Dual-Indicator loaded porous polymer microneedle patches for rapid and colorimetric detection of water-injected meat

Water-injected meat leads to microbial growth, which affects the health of consumers. A colorimetric porous polymer microneedle patch was designed and prepared using photopolymerization of an acrylate monomer with porogen to be the substrate, and cobalt (II) chloride as color change indicator and tartrazine as the reference. The color of the microneedle patch changed from green to yellow green and to yellow as the increase of moisture concentration. Furthermore, the discoloration trend of the microneedle patch during the moisture measurement of meat is very regular. The moisture measurement of meat in range of 66.9 %-75.7 % exhibited a good linear dependence on RGB values. The results indicate that the microneedle patch can visually determine the moisture content of meat in 3 min. In addition, the microneedle patch can be combined with smartphone to achieve accurate detection of water-injected meat, making it a wonderful tool in the field of food safety testing.