Narrow Results

In this paper, we report the preparation and characterization of a sensitive and reusable nonenzymatic glucose (NEG) sensor based on copper nanowires (CuNWs)/polyaniline (PANI)/reduced graphene oxide (rGO) nanocomposite ink. The CuNWs/PANI/rGO nanocomposite ink was prepared by solvothermal mixing of CuNWs, PANI, rGO and binders. The X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier Transform Infra-Red (FT-IR) spectroscopy techniques were used to assess the structural and morphological parameters of prepared nanocomposite ink. The cyclic voltammetry (CV) technique was used to estimate the electrochemical behavior of prepared NEG sensor. The structural, morphological and spectroscopy results confirmed the change in morphological and oxidation state of CuNWs to CuO nanostructures as a constituent of nanocomposite ink. The CuO nanostructures supported on PANI/rGO demonstrated good electrochemical stability and great electrocatalytic activity toward glucose oxidation. At a glucose oxidation potential of 0.64V, the prepared NEG sensor exhibited great electrocatalytic ability by offering a high sensitivity of 843.06$\mu$AmM${}^{-1}$cm${}^{-2}$ in the linear glucose range 0–4mM with a lower detection limit of 1.6mM. In addition to these outstanding performance characteristics, CuNWs/PANI/rGO nanocomposite ink-based NEG sensor has the advantages of ease of fabrication, low cost and reusability.

This work demonstrated the preparation and characterization of a novel 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) derivative containing boronic acid group and investigation of its non-invasive/non-enzymatic fluorescence sensor behavior for determination of glucose. The novel BODIPY derivative bearing boronic acid pinacol ester (BODIPY-1) was synthesized by Sonogashira coupling reaction between Iodo-BODIPY and 4-ethynylphenylboronic acid pinacol ester. The target novel BODIPY-2 compound which was used as a fluorescence probe for the determination of glucose was synthesized from BODIPY-1by changing the pinacol ester group to the boric acid moieties. The fluorescence intensity of the BODIPY-2 fluorophore decreased when it interacted with the glucose. Sensing performance towards to glucose of this probe was evaluated in detail concerning the suitable solvent, linear concentration range, convenient pH, limit of detection (LOD), limit of quantification (LOQ) and selectivity. The LOD value of BODIPY-2 was found 0.19 mM toward glucose. Also, the complex stoichiometry between the BODIPY-2 and glucose molecules was determined by Job’s plot technique.

The Ni-metal-organic frameworks microspheres (Ni-BTC) were prepared and used directly to construct non-enzymatic glucose sensors. The Ni-BTC sensors displayed much higher glucose sensing performance than that of Ni-MOFs derived NiO, which showed wide detection regions of 5–3000$\mu$M and 3500–6000$\mu$M with the sensitivity of 932.68$\mu$A$\cdot$mM${}^{-1}\cdot$cm${}^{-2}$ and 273.04$\mu$A$\cdot$mM${}^{-1}\cdot$cm${}^{-2}$, respectively. Moreover, it also displayed good selectivity and favorable sensing feasibility for serum analysis. The high performance of the non-enzymatic glucose detection on Ni-BTC may be due to the highly efficient charge transfers during the electrocatalytic glucose oxidation process.

NiO/Pt nanotubes were obtained by firstly preparing the NiO nanotube with self-sacrificial templating methods and subsequently loading Pt nanoparticles with microwave assistant procedures. The as-prepared NiO/Pt nanotubes sensors displayed better electrocatalytic activities for glucose oxidation. The detection limit and sensitivity for glucose detection are 0.3 $\mu$M and 418.28 $\mu$A⋅ mM${}^{-1}$⋅cm${}^{-2}$ in the range of 1 $\mu$M-4000 $\mu$M. In addition, the practicality of NiO/Pt nanotubes was also confirmed by determining the glucose in serum specimen.

Over the past decade, the development of non-enzymatic electrochemical biosensors had thriven at a considerable rate. Compared with the traditional enzymatic electrochemical biosensors, the non-enzymatic electrochemical biosensors have the advantages of higher sensitivity and stability. Recently, plenty of researches have devoted to synthesizing new materials, such as bimetallic nanoparticles, and also develop specific nanostructures on the sensor surface to solve the problem of poisoning and increase the selectivity. This work develops two non-enzymatic glucose sensors that are based on nanostructured Pt–Ir films which were deposited by electrodeposition. Because of the relatively high deposition current density, bubbles produced vigorously on the working electrode surface. This phenomenon results in leaf-like nanostructure formed naturally on the surface of the working electrode and further increased the catalytic reaction area. Besides, as determined by the sampling analysis method that is developed herein, the presented Pt–Ir sensors mitigate the current drifting problem which is easily observed when a constant potential is applied in an amperometric glucose detection. Furthermore, the presented Pt–Ir sensors show high sensitivity and stability in 1X PBS (0.15 M NaCl) at 37°C in the glucose concentration range of 1–12 mM. Therefore, the presented non-enzymatic glucose sensors not only provide great potential in biomedical applications, such as homecare products, but can also be adapted for the biological application, such as continuous cell culture monitoring.