A Portable Photoelectric Sensor Based on Colloidal Gold Immunochromatographic Strips for Rapid Determination of Clenbuterol in Pig Urine

Colloidal gold immunochromatographic strips for the determination of clenbuterol (CLB) were developed based on the principle of immune competitive inhibition. Clenbuterol competes for the specific binding site on the CLB antibody with the conjugated compound of clenbuterol and bovine serum albumin (BSA) immobilized on the strip as the testing dot, and thus results in the decrease or disappearance of the coloration of the testing dot on the strip. The sensing system was easily established by inserting the test strip into the slot of the portable photoelectric sensor. The concentration of CLB was obtained from the calculation of the intensity of the reflected light. The results showed that the response of the photoelectric sensor to concentration of clenbuterol displayed a linear correlation over a range from 1 to 10 μg L−1 with a detection limit of 0.05 μg L−1, and the recovery reached 85.46%–96.05% in the pig urine samples. The photoelectric sensor based on the colloidal gold immunochromatography strips for the detection of clenbuterol demonstrates the advantage of easy operation, short detecting time, favorable sensitivity and specificity.