How to Improve the Anti-Interference Capability of Electrode Sensors?

Common Interferents and Their Mechanisms of Impact

The accuracy of electrochemical detection has long been challenged by coexisting interferents. In blood glucose testing, for example, whole-blood samples commonly contain ascorbic acid (vitamin C), uric acid, and acetaminophen, whose oxidation potentials are close to that of the glucose reaction product (such as hydrogen peroxide). These substances are directly oxidized at the working electrode, generating additive current that falsely elevates readings. The degree of interference typically varies with interferent concentration, applied potential, and electrode surface condition—rough or non-uniform surfaces further amplify this nonspecific response. Blood ketone (β-hydroxybutyrate), lactate, and uric acid assays face similar electroactive interferents. Anti-interference performance is therefore a key criterion for whether an electrochemical biosensor can enter clinical and home settings.

Mainstream Anti-Interference Strategies

Over years of development, the industry has built a layered set of anti-interference approaches:

• Selective membranes: functional films such as Nafion or cellulose acetate coated on the electrode surface, using charge repulsion or size exclusion to block interferents from reaching the electrode;
• Nanomaterial modification: gold nanoparticles, carbon nanotubes, Prussian blue, and other nanomaterials that lower the detection potential of the target analyte, avoiding the oxidation window of interferents;
• Dual working-electrode differential design: pairing an enzyme-loaded working electrode with an enzyme-free (or inert-protein) reference electrode on the same strip, subtracting background interference from the differential signal;
• Enzyme engineering: enzymes or electron-mediator systems with higher selectivity for the target analyte, reducing side reactions at the source.

These strategies are often used in combination, and whether they can be implemented reliably ultimately depends on the manufacturing quality of the electrode substrate.

The Foundational Role of Precious-Metal Sputtered Electrodes

Every surface-modification strategy requires an electrode surface that is inherently uniform, clean, and reproducible. Magnetron sputtering deposits precious-metal films such as gold and platinum in vacuum, with precisely controlled thickness (±5% on Huili Biotech's lines), producing dense, smooth surfaces free of the organic residues found in printing inks—an ideal anchoring substrate for functional membranes and nanomaterial coatings. Strong film-to-substrate adhesion prevents modified layers from detaching during storage and testing, and high batch-to-batch consistency (batch CV ≤ 5%) ensures that the anti-interference design reproduces stably on every production lot. In short, electrode-manufacturing precision sets the ceiling for anti-interference performance.

Test and Validation Methods for Anti-Interference Performance

Anti-interference designs must be verified through systematic experiments. Commonly used methods include:

• Interference-coefficient (IK) testing: adding specified interferent concentrations (e.g., ascorbic acid 3 mg/dL, uric acid 20 mg/dL, acetaminophen 20 mg/dL) at a standard analyte concentration and calculating the response deviation;
• Linear range and limit of detection: confirming that the change in calibration slope before and after interferent addition stays within acceptable limits;
• Potential-scan optimization: using cyclic voltammetry and chronoamperometry to select a working potential that avoids interferent oxidation peaks;
• Batch-to-batch and storage stability: re-measuring interference coefficients across lots and under accelerated aging to verify design robustness.

These methods also align with the interferent-testing requirements of domestic and international standards for glucose and ketone monitoring systems, and form an important basis for product registration and quality control.

Huili Biotech's Anti-Interference Solutions

Leveraging its nanoscale magnetron sputtering platform, Huili Biotech (Changzhou) Co., Ltd. provides anti-interference-oriented electrode solutions for blood glucose, blood ketone, uric acid, and lactate testing: high-purity (Au ≥ 99.99%) sputtered gold electrodes and platinum electrodes serve as functional substrates on which customers can apply selective membranes and nanomaterial coatings; ±5% film-thickness control and batch CV ≤ 5% allow anti-interference designs to move stably from R&D to mass production. Combined with OEM/ODM response times of 1–2 weeks for samples and 2–4 weeks for batch delivery, Huili Biotech helps customers complete interference validation and product iteration with greater ease. We welcome discussions with our technical team on electrode selection and anti-interference strategies for your specific projects.