Rapid and sensitive detection of β-agonists using a portable fluorescence biosensor based on fluorescent nanosilica and a lateral flow test strip.

A portable fluorescence biosensor with rapid and ultrasensitive response for Clenbuterol (CL) has been built up with fluorescent nanosilica and a lateral flow test strip. Quantitative detection of CL was realized by recording the fluorescence intensity of fluorescent nanosilica captured on the test line. The sensing results indicated that the sensitivity of the fluorescent nanosilica-based strip was better than that of conventional colloidal gold-based strips. The visual limit of detection of the strip for qualitative detection was 0.1 ng/mL while the LOD for quantitative detection could down to 0.037 ng/mL by using fluorescence biosensor. The recoveries of test samples were from 89.3% to 97.7%. The assay time for CL detection was less than 8 min, suitable for rapid testing on-site.