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Voltammetric study of the affinity of divalent heavy metals for guanine functionalized iron oxide nanoparticles

MetadataDetails
Publication Date2020-11-14
JournalProceedings of 7th International Electronic Conference on Sensors and Applications
AuthorsSimona Sawan, Khalil Hamze, Ali Youssef, Rayyan Boukarroum, Kamal H. Bouhadir
InstitutionsCentre National de la Recherche Scientifique, Institut des Sciences Analytiques
AnalysisFull AI Review Included

Technical Documentation & Analysis: Advanced Environmental Sensing via BDD Electrodes

Section titled “Technical Documentation & Analysis: Advanced Environmental Sensing via BDD Electrodes”

This research highlights the critical role of Boron-Doped Diamond (BDD) electrodes in developing high-performance electrochemical sensors for environmental monitoring. 6CCVD specializes in providing the high-quality MPCVD diamond substrates necessary to replicate and advance this technology.

  • Core Achievement: Successful development of a highly sensitive and reproducible voltammetric sensor for detecting divalent heavy metal ions (Cu2+, Pb2+, Cd2+).
  • Material Foundation: The sensor relies on the exceptional chemical stability and wide potential window of a Boron-Doped Diamond (BDD) electrode.
  • Functionalization: The BDD surface was functionalized with Guanine Hydrazide (GH) coated Iron Oxide (Fe3O4) nanoparticles (45 nm diameter) to enhance heavy metal affinity.
  • Performance Metrics: Excellent reproducibility was demonstrated, achieving Relative Standard Deviation (RSD) values as low as 4% for Cu(II) detection.
  • Sensitivity Range: High sensitivity was achieved in the low micromolar (”M) range, confirming the suitability of BDD for trace analysis in environmental samples.
  • 6CCVD Value Proposition: We provide the necessary high-conductivity, low-roughness BDD substrates (PCD or SCD) required for scalable, next-generation electrochemical sensor arrays.

The following hard data points were extracted from the research, demonstrating the performance characteristics of the BDD-based sensor system.

ParameterValueUnitContext
Electrode SubstrateBoron-Doped Diamond (BDD)N/AUsed for electrochemical sensing
Nanoparticle Diameter45nmAverage size of spherical Fe3O4 NPs
Adsorption Affinity OrderCu2+ > Pb2+ > Cd2+N/ADetermined electrochemically
Cu(II) Sensitivity (Range I)171.6”A/”MLinear range: 0.209 to 1.03 ”M
Pb(II) Sensitivity (Range I)156”A/”MLinear range: 0.232 to 0.809 ”M
Cd(II) Sensitivity (Range I)101.4”A/”MLinear range: 0.483 to 4.97 ”M
Cu(II) Reproducibility (RSD)4%Over five independent measurements
Pb(II) Reproducibility (RSD)5%Over five independent measurements
Cd(II) Reproducibility (RSD)10%Over five independent measurements

The experimental procedure involved a multi-step synthesis and characterization process, culminating in electrochemical analysis using the BDD platform.

  1. Nanoparticle Synthesis: Iron Oxide (Fe3O4) nanoparticles were synthesized for use as the core adsorbent material.
  2. Surface Modification: The Fe3O4 nanoparticles were coated with (3-aminopropyl) triethoxysilane (APTES) to facilitate subsequent functionalization.
  3. Functionalization: Guanine Hydrazide (GH) was elaborated onto the APTES-coated Fe3O4 nanoparticles, creating the GH-APTES-Fe3O4 composite.
  4. Structural Characterization: Fourier Transform Infrared Spectroscopy (FTIR), Energy-Dispersive X-ray Analysis (EDX), and X-ray Diffraction (XRD) were employed to confirm the successful synthesis and functionalization steps.
  5. Morphological Analysis: Scanning Electron Microscopy (SEM) was used to verify the spherical morphology and average particle diameter (45 nm).
  6. Electrode Fabrication: The synthesized GH-APTES-Fe3O4 composite was coated onto a Boron-Doped Diamond (BDD) electrode surface.
  7. Electrochemical Testing: Square Wave Voltammetry (SWV) was utilized to evaluate the electrochemical interaction and adsorption capacity of the functionalized BDD electrode toward divalent heavy metal ions.

This research validates the superior performance of BDD in advanced electrochemical sensing. 6CCVD is the global leader in supplying high-quality, custom MPCVD diamond substrates essential for scaling this technology from the lab to commercial deployment.

To replicate or extend this high-sensitivity heavy metal sensor, researchers require highly conductive and stable BDD material.

  • Primary Recommendation: Heavy Boron-Doped Polycrystalline Diamond (PCD)
    • Justification: Offers the required high conductivity (low resistivity) and chemical inertness for robust electrochemical applications, while providing cost-efficiency and large area potential (up to 125mm).
    • Specifications: We offer PCD substrates with controlled boron doping levels to optimize conductivity and minimize background current.
  • Alternative Recommendation: Heavy Boron-Doped Single Crystal Diamond (SCD)
    • Justification: Ideal for microelectrode arrays or applications demanding ultra-low surface roughness (Ra < 1 nm) and superior crystalline uniformity.

6CCVD’s MPCVD capabilities directly address the needs of advanced sensor development, offering flexibility far beyond standard commercial electrodes.

Requirement6CCVD CapabilityBenefit to Sensor Development
Substrate SizeCustom plates/wafers up to 125mm (PCD)Enables fabrication of large-scale sensor arrays and high-throughput systems.
Thickness ControlSCD/PCD thickness from 0.1”m to 500”mAllows optimization of thermal management and mechanical stability for integrated devices.
Surface FinishPolishing to Ra < 5 nm (PCD) or Ra < 1 nm (SCD)Ensures uniform coating adhesion (e.g., for GH-APTES-Fe3O4) and minimizes surface defects that cause noise.
Integrated ContactsCustom Metalization (Au, Pt, Ti, W, Cu)We can deposit necessary contact pads (e.g., Ti/Pt/Au) directly onto the BDD surface for seamless integration into potentiostats and sensor packaging.

The success of this heavy metal sensing project hinges on precise material selection and surface preparation. 6CCVD’s in-house PhD team provides expert consultation for projects involving:

  • Environmental Sensing: Optimizing BDD doping and surface termination for enhanced sensitivity in trace element detection.
  • Electrochemical Applications: Designing custom electrode geometries and metal contacts for flow cells and microfluidic systems.
  • Surface Functionalization: Advising on optimal diamond surface preparation (e.g., hydrogen or oxygen termination) to maximize the binding efficiency of functionalizing agents like APTES and Guanine Hydrazide.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly. We ship globally (DDU default, DDP available) to accelerate your research.

View Original Abstract

The smallest concentrations of heavy metal ions can be harmful to both the environment and human health. They are non-biodegradable and can accumulate all along the food chain, thus their onsite monitoring and removal is of great importance. In this work, a novel material based on (3-aminopropyl)triethoxysilane (APTES) coated iron oxide (Fe3O4) nanoparticles functionalized with guanine hydrazide (GH) was elaborated. Fourier transform infrared spectroscopy, energy-dispersive X-ray analysis and X-ray diffraction were used to control the synthesis and functionalization steps of the nanoparticles. The morphology and particle size were studied by scanning electron microscopy. Spherical nanoparticles with an average diameter of 45 nm were obtained. A boron-doped diamond electrode coated with GH-APTES-Fe3O4 nanoparticles was used to evaluate the electrochemical interaction of some divalent heavy metal ions with guanine hydrazide. Adsorption isotherms were investigated electrochemically and it was shown that the adsorption capacity of the nanoparticles towards heavy metals decreased in the following order: Cu2+>Pb2+>Cd2+. Moreover, the signals generated by square wave voltammetry exhibited two distinct linear response ranges; the first linear plot lies in the range of 0.209 to 1.03 ΌM with a sensitivity of 171.6 ”A/”M for Cu (II), 0.232 to 0.809 ΌM with a sensitivity of 156 ”A/”M for Pb (II) and 0.483 to 4.97 ΌM with a sensitivity of 101.4 ”A/”M for Cd (II). Furthermore, an excellent reproducibility was achieved with relative standard deviation (RSD) values of 4%, 5% and 10% respectively over five independent measurements.