Colorimetric Sensing Patch Based on Cyanidin-3-O-glucoside/HAMA Microneedles for Rapid Detection of Meat Spoilage

Food safety is essential for protecting public health. This study introduces a novel microneedle (MN) patch that employs a pH-responsive colorimetric mechanism for the real-time, easy, and visible detection of meat freshness. The patch is a pH-responsive colorimetric microneedle (C3G/HAMA@MN) patch composed of eco-friendly bio-based components, specifically methacryloylated hyaluronic acid (HAMA) and cyanidin-3-O-glucoside (C3G). Its mechanical strength reaches 7 N per needle, capable of penetrating over 85% of meat tissue. The distinctive structural design allows the microneedle tip to quickly and directly penetrate the meat tissue, extracting interstitial fluid in situ and promptly transferring it to the backing layer. The backing layer visually indicates pH changes in real time. The color change from light to dark matches freshness levels at different deterioration stages. Without sophisticated instruments, consumers may notice the patch's color change in two minutes using their vision, allowing for simple and reliable food quality inspection. A powerful new instrument for on-site food safety monitoring combines real-time display, easy interpretation, and biodegradable materials.