Materials and Equipment
Comprehensive list of all required components, chemicals, enzymes, and laboratory equipment for the dual-electrode glutamine sensor prototype.
Materials and Equipment for Dual-Electrode Glutamine Sensor Prototyping
This document provides a comprehensive list of all materials, chemicals, enzymes, and equipment required for the fabrication and testing of the dual-electrode glutamine sensor prototype. All items are categorized by function and include specifications, recommended suppliers, and approximate quantities needed for a typical laboratory-scale prototyping process (approximately 10-20 sensor units).
1. Electrode Base Materials
- Screen-printed carbon electrode (SPCE) substrates
- Specifications: Dual working electrode configuration on ceramic or polyester substrate
- Dimensions: 3.4 × 1.0 cm total size, with 4 mm diameter working electrodes
- Recommended suppliers: DropSens (DRP-C1110), Pine Research, or Metrohm
- Quantity: 20-30 units
- Silver/silver chloride reference electrode ink
- Specifications: Screen-printable Ag/AgCl paste
- Recommended suppliers: Gwent Electronic Materials, DuPont
- Quantity: 5-10 g
- Carbon conductive ink
- Specifications: Screen-printable carbon paste
- Recommended suppliers: Gwent Electronic Materials, DuPont
- Quantity: 10-15 g
- Electrode connector cables
- Specifications: Compatible with screen-printed electrode edge connectors
- Recommended suppliers: DropSens (CAC), Pine Research
- Quantity: 2-3 units
2. Nanomaterials for Electrode Modification
- Multi-walled carbon nanotubes (MWCNTs)
- Specifications: Outer diameter 10-20 nm, length 10-30 μm, >95% purity
- Recommended suppliers: Sigma-Aldrich, Nanostructured & Amorphous Materials Inc.
- Quantity: 1 g
- Copper oxide nanoparticles (CuO NPs)
- Specifications: Size 40-80 nm, >99% purity
- Recommended suppliers: Sigma-Aldrich, US Research Nanomaterials
- Quantity: 1 g
- Chitosan
- Specifications: Medium molecular weight, 75-85% deacetylated
- Recommended suppliers: Sigma-Aldrich
- Quantity: 5 g
3. Enzymes and Enzyme Immobilization Materials
- Glutaminase
- Specifications: From E. coli, lyophilized powder, ≥40 units/mg protein
- Recommended suppliers: Sigma-Aldrich, Megazyme
- Quantity: 100-250 units
- Glutamate oxidase
- Specifications: From Streptomyces sp., lyophilized powder, ≥5 units/mg solid
- Recommended suppliers: Sigma-Aldrich, Creative Enzymes
- Quantity: 25-50 units
- Bovine serum albumin (BSA)
- Specifications: Lyophilized powder, ≥96% purity
- Recommended suppliers: Sigma-Aldrich, Thermo Fisher Scientific
- Quantity: 1 g
- Glutaraldehyde
- Specifications: 25% solution in water
- Recommended suppliers: Sigma-Aldrich, Thermo Fisher Scientific
- Quantity: 10 mL
- Safety note: Handle in fume hood with appropriate PPE
4. Membrane and Protective Layer Materials
- Nafion
- Specifications: 5% w/w solution in lower aliphatic alcohols/water mixture
- Recommended suppliers: Sigma-Aldrich, Fuel Cell Store
- Quantity: 5 mL
- Polyurethane
- Specifications: Medical-grade, aliphatic polyether urethane
- Recommended suppliers: AdvanSource Biomaterials, DSM Biomedical
- Quantity: 5 g
- Tetrahydrofuran (THF)
- Specifications: Anhydrous, ≥99.9% purity
- Recommended suppliers: Sigma-Aldrich, Thermo Fisher Scientific
- Quantity: 100 mL
- Safety note: Handle in fume hood with appropriate PPE
5. Chemicals and Reagents
- L-Glutamine
- Specifications: ≥99% purity
- Recommended suppliers: Sigma-Aldrich, Thermo Fisher Scientific
- Quantity: 5 g
- L-Glutamic acid
- Specifications: ≥99% purity
- Recommended suppliers: Sigma-Aldrich, Thermo Fisher Scientific
- Quantity: 5 g
- Phosphate buffered saline (PBS)
- Specifications: 0.1 M PBS, pH 7.4, tablets or powder
- Recommended suppliers: Sigma-Aldrich, Thermo Fisher Scientific
- Quantity: For preparation of 2 L solution
- Potassium ferricyanide
- Specifications: ≥99% purity
- Recommended suppliers: Sigma-Aldrich, Thermo Fisher Scientific
- Quantity: 5 g
- Potassium ferrocyanide
- Specifications: ≥99% purity
- Recommended suppliers: Sigma-Aldrich, Thermo Fisher Scientific
- Quantity: 5 g
- Hydrogen peroxide
- Specifications: 30% w/w solution in water
- Recommended suppliers: Sigma-Aldrich, Thermo Fisher Scientific
- Quantity: 25 mL
- Safety note: Store at 2-8°C, handle with appropriate PPE
- Acetic acid
- Specifications: Glacial, ≥99.7% purity
- Recommended suppliers: Sigma-Aldrich, Thermo Fisher Scientific
- Quantity: 100 mL
- Safety note: Handle in fume hood with appropriate PPE
- Ethanol
- Specifications: Absolute, ≥99.5% purity
- Recommended suppliers: Sigma-Aldrich, Thermo Fisher Scientific
- Quantity: 500 mL
- Isopropanol
- Specifications: ≥99.5% purity
- Recommended suppliers: Sigma-Aldrich, Thermo Fisher Scientific
- Quantity: 250 mL
- Deionized water
- Specifications: Resistivity ≥18.2 MΩ·cm at 25°C
- Source: Laboratory water purification system
- Quantity: 5 L
6. Laboratory Equipment
- Potentiostat/galvanostat
- Specifications: Capable of cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy
- Recommended models: Gamry Interface 1010E, CH Instruments 760E, Metrohm Autolab PGSTAT204
- Quantity: 1 unit
- Ultrasonic bath
- Specifications: Frequency 40 kHz, with temperature control
- Recommended suppliers: Branson, VWR
- Quantity: 1 unit
- Analytical balance
- Specifications: Readability 0.1 mg, capacity 100-200 g
- Recommended suppliers: Mettler Toledo, Sartorius
- Quantity: 1 unit
- pH meter
- Specifications: Accuracy ±0.01 pH, with temperature compensation
- Recommended suppliers: Mettler Toledo, Thermo Fisher Scientific
- Quantity: 1 unit
- Micropipettes
- Specifications: Set of adjustable volume pipettes (0.5-10 μL, 10-100 μL, 100-1000 μL)
- Recommended suppliers: Eppendorf, Gilson
- Quantity: 1 set
- Vortex mixer
- Specifications: Variable speed control
- Recommended suppliers: VWR, Thermo Fisher Scientific
- Quantity: 1 unit
- Magnetic stirrer with heating
- Specifications: Temperature range up to 340°C, speed range 50-1500 rpm
- Recommended suppliers: IKA, Thermo Fisher Scientific
- Quantity: 1 unit
- Laboratory oven
- Specifications: Temperature range up to 250°C, with digital control
- Recommended suppliers: Thermo Fisher Scientific, VWR
- Quantity: 1 unit
- Refrigerator (2-8°C) and freezer (-20°C)
- Specifications: Laboratory grade with temperature monitoring
- Recommended suppliers: Thermo Fisher Scientific, VWR
- Quantity: 1 unit each
- Fume hood
- Specifications: Standard laboratory fume hood with adequate ventilation
- Required for handling volatile chemicals and glutaraldehyde
- Quantity: 1 unit
7. Consumables and Miscellaneous Items
- Microcentrifuge tubes
- Specifications: 1.5 mL and 2.0 mL, polypropylene
- Recommended suppliers: Eppendorf, VWR
- Quantity: 100 each
- Pipette tips
- Specifications: Compatible with micropipettes, various sizes
- Recommended suppliers: Eppendorf, VWR
- Quantity: 1 box each size
- Glass beakers
- Specifications: Borosilicate glass, various sizes (50 mL, 100 mL, 250 mL)
- Recommended suppliers: Pyrex, VWR
- Quantity: 2 each size
- Volumetric flasks
- Specifications: Class A, various sizes (10 mL, 50 mL, 100 mL, 1 L)
- Recommended suppliers: Pyrex, VWR
- Quantity: 2 each size
- Magnetic stir bars
- Specifications: PTFE-coated, various sizes
- Recommended suppliers: VWR, Thermo Fisher Scientific
- Quantity: 5-10 assorted
- Parafilm
- Specifications: Standard laboratory sealing film
- Recommended suppliers: Bemis, VWR
- Quantity: 1 roll
- Laboratory gloves
- Specifications: Nitrile, powder-free, various sizes
- Recommended suppliers: VWR, Thermo Fisher Scientific
- Quantity: 1 box
- Safety goggles
- Specifications: Chemical splash protection
- Recommended suppliers: 3M, VWR
- Quantity: 1-2 pairs
- Laboratory coat
- Specifications: Standard laboratory coat
- Recommended suppliers: VWR, Thermo Fisher Scientific
- Quantity: 1-2 units
- Fine-tip tweezers
- Specifications: Stainless steel, anti-static
- Recommended suppliers: VWR, Thermo Fisher Scientific
- Quantity: 2-3 pairs
- Precision scissors
- Specifications: Fine-point, stainless steel
- Recommended suppliers: VWR, Thermo Fisher Scientific
- Quantity: 1-2 pairs
- Disposable plastic syringes
- Specifications: 1 mL and 5 mL
- Recommended suppliers: BD, VWR
- Quantity: 20 each
- Syringe filters
- Specifications: 0.22 μm, PVDF membrane
- Recommended suppliers: Millipore, VWR
- Quantity: 20 units
- Laboratory notebook
- Specifications: Bound, numbered pages
- Recommended suppliers: VWR, Thermo Fisher Scientific
- Quantity: 1 unit
8. Optional Equipment for Advanced Characterization
- Scanning electron microscope (SEM)
- For morphological characterization of electrode surfaces
- Access through institutional core facilities if not available in-house
- Fourier-transform infrared spectroscopy (FTIR)
- For confirmation of enzyme immobilization
- Access through institutional core facilities if not available in-house
- X-ray photoelectron spectroscopy (XPS)
- For surface elemental analysis
- Access through institutional core facilities if not available in-house
9. Storage and Handling Considerations
The following storage conditions are recommended for key materials:
- Enzymes: Store at -20°C in small aliquots to avoid repeated freeze-thaw cycles
- Glutaraldehyde: Store at 2-8°C in tightly sealed container
- Hydrogen peroxide: Store at 2-8°C away from light and combustible materials
- Nanomaterials: Store in sealed containers at room temperature in a desiccator
- Screen-printed electrodes: Store at room temperature in a clean, dry environment
Note: All materials should be of analytical or higher grade. For chemicals and reagents, higher purity generally results in better sensor performance and reproducibility. Always check the expiration dates of enzymes and reactive chemicals before use.