Urchin-like PtNPs@Bi2S3: synthesis and application in electrochemical biosensor

Novel urchin-like Pt nanoparticles@Bi2S3 composite materials were prepared by a simple route. The composite nanomaterial was used to modify an electrode for the immobilization of enzyme molecules to construct a sensitive electrochemical biosensor.

The dependence of Cu2O morphology on different surfactants and its application for non-enzymatic glucose detection

Herein, the Cu₂O yolk-shell nanospheres, nanocubes and microcubes were successfully prepared by a simple seed-medium process. The formation of the Cu₂O yolk-shell nanospheres can be attributed to the self-assembly process caused by the introduction of the seed medium. The formation mechanism of our obtained Cu₂O yolk-shell nanospheres and the dependence of Cu₂O morphology on different surfactants have been studied. The obtained samples were applied in the field of non-enzymatic glucose detection. The electrochemical response characteristics of the modified electrodes toward glucose were investigated by cyclic voltammetry (CV) and chronoamperometry (CA). The electrode modified with C-Cu₂O (obtained by using CTAB as surfactant) shared the highest sensitivity of 3123 μAmM^-1 cm^-2, whereas, the electrode modified with S-Cu₂O (obtained by using SDBS as surfactant) exhibited the lowest LOD of 0.87 μM and the widest linear range of 0.05-10.65 mM. All obtained sensors showed fast response to the addition of glucose. The obtained electrodes showed better responses to glucose than other coexisting interferences, indicating that the obtained electrodes had the acceptable selectivity to glucose. In addition, the stability for 5 consecutive weeks had also been studied and exhibited satisfactory results. The obtained electrode was also used to detect the glucose content in real serum. The acceptable selectivity, stability together with the excellent sensing ability in real serum make the obtained electrodes a potential for practical applications.

Multiwalled carbon nanotubes coated with cobalt(II) sulfide nanoparticles for electrochemical sensing of glucose via direct electron transfer to glucose oxidase

Multiwalled carbon nanotubes coated with cobalt(II) sulfide nanoparticles were prepared and used for immobilization of glucose oxidase (GOx) to obtain an electrochemical glucose biosensor. The nanocomposite was synthesized through an in-situ hydrothermal method and characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and electrochemical impedance spectroscopy. The results show that the nanocomposite possesses a large specific surface area and apparently enhances the direct electron transfer between GOx and the surface of the electrode, best at a potential near -0.43 V (vs. SCE). The immobilized GOx retains its good bioactivity even at a high surface coverage of 30 pmol cm^-2. Under the optimum conditions. The biosensor exhibits a wide linear range (from 8 μM to 1.5 mM), a high sensitivity (15 mA M ^-1 cm^-2), and a 5 μM detection limit (at S/N = 3). The sensor is selective, acceptably repeatable, specific and stable. Graphical abstractMultiwalled carbon nanotubes coated with cobalt(II) sulfide nanoparticles (CoS-MWCNTs) were synthesized through in situ hydrothermal method for the construction of a sensitive electrochemical glucose biosensor.

Functional nanomaterials with unique enzyme-like characteristics for sensing applications

We highlight the recent developments in functional nanomaterials with unique enzyme-like characteristics for sensing applications.