Novel Fe-based metal-organic framework (MOF) modified carbon nanofiber as a highly selective and sensitive electrochemical sensor for tetracycline detection

In this work, a novel electrochemical aptasensor based on Fe-based MOFs was fabricated. To enhance sensitivity to the detection of antibiotics, NH2-MIL-101(Fe)/CNF@AuNPs was synthesized by a combination of hydrothermal, electrospinning, pyrolysis and electrodeposition methods. Subsequently aptamer could be attached to the NH2-MIL-101(Fe)/CNF@AuNPs through "Au-S" bonds. The electrical signals generated from the interaction between antibiotics and aptamers were amplified by the NH2-MIL-101(Fe)/CNF@AuNPs aptasensor, resulting in a significant current/impedance response. Thus, signal generation and amplification were successfully realized. In addition, the Box-Behnken Design (BBD) strategy was adopted to optimize the detection conditions and greatly reduce experimental errors. Under optimized conditions, the tetracycline concentration detected by the sensor had a linear relationship with the impedance in the range of 0.1-105 nM TC. The lowest detection limit was 0.01 nM. NH2-MIL-101(Fe)/CNF electrospinning aptasensor exhibited good selectivity and stability. Furthermore, quantitative detection of tetracycline was achieved in real water samples. The sensor reported here could become a promising new strategy for detecting tetracycline in environmental water samples in the future.