Portable Sensing Devices for Detection of COVID-19: A Review
COVID-19 pandemic has significantly affected the world and changed peoples' lives. It has become a challenge to control its fast transmission and manage the inevitable health problems caused by the disease. Challenges have also been caused by lock-down, quarantine, social distancing, restriction in travel, etc., that have a detrimental impact on the economy, education, employment and even societal and mental health. The lack of easy accessibility of rapid diagnostic technologies makes it difficult to control the outbreak of the pandemic. Advance technology is needed to possibly provide enough time for adapting the desirable treatment procedure and curb the high spread rate of the disease.
The currently used methodology for detecting COVID-19 is Reverse Transcriptase Polymerase Chain Reaction (RT-PCR), which targets the viral genome in the nasal and nasopharyngeal samples. Although it is considered the key standard in sensing the virus, a rapid, cheap, and readily available system is still needed to determine the infection during the incubation period. The other diagnostic methods like CT imaging, nucleic acid tests, gene sequencing, and serological assays are time-taking, expensive, and lack ease of use in a point-of-care (POC) condition. Their false-negative results necessitate a combinatory detection technique, which increases complexity and cost.
With the constraints of the available and conventional approaches and the need for a portable, real-time, and ultra-sensitive alternative for early detection and monitoring of the infection, the research focus shifted to the evolving biosensor technology.
The crown-shaped particle (COVID-19 Virus) is an enveloped, single-stranded RNA virus that encodes spike (S), membrane (M), envelope (E), and nucleocapsid (N) proteins. The surface S protein is considered one of the main biomarkers of the virus since it facilitates the virus’s entry to the host cells. The integral E protein, responsible for the viral life cycles, seems to be the most antigenic target for biosensing. Also, the produced antibodies in the patients’ biological fluids against the virus can be one other alternative target. Researchers can find innovative ways to design accurate systems for detecting SARS-CoV-2-related biomarkers using the advantages offered by the novel tailor-made biosensors.
Similarly, the viral genome is another potential indicator of the virus’s presence. Precise biosensing systems can be designed for spotting the SARS-CoV-2 by employing specific biorecognition elements (BREs) like antibodies, antigens, proteins, whole viruses, nucleic acids, and aptamers. There are several classifications of biosensors capable of detecting tiny amounts of the target using low sample volumes. These portable devices have the required adaptability for being redesigned to recognize not only COVID-19 but also other disease-specific biomarkers and even future pandemic-causing pathogens. Furthermore, their portability, scalability, and simple fabrication process enables mass production, making it available worldwide. It facilitates home diagnostics and allows remote detection without the need for skilled laboratory personnel and expensive equipment.
Different techniques such as electrochemical, optical, surface plasmon resonance (SPR-based), and field-effect transistor (FET-based) biosensors hold massive potential for being used as self-sufficient devices to identify COVID-19 in asymptomatic cases beyond laboratory settings.