Nanotechnology-based disinfectants and sensors for SARS-CoV-2

Nanotechnology-based disinfectants and

sensors for SARS-CoV-2

Nanotechnology-based antimicrobial and antiviral formulations can prevent SARS-CoV-2 viral dissemination, and

highly sensitive biosensors and detection platforms may contribute to the detection and diagnosis of COVID-19.

Sepehr Talebian, Gordon G. Wallace, Avi Schroeder, Francesco Stellacci and João Conde

One thing we have learned so far amid
the current coronavirus disease
2019 (COVID-19) pandemic is the
degree to which we are limited in our fight
against respiratory viral diseases. Up to
now SARS-CoV-2 has spread to over 215
countries, with more than 15,000,000 people
infected, and over 615,000 deaths to date
(Johns Hopkins University Coronavirus
Resource Center, 21 July 2020). Our most
important line of defence is our own
immune system, however people who are
immunocompromized, or people with at
least one underlying co-morbidity (that is,
cardiovascular diseases/hypertension and
diabetes, and other chronic underlying
conditions), are highly vulnerable and their
sole line of defence is sanitizers, face masks,
immune system boosters and drugs that are
clinically approved1. Scientists around the
world have made promising strides
towards developing approaches to
prevent COVID-192. However, there
are still challenges for the development
of therapeutics or vaccines, such as
regulatory issues, large-scale production
and deployment to the public3. It will take
months before we can have a global answer
to this pandemic. Furthermore, we must be
prepared for potential outbreak of a second
and even a third wave of the virus, which
calls for alternative options to reinforce our
arsenal against not only COVID-19 but also

Fig. 1 | Nanotechnology-based viral disinfectants work against SARS-CoV-2 by preventing viral dissemination on air, surfaces and protective equipment.

Nanomaterials can be used to promote surface oxidation by releasing toxic ions and therefore preventing viral dissemination by inhibiting binding/penetration

of viral particles, either by generation of reactive oxygen species and/or photothermal-based reactions such as heat that destroy viral membranes. NPs,

nanoparticles; ROS, reactive oxygen species; UV, ultraviolet.

 

Fig. 2 | Nanotechnology-based sensors for SARS-CoV-2 detection, involved in the development of platforms for viral tagging and nano-diagnostic

assays. Nanomaterials functionalized with nucleic acids or antibodies represent the main lines of nano-based detection, via colorimetric or antigen-binding

assays, as well as light and photothermal platforms. Ab, antibody; FRET, Förster resonance energy transfer; LSPR, localized surface plasmon resonance; NPs,

nanoparticles; PNA, peptide nucleic acid; PPT, photothermal therapy.

 

 

other viral diseases that can potentially

become pandemics. The silver lining

amidst this crisis is the state of our

technological advances mainly in the field

of nanotechnology. So far, a significant

body of work has covered the development

of nano-based vaccines or anti-viral agents

to block SARS-CoV-2, all of which are

currently far from public implementation

due to lengthy and strict regulatory affairs4.

Consequently, we propose that

nanotechnology could have a closer impact

on the current pandemic when implemented

in two defined areas: (1) Viral disinfectants,

by developing highly effective nano-based

antimicrobial and antiviral formulations

that are not only suitable for disinfecting

air and surfaces, but are also effective in

reinforcing personal protective equipment

such as facial respirators. (2) Viral detection,

by developing highly sensitive and accurate

nano-based sensors that allow early

diagnosis of COVID-19.

Viral disinfectants

Considering various transmission routes

of coronavirus (that is, via cough or

respiratory droplets, or biofluids)5, one

approach to fight against the virus is through

preventing its dissemination by means of

disinfecting air, skin or surrounding

surfaces (Fig. 1).

To this end, chemical disinfectants (such

as chlorines, peroxides, quaternary amines

and alcohols) effective against a wide variety

of pathogens have been used for disinfection

and sterilization of personal protective

equipment and surfaces6. Despite promising

results from chemical disinfectants, they

are often associated with drawbacks such as

high concentration requirements for 100%

viral inhibition, limited effectiveness over

time, and possible risks to public health

and environment7,8. Consequently, metallic

nanoparticles (for example, silver, copper,

titanium dioxide nanoparticles) have been

proposed as alternatives due to their inherent

broad range antiviral activities, persistence 

and ability to be effective at much lower

dosage9,10. For instance, preliminary

evaluations showed that silver nanocluster/

silica composite coating on facial masks had

viricidal effects against SARS-CoV-211. In

another example, NanoTechSurface, Italy,

developed a durable and self-sterilizing

formula comprised of titanium dioxide

and silver ions for disinfecting surfaces12.

In a similar manner, FN Nano Inc., USA,

developed a photocatalytic coating (light

mediated) based on titanium dioxide

nanoparticles, which can decompose organic

compounds including viruses on the surface

upon exposure to light, damaging the viral

membrane12. Nanomaterials can also be

incorporated into respiratory face masks

to further increase their inhibitory effect13.

Scientists from Queensland University of

Technology, Australia, have developed a

breathable and disposable filter cartridge

from cellulose nanofibers, which were

capable of filtering particles smaller than

100 nanometres14. Alternatively, owing

to high surface-area-to-volume ratio

and their unique chemical and physical

properties, other nanomaterials (for

example, graphene) can be used to adsorb

and eliminate SARS-CoV-215. For instance,

LIGC Applications Ltd., USA, have made

a reusable mask made of microporous

conductive graphene foam that allows

the trapping of microorganisms and the

conduction of electrical charge to destroy

them16.

These nanomaterials present an

enormous potential as disinfectants

against coronavirus, mainly due to unique

attributes of nanomaterials including

intrinsic anti-viral properties such as

reactive oxygen species (ROS) generation

and photo-dynamic and photo-thermal

capabilities. Also, adverse effects of metallic

nanomaterials on human health and the

environment can be prevented by using

biodegradable nanomaterials (that is,

polymeric, lipid-based).

Viral detection

Diagnostics is a critical weapon in the

fight against this pandemic, as it is pivotal

to isolate infected individuals as early

as possible, preventing dissemination17.

Several nanotechnology-based approaches

for SARS-CoV-2 tagging and detection are

being developed (Fig. 2).

Generally, testing kits operate

based on detection of antibodies (by

enzyme-linked immunosorbent assay,

or enzyme-linked immunosorbent assay

(ELISA)) or RNA (by polymerase chain

reaction, or PCR) associated with the

virus (from nasopharyngeal swabs taken

from individuals’ noses and throats). This

relies on their surface interactions with a

complementary detection ligand or strand

in the kit18. However, these testing kits are

generally associated with problems such

as false-negative results, long response

times and poor analytical sensitivity19.

To this end, due to their extremely large

surface-to-volume ratios, nanosized

materials can instigate highly efficient

surface interactions between the sensor

and the analyte, allowing faster and more

reliable detection of the virus20. Accordingly,

a group of researchers have developed a

colloidal gold-based test kit that enables easy

conjugation of gold nanoparticles to IgM/

IgG antibodies in human serum, plasma

and whole blood samples21. However, the

targeted IgM/IgG antibodies in this kit

were not specific to COVID-19, and as a

result in some cases produced false results

associated with patients who were suffering

from irrelevant infections. Consequently,

researchers from the University of

Maryland, USA, developed a colorimetric

assay based on gold nanoparticles capped

with suitably designed thiol-modified

DNA antisense oligonucleotides specific

for N-gene (nucleocapsid phosphoprotein)

of SARS-CoV-2, which were used for

diagnosing positive COVID-19 cases

within 10 min from the isolated RNA

samples22. Such testing kits could potentially

produce promising results, however their

performance would still be affected by

quantity of the viral load. To address this

shortcoming, researchers from ETH,

Switzerland, have recently reported a

unique dual-functional plasmonic biosensor

combining the plasmonic photothermal

effect and localized surface plasmon

resonance (LSPR) sensing transduction

to provide an alternative and promising

solution for clinical COVID-19 diagnosis23.

The two-dimensional gold nano-islands

functionalized with complementary

DNA receptors provide highly sensitive

detection of the selected sequences

from SARS-CoV-2 through nucleic

acid hybridization. For better sensing

performance, thermoplasmonic heat is

generated on the same gold nano-islands

chip when illuminated at their plasmonic

resonance frequency. Remarkably, this

dual-functional LSPR biosensor exhibited

high selectivity towards the SARS-CoV-2

sequences with a detection limit as low as

0.22 pM. In other work, to achieve rapid

and accurate detection of SARS-CoV-2

in clinical samples, researchers from the

Korea Basic Science Institute developed

an ultra-sensitive field-effect transistor

(FET)-based biosensing device24. The

sensor was produced by coating graphene

sheets of the FET with a specific antibody

against SARS-CoV-2 spike protein. The FET

device could detect the SARS-CoV-2 spike

protein at concentrations of 1.31Å~10–5 pM in

phosphate-buffered saline and 1.31Å~10–3 pM

in clinical transport medium. Remarkably,

the device exhibited no measurable

cross-reactivity with Middle East respiratory

syndrome coronavirus (MERS-CoV)

antigen, indicating the extraordinary

capability of this sensor to distinguish the

SARS-CoV-2 antigen protein from those of

MERS-CoV.

Another approach that can be used for

SARS-CoV-2 and that was successfully

used with MERS-CoV, Mycobacterium

tuberculosis and human papillomavirus

consists of a paper-based colorimetric sensor

for DNA detection based on pyrrolidinyl

peptide nucleic acid (acpcPNA)-induced

silver nanoparticle aggregation25. Briefly,

in the absence of complementary DNA,

silver nanoparticles aggregate due their

electrostatic interactions with the acpcPNA

probe. However, in the presence of target

DNA, a DNA–acpcPNA duplex starts to

form which leads to dispersion of the silver

nanoparticles as a result of electrostatic

repulsion, giving rise to a detectable colour

change25. The use of aptamers and molecular

beacons instead of PNA can also represent a

potential alternative.

Other avenue where nanomaterials can

contribute to detection of SARS-CoV-2 is

the extraction and purification of targeted

molecules from biological fluids (blood and

nasal/throat samples). Thus, nanomaterials

with magnetic properties can be decorated

with specific receptors of the virus, leading

to attachment of virus molecules to the

nanoparticles that will allow their magnetic

extraction using an external magnetic field.

In this way nanomaterial-based detection

can facilitate faster and more accurate

detection of the virus even at early stages of

the infection, in large due to versatility of

surface modification of nanoparticles.

Outlook

This overview of newly developed

nanotechnology-based disinfectants and

sensors for SARS-CoV-2 lays out a blueprint

for development of more effective sensors

and disinfectants that can be implemented

for the purpose of detection, and prevention

of this and another coronavirus. More

advances in nano-based disinfectants are

needed to meet the challenges on the front

lines of patient care. On the other side, with

COVID-19 rapidly spreading and with

new foci of infection around the corner,

efficient detection is pivotal, and the rule

is to diagnose more quickly, easily and

broadly. Time is of essence when dealing

with pandemics and the two emphasized 

aspects of nanotechnology are more likely

to soon become available to the public, as

they are not associated with some of the

stricter regulations commonly associated

with vaccines. It is essential to shorten

patient-specific and community-wide

response times to determine who is infected

or not and nanotechnology products like

the ones described here will also reduce the

impact on healthcare workers by providing

faster and easy-to-use platforms that do not

require special equipment or highly trained

personnel. And this is how nanotechnology

is taking root against SARS-CoV-2, by

promoting exactly the type of wide-ranging,

integrated approaches that are essential to

control this pandemic outbreak at local,

national, and international levels.

Sepehr Talebian 1,2,3, Gordon G. Wallace1,

Avi Schroeder 4 ✉, Francesco Stellacci 5,6

and João Conde 7,8

1Intelligent Polymer Research Institute, ARC Centre

of Excellence for Electromaterials Science, AIIM

Facility, University of Wollongong, Wollongong,

New South Wales, Australia. 2Illawarra Health and

Medical Research Institute, University of Wollongong,

Wollongong, New South Wales, Australia. 3Apiam

Animal Health Pty Ltd, East Bendigo, Victoria,

Australia. 4Laboratory for Targeted Drug Delivery

and Personalized Medicine Technologies, Department

of Chemical Engineering, Technion Israel Institute

of Technology, Haifa, Israel. 5Institute of Materials,

École Polytechnique Fédérale de Lausanne (EPFL),

Lausanne, Switzerland. 6Interfaculty Bioengineering

Institute, Ecole Polytechnique Fédérale de Lausanne

(EPFL), Lausanne, Switzerland. 7NOVA Medical

School, Faculdade de Ciências Médicas, Universidade

Nova de Lisboa, Lisboa, Portugal. 8Centre for

Toxicogenomics and Human Health (ToxOmics),

Genetics, Oncology and Human Toxicology, NOVA

Medical School, Faculdade de Ciências Médicas,

Universidade Nova de Lisboa, Lisboa, Portugal.

e-mail: avids@technion.ac.il;

francesco.stellacci@epfl.ch; joao.conde@nms.unl.pt

Published online: 29 July 2020

https://doi.org/10.1038/s41565-020-0751-0

References

1. Hu, T. Y., Frieman, M. & Wolfram, J. Nat. Nanotechnol. 15,

247–249 (2020).

2. Liu, C. et al. ACS Cent. Sci. 6, 315–331 (2020).

3. Dourado, E. Accelerating Availability of Vaccine Candidates

for COVID-19 Special Edition Policy Brief (Mercatus Center

Research, George Mason University, 2020).

4. Itani, R., Tobaiqy, M. & Al Faraj, A. Theranostics 10, 5932–5942

(2020).

5. Peng, X. et al. Int. J. Oral. Sci. 12, 1–6 (2020).

6. Fathizadeh, H. et al. InfezMed 28, 185–191 (2020).

7. Wang, J. et al. Environ. Pollut. 262, 114665 (2020).

8. Liu, J., Chamakura, K., Perez-Ballestero, R. & Bashir, S. ACS

Symp. Ser. Am. Chem. Soc. 6, 129–154 (2020).

9. Shahzadi, S., Zafar, N. & Sharif, R. Antibacterial Activity of

Metallic Nanoparticles (IntechOpen, 2018).

10. Sportelli, M. C. et al. Nanomaterials 10, 802 (2020).

11. Balagna, C., Perero, S., Percivalle, E., Nepita, E. V. & Ferraris, M.

Open Ceram. 1, 100006 (2020).

12. Nanotechnology in battle against coronavirus. Statnano https://

statnano.com/nanotechnology-in-battle-against-coronavirus

(2020).

13. Weiss, C. et al. ACS Nano 14, 6383–6406 (2020).

14. Widdowson, N. New mask material can remove virus-size

nanoparticles. Phys.org https://phys.org/news/2020-04-maskmaterial-

virus-size-nanoparticles.html (2020).

15. Palmieri, V. & Pap, M. Nano Today 33, 100883 (2020).

16. Reusable graphene mask sterilises itself against Coronavirus

with electrical charge. NBIC https://statnano.com/news/67559/

Reusable-Graphene-Mask-Sterilises-Itself-against-

Coronavirus-with-Electrical-Charge (2020).

17. Cohen, J. & Kupferschmidt, K. Science 367, 727 (2020).

18. Vaculovicova, M., Michalek, P., Krizkova, S., Macka, M. & Adam,

V. Anal. Methods 9, 2375–2391 (2017).

19. Udugama, B. et al. Diagnosing COVID-19: the disease and tools

for detection. ACS Nano 14, 3822–3835 (2020).

20. Mokhtarzadeh, A. et al. Trends Anal. Chem. 97, 445–457

(2017).

21. Li Z. et al. J. Med. Virol. https://doi.org/10.1002/jmv.25727

(2020).

22. Moitra, P., Alafeef, M., Dighe, K., Frieman, M. B. & Pan, D. ACS

Nano 14, 7617–7627 (2020).

23. Qiu, G. et al. ACS Nano 14, 5268–5277 (2020).

24. Seo, G. et al. ACS Nano 14, 5135–5142 (2020).

25. Teengam, P. et al. Anal. Chem. 89, 5428–5435 (2017).

Acknowledgements

J.C. acknowledges the European Research Council Starting

Grant (ERC-StG-2019-848325). F.S. acknowledges the

Swiss National Science Foundation Sinergia Program. A.S.

acknowledges the support of ERC-STG-2015-680242 and

of the Israel Ministry of Science and Technology COVID-

19 Grant. S.T. and G.G.W. are grateful for funding from the

Australian Research Council Centre of Excellence program

(project no. CE 140100012).

Author contributions

J.C. and S.T. conceived the concept of this manuscript,

which resulted from extensive discussions among all

authors who co-wrote and co-edited the entire manuscript.

Competing interests

The authors declare no competing interests.

 

 

 

 

 

 

 

 

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