https://www.mdpi.com/2079-6374/9/2/65/pdf

An Alternative Medical Diagnosis Method: Biosensors for Virus Detection.

Recent development of fiber-optic chemical sensors and biosensors: Mechanisms, materials, micro/nano-fabrications and applications

Recent advances of electrochemical and optical enzyme-free glucose sensors operating at physiological conditions.

In the last decades, fiber Bragg gratings (FBGs) have become increasingly attractive to medical applications due to their unique properties such as small size, biocompatibility, immunity to electromagnetic interferences, high sensitivity and multiplexing capability. FBGs have been employed in the development of surgical tools, assistive devices, wearables, and biosensors, showing great potentialities for medical uses. This paper reviews the FBG-based measuring systems, their principle of work, and their applications in medicine and healthcare. Particular attention is given to sensing solutions for biomechanics, minimally invasive surgery, physiological monitoring, and medical biosensing. Strengths, weaknesses, open challenges, and future trends are also discussed to highlight how FBGs can meet the demands of next-generation medical devices and healthcare system.

/pdf/fiber-bragg-gratings-for-medical-applications-and-future-4zkfznppij.pdf

Fiber Bragg Gratings for Medical Applications and Future Challenges: A Review

Surface plasmon resonance has established itself as an immensely acclaimed and influential optical sensing tool with quintessential applications in life sciences, environmental monitoring, clinical diagnostics, pharmaceutical developments and ensuring food safety. The implementation of sensing principle of surface plasmon resonance employing an optical fiber as a substrate has concomitantly resulted in the evolution of fiber optic surface plasmon resonance as an exceptionally lucrative scaffold for chemical and biosensing applications. This perspective article outlines the contemporary studies on fiber optic sensors founded on the sensing architecture of propagating as well as localized surface plasmon resonance. An in-depth review of the prevalent analytical and surface chemical tactics involved in configuring the sensing layer over an optical fiber for the detection of various chemical and biological entities is presented. The involvement of nanomaterials as a strategic approach to enhance the sensor sensitivity is furnished concurrently providing an insight into the diverse geometrical blueprints for designing fiber optic sensing probes. Representative examples from the literature are discussed to appreciate the latest advancements in this potentially valuable research avenue. The article concludes by identifying some of the key challenges and exploring the opportunities for expanding the scope and impact of surface plasmon resonance based fiber optic sensors.

[INVITED] Recent advances in surface plasmon resonance based fiber optic chemical and biosensors utilizing bulk and nanostructures

Cancer biomarker sensing using packaged plasmonic optical fiber gratings: Towards in vivo diagnosis.

The detection of circulating tumor cells (CTCs), which are responsible for metastasis in several forms of cancer, represents an important goal in oncological diagnosis and treatment. These cells remain extremely challenging to detect, despite numerous previous studies, due to their low concentration (1-10 cells/mL of blood). In this work, an all-fiber plasmonic aptasensor featuring multiple narrowband resonances in the near-infrared wavelength range was developed to detect metastatic breast cancer cells. To this aim, specific aptamers against mammaglobin-A were selected and immobilized as receptors on the sensor surface. In vitro assays confirm that the label-free and real-time detection of cancer cells [limit of detection (LOD) of 49 cells/mL] occurs within 5 min, while the additional use of functionalized gold nanoparticles allows a 2-fold amplification of the biosensor response. Differential measurements on selected optical resonances were used to process the sensor response, and results were confirmed by microscopy. The detection of only 10 cancer cells/mL was achieved with relevant specificity against control cells and with quick response time.

/pdf/rapid-detection-of-circulating-breast-cancer-cells-using-a-1lid2c5oit.pdf

Rapid Detection of Circulating Breast Cancer Cells Using a Multiresonant Optical Fiber Aptasensor with Plasmonic Amplification.

HER2 breast cancer biomarker detection using a sandwich optical fiber assay

Plasmonic immunosensors are usually made of a noble metal (in the form of a film or nanoparticles) on which bioreceptors are grafted to sense analytes based on the antibody/antigen or other affinity mechanism. Optical fiber configurations are a miniaturized counterpart to the bulky Kretschmann prism and allow easy light injection and remote operation. To excite a surface plasmon (SP), the core-guided light is locally outcoupled. Unclad optical fibers were the first configurations reported to this end. Among the different architectures able to bring light in contact with the surrounding medium, a great quantity of research is today being conducted on metal-coated fiber gratings photo-imprinted in the fiber core, as they provide modal features that enable SP generation at any wavelength, especially in the telecommunication window. They are perfectly suited for use with cost-effective high-resolution interrogators, allowing both a high sensitivity and a low limit of detection to be reached in immunosensing. This paper will review recent progress made in this field with different kinds of gratings: uniform, tilted and eccentric short-period gratings as well as long-period fiber gratings. Practical cases will be reported, showing that such sensors can be used in very small volumes of analytes and even possibly applied to in vivo diagnosis.

https://www.mdpi.com/1424-8220/17/12/2732/pdf

Plasmonic Optical Fiber-Grating Immunosensing: A Review.

Cortisol is a stress biomarker whose chronic elevated levels are associated with higher risk of metabolic syndromes, anxiety, and cardiovascular diseases, among other medical conditions. A new immunosensor based on plasmonic tilted fiber Bragg grating (TFBG) has been developed and tested for rapid and ultrasensitive cortisol detection. The gold coated TFBG was characterized to surrounding refractive index (SRI) changes and functionalized with anti-cortisol antibodies via cysteamine. The functionalization was monitored, allowing to verify the SRI alteration at the fiber surface by the respective molecular adhesion. In this work, an alternative method to the monitoring of the most sensitive surface plasmon resonance mode was explored, based on tracking the local maximum of the plasmonic signature of the lower envelope of the spectra. With this interrogation method, the sensor achieved a sensitivity to cortisol detection of 0.275 ± 0.028 nm/ng.mL−1, for the detection range of 0.1-10 ng/mL, with a total wavelength shift of around 3 nm, which is higher several orders of magnitude than the usually reported TFBG plasmonic immunosensors. The proposed biosensor provides a rapid, highly sensitive, label-free, low-volume consumption method for cortisol detection, with a working range suitable to monitor different biological samples.

/pdf/cortisol-in-fiber-ultrasensitive-plasmonic-immunosensing-33rjdczlcn.pdf

Médéric Loyez

Papers

Cancer biomarker sensing using packaged plasmonic optical fiber gratings: Towards in vivo diagnosis.

Rapid Detection of Circulating Breast Cancer Cells Using a Multiresonant Optical Fiber Aptasensor with Plasmonic Amplification.

HER2 breast cancer biomarker detection using a sandwich optical fiber assay

Plasmonic Optical Fiber-Grating Immunosensing: A Review.

Cortisol In-Fiber Ultrasensitive Plasmonic Immunosensing