NanoImpact 28 (2022) 100430
Available online 4 October 2022
2452-0748/© 2022 Elsevier B.V. All rights reserved.
Coated Cu-doped ZnO and Cu nanoparticles as control agents against plant
pathogenic fungi and nematodes
Panagiota Tryfon
a
, Nathalie N. Kamou
b
, Nikoletta Ntalli
c
, Stefanos Mourdikoudis
d, e
,
Katerina Karamanoli
f
, Dimitrios Karfaridis
g
, Urania Menkissoglu-Spiroudi
b, *
,
Catherine Dendrinou-Samara
a, *
a
Laboratory of Inorganic Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
b
Pesticide Science Laboratory, School of Agriculture, Faculty of Agriculture Forestry and Natural Environment, Aristotle University of Thessaloniki, 54124 Thessaloniki,
Greece
c
Analytical Chemistry and Pesticides Laboratory, Department of Agriculture Crop Production and Rural Environment, University of Thessaly, Volos, Greece
d
UCL Healthcare Biomagnetic and Nanomaterials Laboratories, 21 Albemarle Street, London W1S 4BS, United Kingdom
e
Biophysics Group, Department of Physics and Astronomy, University College London (UCL), London, United Kingdom
f
Laboratory of Agricultural Chemistry, Faculty of Agriculture, Forestry and Natural Environment, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
g
Physics Department, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
A R T I C L E INFO
Keywords:
Metal-based nanoparticles
Plant protection
Botrytis cinerea
Sclerotinia sclerotiorum
Meloidogyne javanica
ABSTRACT
In the current study, coated copper nanoparticles with polyethylene glycol 8000 (Cu@PEG NPs) and copper-
doped zinc oxide nanoparticles with diethylene glycol (Cu-doped ZnO@DEG NPs) have been synthesized via
solvothermal and microwave-assisted process, physicochemical characterized, and studied as nano-fungicides
and nano-nematicides. Spheroidal Cu-doped ZnO@DEG NPs and urchin-like Cu@PEG NPs have been isolated
with average crystallite sizes of 12 and 21 nm, respectively. The Cu doping (11.3 wt%) in ZnO lattice (88.7 wt%)
was investigated by Rietveld refnement analysis and confrmed by X-ray Diffraction (XRD) and X-ray Photo-
electron Spectroscopy (XPS). The Cu-doped ZnO@DEG and Cu@PEG NPs revealed a growth inhibition of fungi
Botrytis cinerea (B. cinerea) and Sclerotinia sclerotiorum (S. sclerotiorum) and nematode paralysis of Meloidogyne
javanica in a dose-dependent manner. Cu-doped ZnO@DEG NPs were more effective against M. javanica (EC
50
=
2.60 μg/mL) than the Cu@PEG NPs (EC
50
= 25 μg/mL). In contrast, the antifungal activity was approximately
similar for both NPs, with EC
50
values at 310 and 327 μg/mL against B. cinerea, respectively, and 260 and 278
μg/mL against S. sclerotiorum, respectively. Lettuce (Lactuca sativa) plants were inoculated with S. sclerotiorum or
M. javanica and sprayed with either Cu-doped ZnO@DEG NPs or Cu@PEG NPs. The antifungal effect was
evaluated based on a disease index (DI), and nematicidal activity was assessed based on the total number of galls
and nematode females per root gram. NPs successfully inhibited the growth of both pathogens without causing
phytotoxicity on lettuce. The DI were signifcantly decreased as compared to the positive control (DI = 5.2),
estimated equal to 1.7, 2.9 and 2.5 for Cu@PEG NPs, Cu-doped ZnO@DEG NPs and the chemical control
(KOCIDE 2000), respectively. The reduction in galling and population of M. javanica ranged from 39.32% to
32.29%, statistically like chemical control. The treatment of lettuce plants with Cu-doped ZnO@DEG NPs
increased the leaf net photosynthetic value at 4.60 and 6.66 μmol CO
2
2
s
1
in plants inoculated with
S. sclerotiorum and M. javanica, respectively, as compared to the control (3.00 μmol CO
2
2
s
1
). The antioxidant
capacity of NPs treated lettuce plants was evaluated as 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging
activity in leaf extracts. Plants inoculated with S. sclerotiorum and sprayed with Cu-doped ZnO@DEG and
Cu@PEG NPs, exhibited a 34.22% and 32.70% increase in antioxidant capacity, respectively, higher than the
control. Similarly, an increase in antioxidant capacity was measured (39.49 and 37.36%) in lettuce inoculated
with M. javanica and treated with Cu-doped ZnO@DEG and Cu@PEG NPs, respectively. Moreover, an increase of
phenolic compounds in lettuce leaf tissue treated with NPs was measured as compared to the control. Overall,
* Corresponding authors.
E-mail addresses: rmenkis@agro.auth.gr (U. Menkissoglu-Spiroudi), samkat@chem.auth.gr (C. Dendrinou-Samara).
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https://doi.org/10.1016/j.impact.2022.100430
Received 27 July 2022; Received in revised form 23 September 2022; Accepted 26 September 2022