Size Discrimination of Carbohydrates via Conductive Carbon Nanotube@Metal Organic Framework Composites

Abstract

Traditional chemical sensing methodologies have typically relied on the specific chemistry of the analyte for detection. Modifications to the local environment surrounding the sensor represent an alternative pathway to impart selective differentiation. Here, we present the hybridization of a 2-D metal organic framework (Cu3(HHTP)2) with single-walled carbon nanotubes (SWCNTs) as a methodology for size discrimination of carbohydrates. Synthesis and the resulting conductive performance are modulated by both mass loading of SWCNTs and their relative oxidation. Liquid gated field-effect transistor (FET) devices demonstrate improved on/off characteristics and differentiation of carbohydrates based on molecular size. Glucose molecule detection is limited to the single micromolar concentration range. Molecular Dynamics (MD) calculations on model systems revealed decreases in ion diffusivity in the presence of different sugars as well as packing differences based on the size of a given carbohydrate molecule. The proposed sensing mechanism is a reduction in gate capacitance initiated by the filling of the pores with carbohydrate molecules. Restricting diffusion around a sensor in combination with FET measurements represents a new type of sensing mechanism for chemically similar analytes.

Controllable Construction of Two-Dimensional Conductive M3(HHTP)2 Nanorods for Electrochemical Sensing of Malachite Green in Fish

“…In summary, the M 3 (HHTP) 2 crystals synthesized in this study had high crystallinity, without obvious accumulation and vortex layer disorder. As illustrated in the spectra of Fourier transform infrared spectroscopy (FT-IR) (Figure E), M 3 (HHTP) 2 had typical peaks of ν­(CO) and ν­(C–O) at 1621 and 1214 cm –1 . ,, The new peak of ν­(CO) appeared at 1621 cm –1 . These results indicated that M 3 (HHTP) 2 had been synthesized successfully, and there was a strong interaction between the skeletons.…”

“…As illustrated in the spectra of Fourier transform infrared spectroscopy (FT-IR) (Figure 2E), M 3 (HHTP) 2 had typical peaks of ν(C�O) and ν(C−O) at 1621 and 1214 cm −1 . 21,47,48 The new peak of Further structural and composition characterization of Cu 3 (HHTP) 2 were performed. As displayed in transmission electron microscopy (TEM) images (Figure 3A,B), Cu 3 (HHTP) 2 was a rod-like structure.…”

Size-Based Norfentanyl Detection with SWCNT@UiO-MOF Composites

“…A series of carbohydrates with different molecular sizes was discriminated using FET devices made up of SWCNT@Cu 3 (HHTP) 2 . 26 The sensing mechanism of the SWCNT@MOF FET devices is unique. Unlike conventional FET SWCNT sensors that rely on the electrostatic effect of the analyte to alter CNT conductance, SWCNT@MOF FET sensing operates by controlling gate capacitance through the inhibition of ion transportation to SWCNT surfaces, accomplished by the analyte molecules obstructing the MOF channels.…”

“…Furthermore, our recent report showcased the application of the SWCNT@MOF in liquid-gated FET devices for the first time. A series of carbohydrates with different molecular sizes was discriminated using FET devices made up of SWCNT@Cu 3 (HHTP) 2 …”

Metal–Organic Frameworks on Palladium Nanoparticle–Functionalized Carbon Nanotubes for Monitoring Hydrogen Storage

“…There are two general strategies to increase the electrical conductivity of a MOF. The metal and linker chemistry can be tuned to incorporate conductive pathways through the MOF with redox-active linkers and an extended conjugated network, or the MOF can be combined with conductive material such as one-dimensional carbon nanotubes and two-dimensional MXenes (metal carbides, nitrides, or carbonitrides). − The combination of MOF and carbon nanotubes has previously been shown to combine the best of these two properties and form nanocomposites that have a high electrical conductivity of carbon nanotubes and the high absorption capacity of a MOF including synergetic improvement in gas-adsorption capacity. , …”