Recently,more sensitive methods for analysis of clenbuterol (CL) are required,because of potential risk and illegal use of CL as a hazard to human health.Lateral flow assays (LFAs) have been used as a reliable,rapid,and cost effective on-site screening technique for the simultaneous determination of CL.However,the available lateral flow assay for CL requires a competitive format,leading to low sensitivity of detection when judged by naked eyes.In this study,we reported a novel dual-functional LFA for monitoring CL in terms of fluorescence-quenching effect of gold nanoparticles (AuNPs).The most important feature of this novel LFA is its dual function as a fluorescence assay under excitation light,but under natural light as an AuNPs LFA.It is apparent that signal intensity of the T-line is associated with elevated level of CL.In the “turn on” mode when results observed by naked eyes with excitation light,the sensitivity of detection reached 0.04 ng/mL.Whereas,in “turn off” mode using a traditional AuNPs LFAs,results are determined under natural light,the sensitivity decreased to 5 ng/mL.This novel LFAs could be used for a variety of small analytes such as pesticides,persistent organic pollutants,explosives,toxins,medicinal and abused drugs,hormones,etc.