A portable, reusable, and highly sensitive colorimetric probe for rapid screening of meat freshness

Timely detection of meat spoilage is essential for ensuring food safety and public health. To enable rapid on-site assessment of meat freshness, we designed a colorimetric probe, BCY-OH, to monitor biogenic amines, which are established biomarkers of meat spoilage. BCY-OH undergoes a distinct color transition from yellow to purple upon interaction with cadaverine, and is characterized by a large Stokes shift (109 nm), a rapid response (16 s), excellent selectivity, and high sensitivity (LOD = 0.18 μM). BCY-OH was further fabricated into portable test strips for detecting gaseous cadaverine. The strips exhibited a gradual color change from yellow to purple upon exposure to increasing cadaverine vapor concentrations (0–54.4 ppm). This colorimetric signal remained stable for ten days and allowed for at least four reuse cycles after regeneration with acidic vapor treatment. Furthermore, an intelligent sensing platform based on smartphone RGB analysis was established to enable real-time freshness assessment of shrimp, pork, and chicken. The proposed method was validated against the standard total volatile basic nitrogen method. Therefore, this work provides a simple, portable, and sustainable tool for food safety screening, which is practical for both consumers and food quality control officers.