A Brief Overview of Medical Fiber Optic Biosensors and Techniques in the Modification for Enhanced Sensing Ability

Abstract

In this paper, we provide a brief overview of fiber optic biosensors for use in MedTech, specifically to aid in the diagnoses and treatment of those with chronic medical conditions. Fiber optic cables as components of biological sensors make them especially effective in biological systems that may require ultra-sensitive detection of low-frequency signals in hard to reach areas. This systematic review focuses on the differentiating factors of fiber-optic biosensors, which are tailored to apply the sensor to specific health needs. The main components of FOBS (fiber optic biosensors) such as biosensing elements, fiber optic cables, optical element enhancements, transducers, sensing strategies, photodetectors, and signal processing are covered in detail by showcasing the recent developments in modifications to these components. This paper pays particular attention to the alterations made in biosensing elements including pH elements, enzymatic elements, as well as those sensors utilizing antibodies and whole-cell bacteria. This paper reviews and discusses several published examples in the research stage of development or to give the reader an overall scope of the field. The need for research on biosensing equipment is increasing, as the number of individuals with chronic diseases and the geriatric population require more effective, accurate, and mobile sensing ability and redcued invasiveness. FOBS offer a sensing solution that is accurate, tailorable to almost any clinical need, has abundant and relatively cheap material requirements, and a well-established technological base in fiber optic technology. This small price tag and large market potential make FOBS a desirable research area.

Label-Free Biosensors for Laboratory-Based Diagnostics of Infections: Current Achievements and New Trends

“…In the latter, live natural or engineered microorganisms (such as Escherichia coli or Staphylococcus aureus), integrated on a sensory substrate, assimilate target organic compounds from biosubstrates (such as, for example, antibodies from blood serum) and simultaneously act as a sensitive mechanism [25,[68][69][70][71][72]. In this case, a positive reaction to the promoter of the target molecule after its transport through the cell membrane and diffusion inside the bacterial cell causes expression of the reporter gene, which is recorded as a quantitative response via optical [7,24,26,39,56] or electrochemical signals [30,[48][49][50]73].…”

“…Catalytic electrochemical label-free biosensors have been used for a long time, but they revealed a number of disadvantages associated with the unstable activity or inhomogeneity of the enzyme, which mediates the need for calibration [48,73]. These shortcomings led to the development of a number of biomolecules with various different electrochemical properties, which led to the rapid evolution of this type of sensors and the emergence of more stable biosensors.…”

“…The need to develop electrochemical sensors has become especially urgent for biological agent indication systems in which early detection or monitoring (for example, environmental safety, biosafety, or monitoring molecular markers of the infection process) is of great importance [71,73,[96][97][98].…”

“…The prospect of electrochemical label-free biosensors is undeniable, since they do not require complex or expensive equipment, can be used in the field, and even be implanted into the human body for continuous monitoring of various biologically active compounds [48,71,73,96].…”

“…To expand the analytical capabilities of electrochemical biosensors, work is underway to improve the methods of immobilization of the biocomponent on the electrode, to miniaturize the sensor elements, and to increase their stability. The main limitation of the use of biosensors in medicine, biomedical research, and environmental protection is associated with the need to use one type of sensor to determine only one compound [50,71,73,96].…”