ABSTRACT
Coronavirus disease or COVID-19 is a virus from the Coronaviridae family that has caused pandemics throughout the world since the end of 2019. The virus spreads ten times faster through human interaction than SARS-CoV. The RNA sequence of COVID-19 has a 79.5% similarity with SARS-CoV. Fast and specific detection of COVID-19 is needed so that patient detection can be done quickly and accurately. One method that can be developed as a COVID-19 biosensor is aptamers-based biosensors. The aptamer is an artificial oligo nucleic acid that can specifically bind to target molecules. The aptamer is easily and chemically modifiable for increasing stability and reducing toxicity. It shows a comparable affinity for the target virus and better thermal stability than monoclonal antibodies. This advantage makes aptamer a promising candidate in diagnostic and detection applications. The goal of this research is to use an RNA aptamer as the specific recognition element in a portable surface plasmon resonance (SPR) biosensor for the detection of COVID-19 in humans. An aptamer RNA 1 COVID-19 was designed using the COVID-19 sequence from GISAID using the in silico method. End of 3’ aptamer RNA 1 was modified with dithiol. And Then, the aptamer was immobilized on the gold nanoparticle sensor surface via Cysteine-dithiol binding. The RNA solution, that had been extracted from swab samples, was diluted ten times before being used as a sample. The immobilized aptamer RNA 1 captured COVID-19 in RNA solution, causing an increase in refraction index (r.u). An aptamer RNA 1 was found to bind RNA virus of COVID-19 where the positive sample of COVID-19 has refraction index (r.u) between 3 r.u – 10 r.u for various Ct values.
ABSTRACT
Pandemics such as COVID-19 have highlighted the importance of point-of-care sensors for testing, tracing, and treatment to minimize and manage infection. Biosensors have been widely deployed in portable devices such as glucose sensors and pregnancy tests. Their development for point-of-exposure virus detection or point-of-care devices is anticipated but their reliability for the accurate detection of viruses is critical. Nanomaterials, such as metal nanoparticles (NPs), magnetic NPs, quantum dots, carbon-based nanomaterials, and molecularly imprinted polymer (MIP) NPs, have been utilized in biosensors to enhance sensitivity. Molecular imprinting is a cost-effective method to synthesize polymers for selective binding, which have excellent properties as biosensors. More research on MIP NPs can be expected in the near future. The utilization of nanomaterials in several types of transducers for biosensor devices is also illustrated to give an overview of their use. Finally, a summary is given together with a future perspective on how biosensors can be further developed as reliable, portable viral biosensors.
ABSTRACT
Detection of SASR-CoV-2 plays a significant role in reducing the transmission of COVID-19. Antigen swab test is widely used for screening due to its low processing time and cost, while RT-PCR is used in patient monitoring since it is quite expensive. Although the antigen swab test is more affordable than the RT-PCR, it only generates a discrete result: positive or negative. Thus, it cannot be used for patient monitoring. A method using antigen-antibody binding and surface plasmon resonance (SPR) principle was developed in this research to create an affordable, instant, and quantified SARS-CoV-2 detection method. In this study, modified scFv is tested as a potential bioreceptor since it is easier to be expressed than the whole antibody. The results show that the scFv with the best potential was harvested from the periplasm of E. coli and purified. It has a maximum response at 8.02 RU, LOD at 8.34 ng/mL, linearity at 1.38 in the range of 25-200 ng/mL, and a determination coefficient at 92 percent.
ABSTRACT
The rapid spread of COVID-19 disturbs the availability of the diagnostic tests for detecting COVID-19. Recently, a new test method is being developed by the cooperation between BPPT, ITB, Unpad and PT. TMC. The method is called as the Surface Plasmon Resonance (SPR). However, the data output of the SPR device must be further processed to obtain a powerful information. Hence, we propose a new approach for interactively visualizing SPR data by designing a web app platform. By this platform, user/operator can directly upload the SPR data output file in the web app. In the current design, the imported data are stored in the cloud storage. Moreover, user can also enter additional data for the purpose of labelling the graph that will be automatically generated. Bokeh was chosen as a Python library for visualizing data into an interactive graph. The graph features are label, tooltips, and interactive legend. A SPR data can have various signal responses. But, the labels can be as the help to distinguish those responses. The tooltips allow the user to obtain detailed information from a data point. Meanwhile, the interactive legend is used to distinguish SPR data plot and baseline plot. Therefore, by the use of this web app, the SPR sample analysis could be done just within in minutes. It also only requires a web browser and Python to works.