Rapid and ultrasensitive detection of biogenic amines with colorimetric sensor array

Biogenic amine (BA) is an appropriate indicator of food spoilage. Thus, it is important to develop simple, portable and highly sensitive amine sensors for food safety. Here, detection of biogenic amines was investigated using a colorimetric sensor array fabricated from complexes of pH-sensitive dyes and nanomaterials. The Brønsted-Lowry acid-base reaction between the complex and BAs forms different amine salts. Variation in the alkalinity of these amines causes significant and distinct color changes in the pH-sensitive dyes. Eight common BAs can be differentiated from visual observation of difference maps alone. In conjunction with pattern recognition, the sensor array clearly differentiates eight gaseous amines with ≥92.6% accuracy and allows rapid quantification of trimethylamine (TMA) vapors with an impressive limit of detection (LOD) of 1.3 ppb. It also shows excellent chemical stability against changes in temperature and humidity. This sensor array for amines can be used as an alternative and promising tool for food monitoring.