Emerging Applications of Optical Bio-Sensors

Abstract

In the simplest words, a bio-sensor is an analytic device. In recent years, bio-sensors have shown emerging contribution in medical diagnosis, drug discovery, and treatment process. In this regards, continuous research is ongoing and many more features are being added in the sensing technologies. Optical sensing technology is no more bound in research area but also in the commercial use for the betterment of mankind. There are different types of bio-sensors particularly optical which have already been developed and research is going to expand many more of them. Sensing applications are not limited in glucose, DNA, cancer cell detection, drug discovery, immunological, Hepatitis B virus, and enzyme detection but also many more development is knocking at the door. Therefore, this review paper is focused on the applications and functions of bio-sensors (especially optical) in medical diagnostics and treatment.

Transducer Technologies for Biosensors and Their Wearable Applications

“…Optical biosensors can be categorized as “label-free”, and “label-based” depending on the targeted binding or simultaneous detection of a range of biomarkers. Commonly reported optical biosensing techniques are based on spectrometry, fiber-optics (FOBs) [ 125 ], interferometry [ 126 ], and surface plasmon resonance (SPR) [ 127 , 128 ]. Moreover, similar to the conventional optical phenomena, absorption, fluorescence [ 129 ], refraction, optical diffraction [ 85 ], phosphorescence, and Raman scattering are highly incorporated in optical biosensing.…”

“…Optical biosensors empower the user over case-specific application areas with the advantages of real-time detection, continuous interaction at a low-cost [ 127 , 128 ], compatibility with small volume samples, remote sensing in out-of-reach areas [ 123 , 124 , 125 ], and fast detection [ 131 , 132 , 133 , 134 ]. For instance, FOBs can be adapted for the detection of a variety of bio-events from the growth of Escherichia coli to the ovary cells of hamsters.…”

“…In addition, the SPR technique makes the identification of molecular binding possible by offering high sensitivity and label-free detection [ 128 ]. SPR imaging is also used in clinical studies for screening biomarkers and therapeutic targets [ 127 ]. On the other hand, evanescent-wave biosensors reflect great detection sensitivities in a short period of time and are capable of disease diagnosis with high accuracy due to their ability to assess kinetics and affinity of interactions by optically monitoring biomolecular interactions concurrently [ 135 , 136 ].…”

Near Infrared LEDs-Based Non-Invasive Blood Sugar Testing for Detecting Blood Sugar Levels on Diabetic Care

“…Measurement of blood sugar by non-invasive techniques is carried out using the light propagation method on the human body, especially in the subcutaneous tissue. Light is fired with various sources, including near-infrared (NIR) spectroscopy, mid-infrared spectroscopy, fluorescence, Raman spectroscopy, and thermal infrared [12] [13] [14].…”