An electrochemical aptasensor was developed for the detection of kanamycin based on the synergistic contributions of chitosan–gold nanoparticles (CS–AuNPs), graphene–gold nanoparticles (GR–AuNPs) and multi-walled carbon nanotubes–cobalt phthalocyanine (MWCNTs–CoPc) nanocomposites. The aptasensor was prepared by sequentially dripping CS–AuNPs, GR–AuNPs and MWCNTs–CoPc nanocomposites onto a gold electrode (GE) surface. During the above process, these nanomaterials showed a remarkable synergistic effect towards the aptasensor. CS–AuNPs, GR–AuNPs and MWCNTs–CoPc as the nanocomposites mediator improved electron relay during the entire electron transfer process and the aptasensor response speed. The electrochemical properties of the modified processes were characterized by cyclic voltammetry (CV). The morphologies of the nanocomposites were characterized by scanning electron microscopy (SEM). The experimental conditions such as the concentration of the aptamer, the time, temperature and the pH were optimized. Based on the synergistic contributions of CS–AuNPs, GR–AuNPs and MWCNTs–CoPc nanocomposites, the proposed aptasensor displayed high sensitivity, high specificity, a low detection limit (5.8 × 10⁻⁹ M) (S/N = 3) and excellent stability. It was successfully applied to the detection of kanamycin in real milk spiked samples.

A simple, low-cost, and sensitive 3D microfluidic origami electrochemiluminescence aptamer-device was developed based on a novel gold nanoparticle modified porous paper working electrode for point-of-care diagnosis.

In this work, we report a novel sandwich-type electrochemical aptasensor for sensitive and selective detection of antibiotic kanamycin. This aptasensor was constructed by assembling graphene–polyaniline (GR–PANI) and polyamidoamine dendrimer–Au nanoparticle (PAMAM–Au) nanocomposites on the surfaces of a glass carbon electrode, which as electrode materials exhibited excellent charge-transport property and loading capacity of biomolecules. Followed by the sandwich-type specific identification, kanamycin detection was realized by outputting a redox current from electro-reduction reaction of H₂O₂ catalyzed by HRP. It was demonstrated that the developed strategy had a wide linear response range from 5 × 10⁻⁶ to 4 × 10⁻² μg mL⁻¹ and a low detection limit of 4.6 × 10⁻⁶ μg mL⁻¹. Additionally, this aptasensor had the advantages in its low cost, high sensitivity, and superb specificity. Thus, it might provide a useful tool for kanamycin determination and related food safety analysis and clinical diagnosis.