Controllable Synthesis of Pd-ZIF-L-GO: The Role of Drying Temperature

Optimized Fabrication of Bimetallic ZnCo Metal-Organic Framework at NiCo-Layered Double Hydroxides for Multiple Storage and Capability Synergy All-Solid-State Supercapacitors

Rational design and structural regulation of hybrid nanomaterials with superior electrochemical performance are crucial for developing sustainable energy storage platforms. Among these materials, NiCo-layered double hydroxides (NiCo-LDHs) demonstrate an exceptional charge storage capabilities owing to their tunable 2D lamellar structure, large interlayer spacing, and rich redox electrochemically active sites. However, NiCo-LDHs still suffer from sever agglomeration of their particles with limited charge transfer rates, resulting in an inadequate rate capability. In this study, bimetallic ZnCo-metal organic framework (MOF) tripods were grown on the surface of NiCo-LDH nanowires, which significantly reduced the self-agglomeration and stacking of the NiCo-LDH nanowire arrays, offering more accessible active sites for charge transfer and shortening the path for ion diffusion. The fabricated hybrid ZnCo-MOF@NiCo-LDH and its individual counterparts were tested as supercapacitor electrodes. The ZnCo-MOF@NiCo-LDH electrode demonstrated a remarkable specific capacitance of 1611 F g^-1 at 2 A g^-1 with an enhanced rate capability of 66% from 2 to 20 A g^-1. Moreover, an asymmetric all solid-state supercapacitor device was constructed using ZnCo-MOF@NiCo-LDH and palm tree-derived activated carbon (P-AC) as positive and negative poles, respectively. The constructed device can store a high specific energy of 44.5 Wh Kg^-1 and deliver a specific power of 876.7 W Kg^-1 with outstanding Columbic efficiency over 10,000 charging/discharging cycles at 15 A g^-1.

MOF-Derived Cu-BTC Nanowire-Embedded 2D Leaf-like Structured ZIF Composite-Based Aptamer Sensors for Real-Time In Vivo Insulin Monitoring

Insulin, which is a hormone produced by the β-cells of the pancreas, regulates the glucose levels in the blood and can transport glucose into cells to produce glycogen or triglycerides. Insulin deficiency can lead to hyperglycemia and diabetes. Therefore, insulin detection is critical in clinical diagnosis. In this study, disposable Au electrodes were modified with copper(II) benzene-1,3,5-tricarboxylate (Cu-BTC)/leaf-like zeolitic imidazolate framework (ZIF-L) for insulin detection. The aptamers are easily immobilized on the Cu-BTC/ZIF-L composite by physical adsorption and facilitated the specific interaction between aptamers and insulin. The Cu-BTC/ZIF-L composite-based aptasensor presented a wide linear insulin detection range (0.1 pM to 5 μM) and a low limit of detection of 0.027 pM. In addition, the aptasensor displayed high specificity, good reproducibility and stability, and favorable practicability in human serum samples. For the in vivo tests, Cu-BTC/ZIF-L composite-modified electrodes were implanted in non-diabetic and diabetic mice, and insulin was quantified using electrochemical and enzyme-linked immunosorbent assay methods.

2D leaf-like ZIF-L decorated with multi-walled carbon nanotubes as electrochemical sensing platform for sensitively detecting thiabendazole pesticide residues in fruit samples

Excessive use of pesticides in modern agriculture results in large amounts of pesticide residues in agricultural production, greatly threatening human health. Herein, novel two-dimensional leaf-like zeolitic imidazolate framework-L decorated with multi-walled carbon nanotubes (MWCNTs/ZIF-L) was prepared by a facile solvent way and exploited as electrode material for sensitive electrochemical sensing of thiabendazole (TBZ). Two-dimensional ZIF-L presents high surface area, large pore volume, and abundant active sites, which exhibits high enrichment ability towards TBZ molecules, while the MWCNTs interspersed on ZIF-L can prominently enhance the electron transport capability and improve the electrocatalytic activity for TBZ oxidation. Due to the intriguing synergy between the components, the MWCNTs/ZIF-L-based electrochemical sensor reveals a limit of detection (LOD) of 6.0 nmol·L^-1, which is lower than that reported in most literatures. Additionally, satisfactory reproducibility and repeatability, long-term stability, and excellent selectivity are acquired. The proposed method was also applied for the detection of TBZ in apple and orange samples with acceptable recoveries.