Construction of aptamer sensor based on Au nanozymes for ultrasensitive SERS detection of tobramycin

Tobramycin aptamer was adsorbed on the surface of gold nanoparticles (Au NPs) by van der Waals forces, hydrogen bonds, and other factors, limiting nanozyme peroxidase activity. Because tobramycin has a higher affinity for the tobramycin aptamer, including tobramycin in Au@Apts nanozymes was able to dislodge the aptamer from the surface of Au NPs and restore the catalytic activity of nanozymes. Raman spectroscopy of the enzyme-catalyzed product TMBox can detect this shift in enzyme activity. The restored value of nanozyme activity increased with tobramycin concentration and had a good linear correlation in the concentration range of 10−10∼10−1 M with a detection limit of 2.04 × 10−11 M. Aptamer biosensors are built using the SERS platform, which has the advantages of high sensitivity, high precision, and a wide detection range. It is prospectively employed in food safety and the detection of antibiotic residues.