An intelligent meat spoilage sensor based on Cu-doped carbonized polymer dots

Accurate and real-time detection of biogenic amines is vital for food safety, yet developing sensors that combine selectivity with environmental stability remains a challenge. Here, we report a new strategy using copper-integrated, self-assembled carbonized polymer dots (Cu-CPDs) to overcome these limitations. Here we introduce a novel strategy in which Cu²⁺ active sites are precisely anchored within the self-assembled supramolecular framework of carbonized polymer dots (Cu-CPDs), yielding a robust colorimetric chemosensor. X-ray photoelectron spectroscopy and controlled experiments confirm that the sensing mechanism relies on specific Cu²⁺-NH₃ coordination chemisorption rather than non-specific physisorption, endowing the Cu-CPDs with exceptional selectivity towards amines. The sensor maintains stable performance at different temperatures and relative humidity up to 90%, delivering a rapid linear colorimetric response suitable for on-site spoilage monitoring of protein-rich foods. More importantly, this work also provides a generalizable sensor design paradigm that leverages the self-assembled CPDs matrix to host functional metal sites, addressing critical limitations in chemical sensing.