Overview
- Researchers reported in ACS Sensors a four-by-four microneedle array coated with gold nanoparticles and an HX-reactive enzyme that reads electrical changes linked to freshness.
- In validation on salmon pieces left at room temperature for up to 48 hours, the device tracked rising hypoxanthine levels that correlate with spoilage progression.
- The prototype detected HX below 500 parts per billion, a level associated with very fresh fish, and delivered results in roughly 100 seconds.
- Sensitivity in laboratory comparisons matched a commercially available lab testing kit, indicating performance on par with established assays.
- The device remains a prototype intended for future portable use, with further engineering, calibration across species, and broader validation still required.