A QCM immunosensor to rapidly detect ractopamine using bio-polymer conjugate and magnetic β-cyclodextrins

•An ultrasensitive QCM immunosensor was constructed for rapid detection of ractopamine (RAC) in fodder using magnetic β-cyclodextrins and bio-polymer conjugated, sandwich-type, piezoelectric immunosensors.•A polyenzyme (HRP)-antibody conjugate, Powervision, served as a signal label to amplify the signal.•Instead of using primary antibodies, magnetic β-CD was used to capture and enrich RAC from a fodder matrix, which was then used as a biosensor platform to further amplify the detection response.