β-Ni(OH) nanosheets: an effective sensing platform for constructing nucleic acid-based optical sensors.

In this study, beta nickel hydroxide (β-Ni(OH)) nanosheets, one of the transition metal oxyhydroxides with two dimensional (2D) structures, were explored as a new fluorescent biosensor platform and applied in constructing optical sensors for bioanalysis. It was found that β-Ni(OH) nanosheets displayed a high fluorescence quenching ability and different affinity toward single- versus double-stranded DNA. Moreover, the absorption properties of β-Ni(OH) nanosheets can be well controlled by changing cations, solution pH and the length of DNA.

An enhanced electrochemical platform based on graphene oxide and multi-walled carbon nanotubes nanocomposite for sensitive determination of Sunset Yellow and Tartrazine.

A novel electrochemical platform was designed for the simultaneous determination of Sunset Yellow (SY) and Tartrazine (TT), synthetic food dyes, by combining the signal amplification properties of graphene oxide (GO) and the excellent electronic and antifouling properties of multi-walled carbon nanotubes (MWCNTs). Stable dispersion of GO/MWCNTs composite was produced by sonication mixing. Compared with glassy carbon, MWCNTs and GO electrodes, GO/MWCNTs electrode exhibited strong enhancement effect and greatly increased the oxidation signal of SY and TT.

DNA-templated synthesis of PtAu bimetallic nanoparticle/graphene nanocomposites and their application in glucose biosensor.

In this paper, single-stranded DNA (ss-DNA) is demonstrated to functionalize graphene (GR) and to further guide the growth of PtAu bimetallic nanoparticles (PtAuNPs) on GR with high densities and dispersion. The obtained nanocomposites (PtAuNPs/ss-DNA/GR) were characterized by transmission electron microscopy (TEM), energy-dispersive X-ray spectrometer (EDS), and electrochemical techniques. Then, an enzyme nanoassembly was prepared by self-assembling glucose oxidase (GOD) on PtAuNP/ss-DNA/GR nanocomposites (GOD/PtAuNPs/ss-DNA/GR).

Supramolecular assembly of enzyme on functionalized graphene for electrochemical biosensing.

The self-assembly of cyclodextrin (CD) functionalized graphene (GR) and adamantane-modified horseradish peroxidase (HRP-ADA) by host-guest supramolecular interaction into novel nanostructures in aqueous solution is reported in the present study. Electrochemical impedance spectroscopy and cyclic voltammetry were applied to characterize the self-assembly process and study the electrochemical behaviors of the immobilized proteins. UV-vis spectra indicated that the native structure of HRP was maintained after the assembly, implying good biocompatibility of CD-functionalized GR (CD-GR).