A sensitive electrochemical aptasensor for highly specific detection of streptomycin based on the porous carbon nanorods and multifunctional graphene nanocomposites for signal amplification

Quantitative detection of antibiotic residues in animal food stuffs is of great significance. In this work, a highly sensitive electrochemical aptasensor for the sensitive detection of streptomycin antibiotic was fabricated based on a novel signal amplification strategy. Specifically, this aptasensor was constructed utilizing porous carbon nanorods (PCNR) formed by porous carbon nanosphere and multifunctional graphene composite (GR–Fe 3 O 4 –AuNPs) as biosensing substrate. PCNR samples with large specific pore volume and high specific surface area were successfully prepared by hydrothermal and chemical activation treatment for the first time. GR–Fe 3 O 4 –AuNPs was served as labels to achieve a high sensitivity and low limit of detection (LOD). Under the optimized conditions, the proposed aptasensor exhibited a high sensitivity and a wider linearity to streptomycin in the range 0.05–200   ng/mL with a low detection limit of 0.028   ng/mL. The proposed aptasensor displayed an excellent analytical performance with great reproducibility, high selectivity and stability. In addition, the as–prepared aptasensor was successfully utilized for the determination of streptomycin in real samples.