▎ 摘　　要

Since Gram-negative bacteria have a predominant role in nosocomial infections, there are high demands to develop a fast and sensitive method for diagnosis of bacteria in clinical samples. To address this challenge, we designed a novel electrochemical biosensor based on aptamers immobilized in engineered zeolitic imidazolate Framework-8 (ZIFs-8) via EDC-NHS chemistry. Cyclic voltammetry and electrochemical impedance spectroscopy techniques were conducted to monitor the electrochemical characterization. With respect to unique pi-pi interactions between aptamer and graphene oxide (GO), the differential pulse voltammetry technique was applied with ferrocene-graphene oxide (Fc-GO) as an electroactive indicator for the detection of Pseudomonas aeruginosa (P. aeruginosa). In the presence of P. aeruginosa, the configuration of the aptamer showed a change and Fc-GO was released from the electrode surface. On the basis of the signal-off strategy, the proposed biosensor exhibits a wide linear dynamic range (from 1.2 x 10(1) to 1.2 x 10(7) CFU mL(-1)) with a low detection limit. The results reveal that the fabricated aptasensor has high potential applicability in the field of monitoring disease therapy and controlling the safety of the clinical sites.