High-performance field-effect transistor glucose biosensors based on bimetallic Ni/Cu metal-organic frameworks

Accurate detection of glucose is essential for the diagnosis of diabetes, wherein effective and sensitive biosensors for glucose detection are needed. Here, we fabricated a glucose sensor based on field-effect transistor (FET) with bimetallic nickel-copper metal-organic frameworks (Ni/Cu-MOFs) as its channel layers which were grown in-situ through a simple one-step hydrothermal method and modified with glucose oxidase (GOD) by using glutaraldehyde (GA) as linkers. Due to the synergistic effect of Ni ions and Cu ions in MOFs, the sensor (GOD-GA-Ni/Cu-MOFs-FET) showed good field effect performance and great responses to glucose through enzymatic reactions. It displayed a piecewise linear relationship in the wide range (1 μM–20 mM), and provided high sensitivity (26.05 μAcm−2mM−1) in the low concentration (1–100 μM) and a low detection limit (0.51 μM). The sensor also had these advantages of high specificity, excellent reproducibility, good short-term stability and fast response time. Especially, it is indicated that the Ni/Cu-MOFs-FETs with high performance have the potential to be available sensors, paving the way for the application of bimetallic MOFs in biosensing. Ions from the enzymatic reaction of glucose accumulated on the surface of bimetallic MOFs films, inducing the change of charges concentration. [Display omitted] •One simple in situ growth method was proposed to prepare field effect transistor biosensors.•Bimetallic Ni/Cu metal organic frameworks were used to prepare biosensors.•The performance of Ni/Cu metal organic frameworks was adjusted by metal molar ratio.•Detecting glucose with high specificity, excellent reproducibility and fast response time.