challenges of optical measurements in biological science.
Quantum metrology provides a route to overcome practical limits in sensing devices. It holds particular relevance to biology, where sensitivity and resolution constraints restrict applications both in fundamental biophysics and in medicine. Here, we review quantum metrology from this biological context, focusing on optical techniques due to their particular relevance for biological imaging, sensing, and stimulation. Our understanding of quantum mechanics has already enabled important applications in biology, including positron emission tomography (PET) with entangled photons, magnetic resonance imaging (MRI) using nuclear magnetic resonance, and bio-magnetic imaging with superconducting quantum interference devices (SQUIDs). In quantum metrology an even greater range of applications arise from the ability to not just understand, but to engineer, coherence and correlations at the quantum level. In the past few years, quite dramatic progress has been seen in applying these ideas into biological systems. Capabilities that have been demonstrated include enhanced sensitivity and resolution, immunity to imaging artifacts and technical noise, and characterization of the biological response to light at the single-photon level. New quantum measurement techniques offer even greater promise, raising the prospect for improved multi-photon microscopy and magnetic imaging, among many other possible applications. Realization of this potential will require cross-disciplinary input from researchers in both biology and quantum physics. In this review we seek to communicate the developments of quantum metrology in a way that is accessible to biologists and biophysicists, while providing sufficient detail to allow the interested reader to obtain a solid understanding of the field. We further seek to introduce quantum physicists to some of the central challenges of optical measurements in biological science.
Application of quantum imaging in biology In biology, one of the main challenges is achieving a balance between high precision and minimal invasiveness in measurements. With cutting-edge techniques, the primary limitations to experimental accuracy often stem not from device-related noise but from fundamental physical constraints. Since nature is the underlying source of these constraints, it makes sense to go to quantum mechanics, the most basic theory of matter, for a solution. Improved measurement performance may be possible through the application of quantum effects, particularly those pertaining to coherence. It offers useful tools that, at the very least, offer interesting technical solutions even when they don't fully display cohesive behaviors. One of the primary applications of quantum technologies is quantum metrology, which uses the non-classical state of light to measure physical properties with great resolution and sensitivity. For biological applications, the quantum state of light may be utilized for precision enhancement and quantum noise reduction. This explains how quantum metrology, and particularly quantum imaging, can be used to enhance picture quality, measure shifts in quantum scales in biological systems, and boost imaging precision and resolution using quantum light sources, devices, and protocols. In this study, we give a summary of the possible uses of quantum technology in biology and medicine. This review presents a comprehensive overview of how quantum technologies can be applied in biology and medicine. It also explores the latest developments in quantum biological imaging, quantum microscopy, and quantum materials, while discussing the challenges and opportunities these emerging technologies bring.
Quantum-enhanced metrology techniques offer ultra-precise timekeeping, allowing for breakthroughs in navigation systems, global positioning, medical and Biological imaging. Quantum metrology, a core application of quantum technologies, leverages non-classical states of light (such as entanglement and squeezing) to enhance measurement precision, sensitivity, and resolution beyond the classical limits, particularly the shot-noise limit. Its application to bio imaging and microscopy offers significant advantages for studying delicate biological specimens, which are often susceptible to damage from the intense light typically required by conventional high-resolution methods. The abstract highlights the potential of quantum properties of light to revolutionize bio imaging by providing a non-invasive, highly sensitive, and high-resolution platform for observing biological processes at fundamental scales.
Quantum imaging is emerging as a transformative approach for biomedical applications, applying nonclassical properties of light, such as entanglement, squeezing, and quantum correlations, to overcome fundamental limits of conventional techniques. These methods promise superior spatial resolution, enhanced signal-to-noise ratios, improved phase sensitivity, and reduced radiation dose, for potentially safer and more precise imaging for delicate biological samples. Here, we present an overview of quantum optical biomedical imaging technologies as well as quantum-inspired imaging methods, including quantum optical coherence tomography, quantum optical microscopy, ghost imaging, multi-parameter quantum imaging, and imaging with quantum-grade cameras. We describe the operating principles, biomedical applications, and unique advantages of each approach, along with the specific challenges for their translation into real-life practice. This review aims to guide future research toward advancing quantum imaging from experimental demonstrations to impactful biomedical tools.
Much of our progress in understanding microscale biology has been powered by advances in microscopy. For instance, super-resolution microscopes allow the observation of biological structures at near-atomic-scale resolution, while multi-photon microscopes allow imaging deep into tissue. However, biological structures and dynamics still often remain out of reach of existing microscopes, with further advances in signal-to-noise, resolution and speed needed to access them. In many cases, the performance of microscopes is now limited by quantum effects – such as noise due to the quantisation of light into photons or, for multi-photon microscopes, the low cross-section of multi-photon scattering. These limitations can be overcome by exploiting features of quantum mechanics such as entanglement. Quantum effects can also provide new ways to enhance the performance of microscopes, such as new super-resolution techniques and new techniques to image at difficult to reach wavelengths. This review provides an overview of these various ways in which quantum techniques can improve microscopy, including recent experimental progress. It seeks to provide a realistic picture of what is possible, and what the constraints and opportunities are.
Quantum biology (QB) is frequently recognized as an emerging field, applying quantum theory to study life sciences in combination with physics, mechanics, mathematics, statistics, and modern biology, promising novel insights into biological phenomena. Besides QB, there has been a rise in focus on quantum technology tools, particularly their biological applications. Using quantum light sources, quantum devices, and quantum protocols can help improve the accuracy and resolution of measurement, spectroscopy, and sensing. This approach could lead to a better quality of sensing and measuring changes at quantum scales in biological systems. Certain quantum phenomena, including quantum correlation, quantum entanglement, quantum interference, quantum coherence, and quantum squeezing, can be used in quantum metrology to create new sensing and spectroscopic techniques. For the first time, in this article, the role of quantum spectroscopy and sensing in medical and biological applications is reviewed. Additionally, the opportunities and problems of state-of-the-art quantum biological sensing approaches are outlined.
Over the past few decades, medical imaging has revolutionized the way clinicians diagnose, monitor, and treat diseases. However, despite significant advancements in imaging resolution, contrast, and computational reconstruction, several challenges remain unresolved — especially in terms of early-stage detection, noise reduction, and functional imaging at the cellular or molecular level. In recent years, quantum physics has emerged as a disruptive force with the potential to drastically enhance medical imaging technologies through the application of its fundamental principles such as quantum superposition, entanglement, tunneling, and spin dynamics. This research explores the intersection of quantum mechanics and medical imaging engineering, with a primary focus on how quantum phenomena are being utilized to elevate the performance and capability of key imaging modalities like Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), and optical-based quantum imaging. The study presents an in-depth analysis of how quantum concepts are applied in practice — such as the role of spin alignment and magnetic resonance in MRI, the use of entangled photon pairs in PET scanning, and the integration of quantum dots in high-contrast optical imaging. Beyond existing technologies, the paper investigates cutting-edge developments including quantum-enhanced sensors, quantum computing for real-time image reconstruction, and the promise of quantum artificial intelligence in image interpretation. By analyzing both theoretical frameworks and experimental findings, the study highlights the significant advantages that quantum technologies bring — such as improved spatial resolution, higher signal-to-noise ratio, and reduced patient exposure to radiation. Despite its promise, the integration of quantum physics into medical imaging is not without challenges. The research discusses limitations such as system decoherence, scalability, clinical costs, and the gap between laboratory research and clinical deployment. In conclusion, this paper argues that while still emerging, the application of quantum physics holds transformative potential for the future of diagnostic imaging, and could ultimately lead to more accurate, efficient, and personalized healthcare.