How to Validate CV, EIS, and Potentiometric Modes on an Electrochemical ASIC

How to Validate CV, EIS, and Potentiometric Modes on an Electrochemical ASIC

The goal is simple:

Demonstrate that the ASIC can correctly drive and measure real electrochemical transducers, without unnecessary complexity or bespoke development programmes.

Phase One: Electrical Stand-Ins (The Correct Starting Point)

Early validation typically replaces electrochemical sensors with:

  • A precision resistor (e.g. 1 MΩ)
  • A controlled voltage source

This phase is essential because it:

  • Isolates the analogue front end
  • Verifies DAC/ADC performance
  • Confirms waveform generation and timing
  • Removes chemical and surface variability

✅ This approach should always be replicated in-house before introducing real sensors.

Moving Beyond Stand-Ins

What “Real Sensor Validation” Actually Means

Once the electrical behaviour is confirmed, teams often assume they must jump straight to:

  • Hormone sensors
  • Enzyme-functionalised biosensors
  • Application-specific chemistry

In reality, this is not required to validate ASIC-level functionality.

Instead, validation should answer a simpler question:

Can the ASIC generate correct electrochemical waveforms and measure realistic current and impedance responses?

This can be demonstrated using standard electrodes and well-characterised solutions.

Validating Cyclic Voltammetry (CV)

What CV Validation Requires

To electrochemically validate CV capability, you only need:

  • A stable working electrode
  • A known redox system

No analyte-specific biosensors are necessary.

Recommended Items:

Carbon working electrodes Carbon electrodes provide a robust, repeatable surface for CV experiments. 👉 Hyper-value Carbon 501 electrodes https://shop.zimmerpeacock.com/en-gb/products/hyper-value-501-carbon-electrode?variant=40553384411210

Redox test solution A ferri/ferrocyanide solution produces:

  • Clear oxidation and reduction peaks
  • Highly repeatable CV curves

👉 Potassium hexacyanoferrate(III) solution https://shop.zimmerpeacock.com/en-gb/products/potassium-hexacyanoferrateiii-solution

Optional (but recommended): Cleaning solution Used to refresh the electrode surface and improve curve quality. 👉 Cleaning solution https://shop.zimmerpeacock.com/en-gb/products/cleaning-solution

What This Demonstrates

This setup validates:

  • Voltage sweep accuracy
  • Scan-rate control
  • Peak formation and symmetry
  • Current measurement stability under real electrochemical load

✅ This is sufficient to prove CV mode works as intended.

Validating Electrochemical Impedance Spectroscopy (EIS)

A key insight:

The same electrodes and solutions used for CV can also be used for EIS.

There are no dedicated “EIS sensor kits.” EIS validation is inherently system-level.

Using the same setup, teams can validate:

  • Frequency-dependent impedance magnitude
  • Phase response
  • Double-layer capacitance effects
  • Non-ideal behaviour beyond a simple resistor model

✅ This makes EIS the natural extension of resistor-based validation.

Potentiometric Sensors: Why Substrate Choice Matters

Ceramic vs Polymer Substrates

Early electrochemical sensors were commonly built on ceramic substrates due to their stability and lab-friendly properties.

However:

  • Ceramic wafers are physically small
  • They limit manufacturing throughput
  • They are less aligned with scalable, disposable products

Transition to Polymer (Flexible) Sensors

To enable high-volume manufacturing, modern sensor platforms increasingly use polymer-based flexible substrates, which offer:

  • Larger sheet sizes
  • Better scalability
  • Lower cost at volume
  • Compatibility with wearables and disposables

Recommended Potentiometric Sensor for Validation

For potentiometric validation aligned with scalable manufacturing, a flexible pH sensor is recommended.

👉 pH sensor on flexible material (hyper-value range) https://shop.zimmerpeacock.com/en-gb/products/ph-on-flexible-material

This sensor allows teams to:

  • Validate potentiometric front-end performance
  • Work with a manufacturable sensor format
  • Avoid investing effort in legacy ceramic designs unless required

✅ It is a better representative of future commercial products.

Why Hormone Sensors Are Not Required at This Stage

Hormone sensors (e.g. cortisol, progesterone):

  • Are application-specific
  • Require specialised surface chemistry
  • Are typically accessed through funded development programmes

For ASIC-level validation, they add complexity without improving confidence in:

  • CV waveform generation
  • EIS measurement accuracy
  • Potentiometric input behaviour

They are best introduced after core electrochemical capability is proven.

One Setup, Multiple Measurement Modes

A common concern is whether each electrochemical mode requires separate hardware.

In practice, the same electrodes and solutions support:

  • CV
  • EIS

Potentiometric sensors are swapped in as needed, and only software parameters change.

This keeps validation:

  • Cost-effective
  • Fast
  • Easy to replicate across teams

Outcome: From Validation to Deployment

Following this staged approach allows teams to:

  • Replicate prior external deliverables internally
  • Extend electrical stand-ins to real electrochemistry
  • Confidently integrate sensors with a MAX-class evaluation kit

In this case, the validation path concluded successfully with the purchase of all remaining equipment and readiness to begin hands-on testing with real sensors.

Summary: Minimal Ordering List for ASIC Validation

This minimal, well-scoped setup is sufficient to validate CV, EIS, and potentiometric modes on a modern electrochemical ASIC—without bespoke programmes or unnecessary complexity.

Measurement ModeRecommended ItemsCVCarbon 501 electrodes + ferri/ferrocyanideEISSame electrodes & solutionPotentiometryFlexible pH sensorRepeatabilityCleaning solution (optional)

This minimal, well-scoped setup is sufficient to validate CV, EIS, and potentiometric modes on a modern electrochemical ASIC—without bespoke programmes or unnecessary complexity.