Abstract
Salicylic acid (SA) is widely used in food storage, preservatives, additives, healthcare, and the pharmaceutical industry. However, various poisoning symptoms are frequently reported upon ingestion of a large amount of SA. Therefore, discovering new tools for sensing SA with fast, simple, and portable performance is imperative. Herein, five rhodamine-based fluorescent sensors were constructed, and investigated their SA detection profiles. Probe 1 was excellent selective with a rapid response, highly sensitive (LOD = 2.5 μM), good interference resistance, and unaided eye recognition. The spray experiment and paper-based test strips indicating that probe 1 enables to the on-site and quantitatively detect SA on actual food surfaces by using a smartphone identifying the RGB values. The sensing performance was validated in soil samples, water, and various agricultural food samples. Overall, the constructed SA sensor can function as a promising, convenient, and affordable tool for point-of-care detection of SA in diversiform environmental samples.