The invention discloses a method for detecting
tetracycline residues in milk and drinking water and belongs to the technical field of
food safety. The method comprises the following steps of: constructing a detection
system with known
tetracycline concentration to obtain a light absorption difference
standard curve, fitting the curve to obtain a regression equation, mixing milk or drinking water to be detected with an
acetic acid solution to obtain a
mixed solution, centrifuging and layering the
mixed solution to obtain a supernatant liquid, adding a
tetracycline aptamer solution, adding a nanogold solution after incubation, finally adding positive
ion electrolyte, determining the difference of the light adsorption rates at the 650nm part and the 520nm part of an
electrolyte standard solution and a blank control solution by a
microplate reader, and calculating the content of the tetracycline in milk and drinking water to be detected under the control of the equation obtained by fitting the
standard curve. The method is high in speed, low in cost, high in sensitivity, good in selectivity, and convenient to operate without depending on large-sized instruments or equipment, the lowest
detection limit is 45.8nM, the defects that the existing
aptamer is time-
wasting due to marking and high in cost are overcome and the method has the advantages of high speed, sensitivity and low cost.