Development of fluorescent probes that can monitor foodstuff hazards is highly desirable. Herein we report the first example of an AIEgen probe (QM-TPA), conjugated by a quinoline-malononitrile (QM) scaffold and triphenylamine unit, for direct sensing of triacylglycerol polymers in frying oil, enabling a rapid probing, on-site analysis, and portable operation in food inspection applications.