Nanophotonic sensors are becoming increasingly popular due to their high sensitivity and detection limits. These sensors offer a compact and powerful solution for various applications, ranging from chemical analysis to biosensing for point-of-care diagnostics. With their miniature size and impressive performance, these sensors are poised to lead the next generation of sensing technologies.
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Introduction to Nanophotonics
Nanophotonics focuses on light-matter interactions at the nanoscale. This study holds great scientific significance because the behavior and interaction of matter at the nanoscale vary substantially from that of macroscale structures.
Nanophotonics involves a range of nontrivial physical effects beyond diffraction limits, providing new opportunities for applications in optical switching, light harvesting, luminescence, sensing and media transmitting technologies.
How Do Nanophotonic Sensors Work?
Nanophotonic sensors rely on light-matter interactions to detect physical, chemical, or biological events at nanoscale levels. These sensors have shown great promise in biosensing, overcoming the shortcomings of current bioanalytical tools in terms of cost, simplicity, sensitivity, and miniaturization.
Nanophotonic sensors detect changes in a nanostructure's refractive index or optical absorption. Light interacting with the nanostructure causes a change in the refractive index or optical absorption, which can be measured by monitoring changes in the sensor's resonance wavelength or transmission level.
Infrared-guided-wave nanophotonic sensors rely on evanescent field detection to identify biological analytes. The perturbations caused by these analytes in the medium can be detected by measuring changes in the cladding's optical absorption or refractive index. This enables the determination of the presence and concentration of the target material.
Applications of Nanophotonic Sensors
Nanophotonic sensors have various applications in food safety, healthcare, pharmaceuticals, environmental monitoring, and the forensics industry. Some of these applications are discussed below:
Rapid Detection of Food Quality and Contaminants
The accurate and rapid analysis of food quality and safety is critical for human health and safety. Nanophotonic sensors are becoming increasingly popular for food analysis due to their low cost, fast detection, high sensitivity, and specificity.
These sensors can detect contaminants from various food matrices, making them a versatile tool in the food processing industry. Moreover, they are designed to be user-friendly, enabling non-expert operators to conduct on-site testing quickly and easily.
Nanophotonic Sensors Monitor Processes in Living Cells
Nanophotonic sensors designed using nanoplasmonic materials can be used to monitor cell proliferation. The sensors are coated with silicon dioxide and gold, which act as optical antennae to detect changes in nanoplasmonic resonances caused by cell binding.
These sensors can detect and monitor cell proliferation without chemical labels, preserving cell viability and providing a label-free platform for long-term monitoring.
Evanescent sensing-based nanophotonic biosensors have emerged as viable candidates for environmental monitoring due to their label-free detection capabilities and high sensitivity. In addition, these sensors can detect even trace amounts of pollutants, making them an ideal tool for early warning systems.
Rapid and Reliable Diagnosis of Viral Diseases
Nanophotonic sensors offer a promising solution for rapidly and accurately diagnosing viral diseases.
These sensors can be integrated into compact devices for point-of-care testing with the ability to detect viral biomolecules with high sensitivity and operational robustness. This can greatly improve respiratory virus diagnostics, including COVID-19, and offer a potential solution for managing and controlling pandemics.
Such label-free biosensors provide a cost-effective and scalable approach for testing large populations and tracking the spread of viral diseases.
Real-Time In-Situ Oil Detection
Nanophotonic sensors offer a promising solution for the real-time in-situ monitoring of various fluids, such as oil.
The strong confinement of photons around the nanostructures of the sensors enables intense light-matter interactions between the fluids and photons, allowing for ultra-sensitive detection and monitoring of fluid composition and flow.
Recent Research and Development
Nanophotonic Sensor for Accurate Biochemical Analysis
A study published in Analytical Chemistry designed a compact device using the nanophotonic sensor for biochemical analysis to simplify and improve blood tests.
The researchers applied thin protein films of bovine serum albumin to the sensor chip surface for experimentation. As a result, the sensor was highly adaptable for selective analysis of multicomponent solutions with high sensitivity and could perform accurate blood tests with only a small sample volume.
The research highlighted the potential of nanophotonic sensors for regulating surface change in real-time, which can be used in point-of-care devices. Such devices have promising applications in detecting pathological conditions early and monitoring treatments' effectiveness.
Hybrid Nanophotonic–Microfluidic Sensor for Cancer Detection
A study published in Optics Letters has developed a lab-on-a-chip device for gas and liquid analysis and may have the potential to detect and monitor cancer. The device uses nanophotonic optical sensors and microfluidic channels to detect changes in the spectral characteristics of fluids and gases pumped through it.
The sensor's compact size enables it to effectively analyze samples with extremely low concentrations, making it a valuable tool for detecting and monitoring cancer biomarkers such as exosomes in blood.
Since exosome concentrations are typically low in the early stages of cancer, the sensor's ability to accurately identify and quantify these biomarkers could lead to earlier cancer detection and treatment.
Nanophotonic sensors have shown promising sensitivity for detecting molecular binding events. However, significant research is needed to translate scientific advances into daily life devices.
Advancements in nanoscale optical materials, integrated photonics, and optoelectronics are expected to pave the way for the development of portable and cost-effective nanophotonic sensors, which will cater to the future demands of healthcare, environmental monitoring, and food safety.
References and Further Reading
Aamir Iqbal, M., Ashraf, N., Shahid, W., Awais, M., Khan Durrani, A., Shahzad, K., & Ikram, M. (2022). Nanophotonics: Fundamentals, Challenges, Future Prospects and Applied Applications. Nonlinear Optics - Nonlinear Nanophotonics and Novel Materials for Nonlinear Optics. doi.org/10.5772/intechopen.98601
Bhalla, N., Sathish, S., Sinha, A., & Shen, A. Q. (2018). Large‐Scale Nanophotonic Structures for Long‐Term Monitoring of Cell Proliferation. Advanced Biosystems, 2(4), p. 1700258. https://doi.org/10.1002/adbi.201700258
Chen, H., Zhang, L., Hu, Y., Zhou, C., Lan, W., Fu, H., & She, Y. (2021). Nanomaterials as optical sensors for application in rapid detection of food contaminants, quality and authenticity. Sensors and Actuators B: Chemical, 329, p. 129135. https://doi.org/10.1016/j.snb.2020.129135
Chocarro-Ruiz, B., Fernández-Gavela, A., Herranz, S., & Lechuga, L. M. (2017). Nanophotonic label-free biosensors for environmental monitoring. Current Opinion in Biotechnology, 45, pp. 175-183. https://doi.org/10.1016/j.copbio.2017.03.016
Kuzin, A., Chernyshev, V., Kovalyuk, V., An, P., Golikov, A., Goltsman, G., & Gorin, D. (2022). In Situ Monitoring of Layer-by-Layer Assembly Surface Modification of Nanophotonic-Microfluidic Sensor. Analytical Chemistry, 94(42), pp. 14517-14521. https://doi.org/10.1021/acs.analchem.2c03909
Kuzin, A., Chernyshev, V., Kovalyuk, V., An, P., Golikov, A., Ozhegov, R., ... & Goltsman, G. (2022). Hybrid nanophotonic–microfluidic sensor for highly sensitive liquid and gas analyses. Optics Letters, 47(9), pp. 2358-2361. https://doi.org/10.1364/OL.457309
Nanjunda, S. B., Seshadri, V. N., Krishnan, C., Rath, S., Arunagiri, S., Bao, Q., ... & Srinivasan, B. (2022). Emerging nanophotonic biosensor technologies for virus detection. Nanophotonics. doi.org/10.1515/nanoph-2022-0571
Yahzao Liu. (2018). Oil detection by novel optical means: Nanophotonic Sensors. [Online]. Faculty of Civil Engineering and Geosciences of The Delft University of Technology (TU Delft). Available at: https://www.tudelft.nl/citg/over-faculteit/afdelingen/geoscience-engineering/sections/reservoir-engineering/seminars/oil-detection-by-novel-optical-means-nanophotonic-sensors