Label-Free Electrochemical Aptasensor Based on Stone-like Gold Nanoparticles for Ultrasensitive Detection of Tetracycline

The widespread use of tetracycline (TET) for controlling bacterial infections has led to its residues and accumulation in animal food and the environment, which leads to a serious threat to food safety and environmental protection. Therefore, it is essential to develop a sensitive method to detect the residue TET. In this work, the stone-like Au nanoparticles (SL-AuNPs) possessing a large size and large exposed active surfaces were prepared with a porous N-doped carbon aerogel (NCA) featuring high N atom content and a large specific surface area. Combining the advantages of NCA and SL-AuNPs, the co-assembly of SL-AuNPs and NCA (NCA@SL-AuNPs) enables it to be an ultrasensitive electrochemical aptasensor for tetracycline (TET) detection with a larger linear range (10(-15)-10(-11) M) and a lower detection limit (3.2 x 10(-16) M) than the previously reported aptasensor. Importantly, NCA@SL-AuNPs also exhibit excellent performance for detecting TET in milk.