Highly Sensitive Amperometric Cholesterol Biosensor Based on Pt-Incorporated Fullerene-like ZnO Nanospheres

Abstract

A highly sensitive amperometric biosensor based on Pt-incorporated fullerene-like ZnO hybrid nanospheres has been investigated. Pt−ZnO nanospheres (PtZONS) with diameters in the range 50−200 nm have been successfully synthesized by electrodeposition on a glassy carbon electrode (GCE). The Pt nanoparticles in ZnO nanospheres have been identified with high-resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDS). The doped Pt nanoparticles demonstrate the abilities to electrocatalyze the oxidation of hydrogen peroxide and substantially raise the response current. The sensitivity of the PtZONS/GCE to hydrogen peroxide is 147.8 μA μM−1 cm−2, which is much higher than that of a conventional electrode. The PtZONS/GCE was functionalized with cholesterol oxidase (ChOx) by physical adsorption. The enzyme electrode exhibits a very high and reproducible sensitivity of 1886.4 mA M−1 cm−2 to cholesterol with a response time less than 5 s and a linear range from 0.5 to 15 μM. Furthermore, it has been revealed that the biosensor exhibits a good anti-interference ability and favorable stability over relatively long-term storage (more than 5 weeks). All these results strongly suggest that the PtZONS not only enhance the sensitivity to cholesterol but also help to eliminate the interference at low applied potential.

A Hydrogen Peroxide Biosensor Based on Direct Electrochemistry of Hemoglobin in Palladium Nanoparticles/Graphene–Chitosan Nanocomposite Film

“…GR is a single layer of carbon atoms with a hexagonal arrangement in a twodimensional lattice and is considered as "the thinnest material in our universe" [2]. The unique properties of GR include fast electron transportation, high thermal conductivity, excellent mechanical stiffness, and good biocompatibility [3], which result in promising applications in nanocomposites [4], solar cell [5], electromechanical resonators [6], and electrochemical sensors [7,8]. Moreover, GR is known to promote the direct electron transfer for the redox reaction of redox proteins, and the redox enzymes immobilized in graphene can retain their enzymatic activity [9][10][11].…”

Nanostructured metal oxide-based biosensors

“…A highly sensitive amperometric cholesterol biosensor based on platinum-incorporated fullerene-like ZnO hybrid nanospheres (50-200 nm) has been fabricated by electrodeposition of the nanospheres onto a GCE [32]. Th is biosensor exhibits improved sensitivity of 1.886 mA mM -1 cm -2 resulting in increased enzyme activity.…”

Recent Advances and Applications of Biosensors in Novel Technology

“…For instance, Iron-silica complexes have been utilized for immobilization of biomolecule owing to their improved biocompatibility [126]. ZnO and Pt can be used in the preparation of several classes of nanomaterials to enhance the efficiency of amperometric biosensors [127]. Attaching of NPs to the QCM results into the large surface area, variability in shape, and physicochemical malleability.…”