Urchin-like PtNPs@Bi 2 S 3 : synthesis and application in electrochemical biosensor.

Efficient urchin-like Pt nanoparticles@Bi 2 S 3 (PtNPs@Bi 2 S 3 ) composite materials were prepared by a composite soft template synthesis of urchin-like Bi 2 S 3 and then the microwave-assisted growth of PtNPs onto the Bi 2 S 3 nanostructure. For the first time, an accurate electrochemical glucose biosensor was fabricated via immobilizing glucose oxidase (GOx) on PtNPs@Bi 2 S 3 . The PtNPs@Bi 2 S 3 composite was investigated via scanning electron microscopy, electrochemical impedance spectroscopy, Fourier transform infrared spectroscopy, and cyclic voltammetry. The PtNPs@Bi 2 S 3 composite provides a large surface area to load a large number of enzyme molecules, which maintains the biological activity. PtNPs loaded on Bi 2 S 3 enhanced the conductivity and improved the direct electron transfer of the proposed biosensor with the synergistic effect. The fabricated electrochemical biosensor possesses high sensitivity, and a wide linear range from 0.003 mM to 0.1 mM and 0.1 mM to 1.9 mM. Moreover, the biosensor has outstanding stability, superior selectivity and good repeatability, which can be utilized to monitor the glucose level in practical human serum. The PtNPs@Bi 2 S 3 composite supplies a special matrix for immobilizing proteins and potential for establishing other effective biosensors.