Eco-Friendly Diagnostic Test Offers Rapid and Low-Cost Detection of SARS-CoV-2 Variants


The devastating impact of the COVID-19 pandemic continues to be felt worldwide, particularly in low-income countries and communities with limited access to vaccines. In the battle against this relentless virus, the development of affordable and rapid testing technologies for accurate detection of SARS-CoV-2 variants is crucial for outbreak prevention and infectious disease control. Today, we present a new potential solution, leveraging eco-friendly materials and innovative techniques to create a diagnostic test for COVID-19.

Eco-Friendly Materials for Sustainable Testing:
We have successfully produced cellulose fibers naturally generated by the bacterium Gluconacetobacter hansenii. These biodegradable cellulose fibers serve as an environmentally friendly substrate, offering an alternative for the production of diagnostic tests for COVID-19. Using this sustainable technology, our research team has introduced a novel and label-free potentiometric diagnostic test capable of detecting SARS-CoV-2 within an impressive 10 minutes, at a cost of just US$3.50 per unit.

The Innovative Design:

At the core of this diagnostic test lies the use of bacterial cellulose as a substrate, combined with a carbon-based electrode modified with graphene oxide and the human angiotensin-converting enzyme-2 (ACE2) as its receptor. This combination enables the accurate and precise detection of many emerging SARS-CoV-2 variants, demonstrating exceptional sensitivity, specificity, and accuracy in the analysis of 65 clinical nasopharyngeal/oropharyngeal samples.

In vitro experiments revealed the antimicrobial activity of both modern and archaic protein fragments identified using our machine learning approach. We further evaluated the lead peptides to understand their mechanism of action, resistance to proteolysis, and efficacy as anti-infective agents in two pre-clinical mouse models. Encouragingly, some of these peptides exhibited stability, non-toxicity, and antimicrobial properties.

Affordable and Accessible Testing:

One of the most remarkable aspects of this eco-friendly diagnostic test is its affordability. Priced at just US$3.50 per unit, this low-cost solution has the potential to facilitate widespread testing efforts, particularly in resource-constrained regions. By providing an affordable and accessible option, this innovation could contribute to the early detection and containment of COVID-19 outbreaks, particularly in communities with limited healthcare infrastructure.

The Importance of Eco-Friendly Materials:

Biodegradability and the use of environmentally friendly materials are critical factors in the development of diagnostic tests. The widespread usage of testing materials for pathogens like SARS-CoV-2 and various clinical biomarkers necessitates the exploration of recyclable or biodegradable alternatives to reduce environmental impact. Traditional substrates used for manufacturing electrical circuits and electrodes, such as printed circuit boards (PCBs), contain a significant amount of metals, with nearly 28% metal content, making recycling challenging.

PCBs also consist of nonmetal components, including thermoset resins and reinforcing materials, which further complicate the recycling process due to their network structure and the presence of inorganic fillers. Incineration is not a viable solution for nonmetals, and their disposal in landfills can result in wastage of valuable resources and secondary contamination. Other polymeric substrates commonly used in sensing applications, such as poly(ethylene terephthalate) (PET), polyurethane (PU), polylactide (PLA), polypropylene (PP), and polyethylene (PE), exhibit limited biodegradation in natural environments, contributing to the growing problem of environmental pollution.

Bacterial Cellulose as a Sustainable Substrate:

In this study, we have explored the use of bacterial cellulose (BC) as a substrate for electrochemical devices. BC is a biodegradable extracellular polymer synthesized by bacteria, known for its mechanical resistance, porosity, crystallinity, flexibility, and biocompatibility. BC is already utilized in various industries, including wound care, skin regenerative medicine, and point-of-care (POC) devices, due to its low cost, non-toxic nature, and advantageous properties over commercial paper.

Conclusion: A Green Solution

The introduction of this eco-friendly diagnostic prototype test marks a significant milestone in the fight against COVID-19 and future pandemics. By harnessing the power of sustainable materials and cutting-edge technology, our team has developed a prototype that may pave the way for more sustainable medical solutions in the ongoing battle against COVID-19 and other emerging infectious diseases.

The research findings have been published in Cell Reports Physical Sciences and are now available online:

For more information, please contact:
Machine Biology Group
University of Pennsylvania

Machine Biology Group

August 16, 2023

About Machine Biology Group:
The mission statement of the Machine Biology Group at the University of Pennsylvania is to use the power of machines to accelerate discoveries in biology and medicine.

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