SARS-CoV-2 Detection Using Optical Fiber Based Sensor Method

Abstract

The SARS-CoV-2 Coronavirus disease, also known as the COVID-19 pandemic, has engendered the biggest challenge to human life for the last two years. With a rapid increase in the spread of the Omicron variant across the world, and to contain the spread of COVID-19 in general, it is crucial to rapidly identify this viral infection with minimal logistics. To achieve this, a novel plastic optical fiber (POF) U-shaped probe sensing method is presented for accurate detection of SARS-CoV-2, commonly known as the COVID-19 virus, which has the capability to detect new variants such as Omicron. The sample under test can be taken from oropharyngeal or nasopharyngeal via specific POF U-shaped probe with one end that is fed with a laser source while the other end is connected to a photodetector to receive the response and postprocess for decision-making. The study includes detection comparison with two types of POF with diameters of 200 and 500 µm. Results show that detection is better when a smaller-diameter POF is used. It is also seen that the proposed test bed and its envisaged prototype can detect the COVID-19 variants within 15 min of the test. The proposed approach will make the clinical diagnosis faster, cheaper and applicable to patients in remote areas where there are no hospitals or clinical laboratories due to poverty, geographic obstacles, or other factors.

Keywords: COVID-19; COVID-19 detection; PCR; SARS-CoV-2; U-shaped probe; optical fiber sensor.

Figure 1

(a) shows the microscopic image of SARS-CoV-2 while (b) shows the structural diagram of SARS-CoV2. Structural schema of SARS-CoV-2 showing Spikes, envelope, nucleocapsid and M protein. The inset shows the structure of spike.

Figure 2

The infection cycle of SARS-CoV-2 (COVID-19). The life cycle summarizes the steps of how Coronavirus is transmitted and replicated.

Figure 3

Block diagram of latest COVID-19 detection technologies structures: surface plasmon resonance (SPR) configuration (A–D); (E) bioreceptor fiber optic sensing method; (F) surface enhancement Raman scattering, and (G) laser-induced fluorescence (LIF) detector.

Figure 4

Block diagram of U-shaped fiber-optic sensing for SARS-CoV-2 detection general steps that are followed. (A) presents creation of U-shaped fiber; (B) represents functionality activation of U-shaped fiber probe; (C) represents metallic nanoparticles synthesis and immobilization and (D) presents the overall methodology for fiber-optic sensing for SARS-CoV-2 detection.

Figure 5

Schematic diagram of U-shaped optical fiber probe connected on one side with LED laser source and other probe with the photodiode or spectrometer. The performance is then evaluated.

Figure 6

Comparison of two POFs in terms of intensity with diameters 200 and 500 µm are compared with specimen with a COVID-19 positive and negative result.

Figure 7

Comparison of two POFs in terms of intensity with diameter 200 µm, compared with specimen taken from oropharyngeal or/and nasopharyngeal.

Figure 8

Comparison of 200 µm POF with COVID-19 specimen and healthy specimen evaluated in terms of Raman Peaks.

Figure 9

X-ray of (a) normal patient with no COVID-19 symptoms for pelvis surgery with negative PCR test; (b) is a patient with COVID-19 symptoms, positive PCR test on day 1 and 3; (c) is a pneumonia patient with negative PCR test on day 1, 3 and 5.

Figure 10

Comparison of Normal, COVID-19 and Pneumonia patients in terms of intensity with diameters 200 µm POF are compared.

Figure 11

(a) Process flow of the conventional COVID-19 detection followed in the hospital under observation; (b) process flow of the proposed early detection of COVID-19.

Figure 11

(a) Process flow of the conventional COVID-19 detection followed in the hospital under observation; (b) process flow of the proposed early detection of COVID-19.

Figure 12

The proposed prototype will have a following shape. The U-shaped optical fiber probe connected to the laser and photodiode while green light shows a COVID positive, and COVID negative is reported by red light. (a) Shows front view while (b) shows lateral view of the prototype.