Covid-19 testing using nanoparticles

2. • Nanotechnology is a known field of research and was
presented by Nobel laureate Richard P. Feynman during
his well famous 1959 lecture
‘‘There’s Plenty of Room at the Bottom” (Feynman, 1960).
• Nanoparticles (NPs) are wide class of materials that include
particulate substances, which have one dimension less than
100 nm at least. ( overall shape these materials can be 0D,
1D, 2D or 3D ).
• Importance: size can influence the physiochemical
properties of a substance e.g. the optical properties.
• A 20- nm gold (Au), platinum (Pt), silver (Ag), and
palladium (Pd) NPs have characteristic wine red color,
yellowish gray, black and dark black colors, respectively.

3. • The outbreak of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2, aka COVID-19) has emerged very
rapidly and has already invaded more than 197 countries worldwide, with more than 53.9M cases and ∼1.31 M deaths
till date and increasing , as reported by the WHO.
• About 97.5% of patients develop symptoms of COVID-19 within 11.5 days of exposure, causing late diagnosis and a
high infection rate.
• Coronaviruses (CoVs) : RNA, enveloped viruses grouped into the α-CoVs, β-CoVs,
γ-CoVs, and δ-CoVs genera. β-CoVs infect mammals, with SARS-CoV-1 and
MERS-CoV as the known species able to infect humans until last year.
• Recently, SARS-CoV-2 emerged as a new species able to infect humans and
currently causing the COVID-19 pandemic
• The molecular tests used so far to confirm COVID-19 are considered the gold
standards for SARS-CoV-2 testing. Nevertheless, they require a swab sample and
a time consuming laboratory procedure.
• Shipping of samples and overload of laboratory facilities.
• Delay of many days until the test results are available.
• Local community transmission.

5. RT-PCR is recognized as a high quality and consistently employed tool to analyze and quantify the different
RNA’s in the labs and clinical diagnostics due to elevated sensitiveness in RNA amplification.
Even though, RT-PCR assisted techniques have been extensively applied in COVID-19 detection, their
applicability in precise detection of virus and outbreak control is relentlessly hindered due to time taking processes
and man-power requirement. (Skilled personnel's).
The pure quantification of nucleic acid extracts from the complexive specimens are the main requirement for
potential RT-PCR analysis [6].
The lower efficiency of the extraction may result in the unfortunate indications through the amplification process
and consequently appears in the wrong diagnosis.
Conventional techniques for nucleic acid binding consist many steps which are lengthy, time taking and
susceptible to impurities.
In the supervision and controlling of impulsive epidemics like COVID-19, these conventional techniques may
consume heavy man-power, however, lacking efficient detection with a higher risk of cross-infections.

6.  Magnetic nanoparticles (MNP’s) assisted extraction techniques are convenient, simple and companionable
with automotive processes.
 The surface functionalized MNP’s adsorbs the nucleic acid from the lysis solution and are quickly isolated
from most of the contaminations with the help of external magnetic field.
 Nucleic acid can be further isolated from the functionalized surface of MNP’s by desorption process in
eluent.
 Still this consists of several steps, which is insufficient for practical detection.
 A more simple and modernize MNP’s assisted RNA-extraction protocol where MNP’s of zinc ferrite (ZNF)
were fabricated by the cost efficient sol-gel auto-combustion route and subsequently, its surface was
functionalized with carboxyl containing polymers (CPoly).
 Zinc ferrite : high chemical stability, soft magnetic behaviour (Coercivity), easy preparation, biocompatible
nature.
 Powerful interface among nucleic acids and carboxyl groups, the surface functionalized MNP’s facilitate
speedy and potential adsorption of viral RNA’s

7. 1.)Nitrates of metal ions (Zn2+, Fe3+) + citric acid
(C6H8O7) dissolved in DD water. Continuously
stirred for half an hour
2.) pH adjusted to the 7 by adding liquid ammonia.
3.) Continuously stirred , heated at 80° C until it
gets converted into gel.
5.) After gel formed, heat was raised to 120°C
which resulted in the auto combustion of the gel to
form a fluffy loose powder.
6.) Powder was grinded , sintered at 600°C for 4 h
to acquire good crystallinity.
7.) Sintered ZNF NP’s then used to prepare silica-
coated ZNF NP’s (ZNF@Si).
8.) Continuously stirred for 3 h at 27°C to form as
silica layer on the core of ZNF NP’s. The silica
modified ZNF NP’s then accumulated using
magnet.

8. 9.) APTES was added drop-by-drop in the
solution, containing the mixture of ZNF@Si
and isopropanol and ultrasonicated for 4 h
to modify the surface of ZNF@Si with NH2.
10.) NH2 modified ZNF@Si
(ZNF@Si@NH2) then accumulated using
magnet.
11.) ZNF@Si@NH2 was inserted into the
DMSO solution and subsequently mixed
with 3 g of carboxyl-modified PVA (CPoly)
and then ultrasonicated for 15 min.
12.) CPoly functionalized ZNF@Si@NH2
(ZNF@Si@NH2 @CPoly) then accumulated
using magnet.
More about APTES:
https://www.sigmaaldrich.com/catalog/pro
duct/aldrich/440140?lang=en&region=IN

10. The sensors are composed of different gold nanoparticles linked to organic ligands, creating a
diverse sensing layer that can swell or shrink upon exposure to volatile organic compounds
(VOCs), causing changes in the electric resistance.
In these layers, the inorganic nanomaterial's are responsible for the electrical conductivity,
with the organic film element providing sites for the adsorption of VOCs.
When exposed, VOCs diffuse into the sensing layer or fall on the sensing surface and react
with the organic segment or the functional groups capping the inorganic nanomaterial's.
The outcome of the interactions causes a volume change (swelling/shrinkage) in the
nanomaterial film.
As a result, the contacts among the inorganic nanomaterial block the change (higher/lower)
with an increase/decrease of conductivity.
The nanomaterial layer exposure to VOCs causes a swift charge transfer to/from the inorganic
nanomaterial, producing variations in the measured conductivity
 Different sensors can be used, due to the chemical diversity of the functional group(s)
capping the nanoparticle

11. Figure (a) Example of breath
collection with the developed hand-
held breathalyzer system from a
patient in Wuhan, China.
Figure(b) Representative response of
a sensor to three different breath
samples. The normalized response
of sensor 7 of the breathalyzer
system to three different samples:
patient A, COVID-19, first sample
while infected; patient A, second
sample after determined as
recovered; and a healthy control. The
x-axis represents the cycle
measurement; each unit is one cycle
of the sensor. The infected sample
had a positive change response,
while the recovered and control
showed negative charges

12. REFRENCES:
• MATERIALS RESEARCH INNOVATIONS
https://doi.org/10.1080/14328917.2020.1769350
Multifunctional nano-magnetic particles assisted viral RNA-extraction
protocol for potential detection of COVID-19 Sandeep B. Somvanshia ,
Prashant B. Kharata,b, Tukaram S. Sarafa , Saurabh B. Somwanshic ,
Sumit B. Shejulc and Kamalakar M. Jadhav.
ARTICLE HISTORY Received 28 April 2020 Accepted 11 May 2020.
• Multiplexed Nanomaterial-Based Sensor Array for Detection of
COVID-19 in Exhaled Breath Benjie Shan,△ Yoav Y. Broza,△ Wenjuan
Li,△ Yong Wang, Sihan Wu, Zhengzheng Liu, Jiong Wang, Shuyu
Gui, Lin Wang, Zhihong Zhang, Wei Liu, Shoubing Zhou, Wei Jin,
Qianyu Zhang, Dandan Hu, Lin Lin, Qiujun Zhang, Wenyu Li,
Jinquan Wang, Hu Liu,* Yueyin Pan,* and Hossam Haick*