Cost-Effective Fiber Optic Solutions for Biosensing

Abstract

In the last years, optical fiber sensors have proven to be a reliable and versatile biosensing tool. Optical fiber biosensors (OFBs) are analytical devices that use optical fibers as transducers, with the advantages of being easily coated and biofunctionalized, allowing the monitorization of all functionalization and detection in real-time, as well as being small in size and geometrically flexible, thus allowing device miniaturization and portability for point-of-care (POC) testing. Knowing the potential of such biosensing tools, this paper reviews the reported OFBs which are, at the moment, the most cost-effective. Different fiber configurations are highlighted, namely, end-face reflected, unclad, D- and U-shaped, tips, ball resonators, tapered, light-diffusing, and specialty fibers. Packaging techniques to enhance OFBs’ application in the medical field, namely for implementing in subcutaneous, percutaneous, and endoscopic operations as well as in wearable structures, are presented and discussed. Interrogation approaches of OFBs using smartphones’ hardware are a great way to obtain cost-effective sensing approaches. In this review paper, different architectures of such interrogation methods and their respective applications are presented. Finally, the application of OFBs in monitoring three crucial fields of human life and wellbeing are reported: detection of cancer biomarkers, detection of cardiovascular biomarkers, and environmental monitoring.

Aptamers Targeting Membrane Proteins for Sensor and Diagnostic Applications

“…Biosensors integrating optical fiber technologies have also been well-described in research articles and numerous reviews and have acquired special interest recently [169,170]. These fiber optic biosensors are shown to have numerous advantages that include but are not limited to rapid, ultrasensitive, label-free, real-time, low-volume, and on-site detection, as well as miniaturization.…”

Optoelectronic Pressure Sensor Based on the Bending Loss of Plastic Optical Fibers Embedded in Stretchable Polydimethylsiloxane

“…These adaptable sensors are made of flexible materials and can be manufactured in a variety of shapes and sizes to detect various parameters, such as pressure, through various sensing principles [ 13 , 19 ], such as electrical resistance [ 16 , 20 , 21 ], capacitance [ 20 , 22 ], piezo-electricity [ 23 ], resonance [ 11 ], or fluctuations in light intensity [ 24 , 25 ]. In contrast to rigid electronic devices, which have stricter shape limitations [ 26 ], higher risk of mechanical failure (particularly when subjected to strain or deformation that is incompatible with their rigid structure) [ 27 ], more difficult integration with tissues or organic materials [ 28 ], and higher weight and volume [ 8 , 27 ], flexible electronics can combine a variety of electronic components with flexible material hosts that can withstand a wide range of strains, such as tension, compression, bending, or torsion [ 3 , 17 ], with significant benefits including design flexibility, lightness and thinness, manufacturing versatility, and cost-effectiveness [ 26 , 29 , 30 ]. These sensing devices must also comply with specific requirements, such as being bio-compatible [ 12 , 31 ], safe [ 3 , 12 , 31 ], lightweight, non-toxic [ 3 ], stretchable, flexible [ 3 , 12 ], and hydrophobic [ 8 , 17 ], to ensure that they are tightly integrated and adhered to.…”

“…The amount of light lost is proportional to the sensor’s curvature or bending. This change in light intensity can be measured with a photodetector, which allows the amount of pressure exerted to be calculated [ 30 , 36 ]. Sensors based on this technology have some advantages over rigid electronic sensors, such as electromagnetic immunity, corrosion resistance, electrical isolation, environmental resistance, compactness, being lightweight, and high sensitivity [ 33 , 34 , 35 ], which makes them suitable for industrial, healthcare, and bio-medical research.…”

Numerical model to optimize the design of plasmonic optical fiber tips towards highly sensitive biosensing

“…The first SPR biosensors involved a prism structure and, although they are still commercially available, the bulkiness of the devices makes their use more difficult in several scenarios such as in-situ biosensing [1], [2]. Optical fibers can bypass this issue owing to their small size and flexibility, meaning that they can be employed for both non-invasive and invasive monitoring, while also guaranteeing electrical safety and minimal signal attenuation [3]. As a result, these optical fiber sensors have found application in a number of research fields including medical diagnostics, food security and environmental monitoring, among others [1].…”