Rapid detection of linalool by QCM gas sensor based on HKUST-1/MWCNT-gel@MIP in early sweetpotato black spot disease

Linalool, a terpenoid alcohol with bacteriostatic properties, was detected in sweetpotato suffering from black spot disease. In this research, a composite material based on HKUST-1/MWCNT-gel@MIP was employed to detect the linalool content in these infected sweetpotatoes. The micro-morphology and crystal structure of the composite were characterized using scanning electron microscopy (SEM), fourier transform infrared (FTIR), and x-ray diffraction (XRD). Experimental results demonstrated that the quartz crystal microbalance (QCM) gas sensor of HKUST-1/MWCNT-gel@MIP composite exhibited high sensitivity (0.873 Hz/ppm), a low detection limit (0.237 ppm), a small standard deviation (0.83 %), good reproducibility, and outstanding selectivity. The QCM gas sensor data from actual samples showed a strong correlation with gas chromatography-mass spectrometry (GC–MS) results (r = −0.976, p < 0.01), demonstrating its exceptional ability to identify linalool. Thus, it can be used for early detection of sweetpotato black spot disease.