Non-destructive detection of trans-caryophyllene in early sweetpotato black spot disease using a QCM gas sensor based on modified CAU-1@ZIF-8 composite

Changes in the content of trans -caryophyllene could identify whether sweetpotatoes are infected with black spot disease. Therefore, in this study, a quartz crystal microbalance (QCM) sensor based on modified CAU-1@ZIF-8 was used for non-destructive detection of sweetpotato black spot. The experimental results showed that the constructed sensor performed best when both modified CAU-1 and ZIF-8 were present. The sensor showed a linear trend (R 2  = 0.996, limit of detection (LOD) = 0.55 ppm) in response to trans -caryophyllene in the concentration range of 20–340 ppm with a sensitivity of −0.489 Hz (ppm) −1 . The developed gas sensor was successfully used for the detection of trans -caryophyllene in real samples of sweetpotato. The experimental data showed a significant correlation with the results of gas chromatography-mass spectrometry (GC–MS) with a correlation coefficient of 0.970 ( p  < 0.01). Therefore, it could be used for early warning of black spot disease in sweetpotato.