ao1c04198_si_001.pdf (277.41 kB)
Download fileEfficient Preparation of a Nonenzymatic Nanoassembly Based on Cobalt-Substituted Polyoxometalate and Polyethylene Imine-Capped Silver Nanoparticles for the Electrochemical Sensing of Carbofuran
journal contribution
posted on 2022-01-03, 13:04 authored by Amna Yaqub, Syeda Rubina Gilani, Sehrish Bilal, Akhtar Hayat, Anila Asif, Saadat Anwar SiddiqueThe ever-growing
exploitation of pesticides and their lethal effects
on living beings have made it a dire need of the day to develop an
accurate and reliable approach for their monitoring at trace levels.
The designing of an enzyme-free electrocatalyst to electrochemically
detect the pesticide residues is currently gaining much importance.
In this study, a novel redox-sensing film was constructed successfully
based on cobalt-substituted Dawson-type polyoxometalate [P2W17O61 (Co2+·OH2)]7– (Co-POM) and polyethylene imine (PEI)-capped
silver nanoparticles (AgNPs). A nanohybrid assembly was fabricated
on a glassy carbon electrode’s surface by alternately depositing
Co-POM and PEI-AgNPs using the layer-by-layer self-assembly method.
The surface morphology of the immobilized CoPOM/AgNP multilayer nanoassembly
was analyzed through scanning electron microscopy along with energy-dispersive
spectroscopy for elemental analysis. The redox properties and surface
morphologies of fabricated assemblies were evaluated by cyclic voltammetry
and electrochemical impedance spectroscopy. The practicability and
feasibility of the proposed sensing layer was tested for the detection
of a highly toxic insecticide, that is, carbofuran. The fabricated
sensor exhibited a limit of detection of 0.1 mM with a sensitivity
of 13.11 μA mM–1 for carbofuran. The results
depicted that the fabricated nonenzymatic hybrid film showed excellent
electrocatalytic efficiency for the carbofuran oxidation. Furthermore,
the obtained value of “apparent Km”, that is, 0.4 mM,
illustrates a good electro-oxidation activity of the sensor for the
detection of carbofuran. The exceptionally stable redox activity of
Co-POM, high surface area and greater conductivity of AgNPs, and the
synergistic effect of all components of the film resulted in an excellent
analytical performance of the proposed sensing assembly. This work
provides a new direction to the progress and designing of nonenzymatic
electrochemical sensors for pesticide determination in real samples.
History
Usage metrics
Categories
Keywords
nonenzymatic nanoassembly basedhighly toxic insecticideexcellent analytical performanceconstructed successfully basedcapped silver nanoparticlesagnp multilayer nanoassemblynonenzymatic electrochemical sensors61 sub2 sub17 sub11 μa mmelectrochemical impedance spectroscopyhigh surface areaalternately depositing co7 – supproposed sensing assemblyproposed sensing layerfabricated sensor exhibitedelectrochemical sensingsensing filmdispersive spectroscopynanohybrid assemblyassembly method4 mm1 mmwork providestype polyoxometalatetrace levelssynergistic effectsurface morphologysurface morphologiessubstituted polyoxometalatesubstituted dawsonresults depictedreliable approachredox propertiesreal samplespolyethylene iminepesticide residuespesticide determinationoxidation activityobtained valuenovel redoxnew directionliving beingslethal effectslayer selfimmobilized copomgrowing exploitationgreater conductivitygood electrofree electrocatalystfilm resultedfabricated assemblieselemental analysiselectrochemically detectefficient preparationdire needcyclic voltammetry