Three-dimensional Fe3O4-graphene macroscopic composites for arsenic and arsenate removal.

3D graphene macroscopic gel synthesized via self-assembly of GO nanosheets under basic conditions at low temperature is modified with polydopamine and Fe3O4 nanoparticles. The modification of polydopamine can not only strengthen the 3D graphene-based macroscopic architecture but also enhance the loadage and binding ability of Fe3O4 nanoparticles. The synthesized 3D Fe3O4-graphene macroscopic composites are characterized by SEM, XRD, XPS, BET, Raman and magnetic property and used as a versatile adsorbent for sub-ppm concentration of As(III) and As(V) removal from aqueous solutions.

Mussel-inspired polydopamine coated mesoporous silica nanoparticles as pH-sensitive nanocarriers for controlled release.

A novel pH-sensitive controlled release system is proposed by using mussel-inspired polydopamine (PDA) coated mesoporous silica nanoparticles (MSNs) as nanocarriers. MSNs with a large pore diameter are synthesized by using 1,3,5-trimethylbenzene as a pore-expanding agent and are modified with a PDA coating by virtue of oxidative self-polymerization of dopamine in neutral pH. PDA coated MSNs are characterized by FTIR, TEM, N₂ adsorption and XPS techniques.

A pH-responsive controlled release system using layered double hydroxide (LDH)-capped mesoporous silica nanoparticles.

A pH-responsive controlled release system is proposed using acid-decomposable layered double hydroxides (LDHs) as inorganic nanovalves by virtue of the electrostatic adsorption of LDH nanosheets on the surface of mesoporous silica nanoparticles (MSNs). Guest molecules (Ru(bpy)Cl in this case) are loaded and encapsulated in a neutral environment. The dissolution of the LDH coatings in an acidic environment triggers the release of the guest molecules from the MSNs.

A G-quadruplex based label-free fluorescent biosensor for lead ion.

Many Pb(2+) biosensors based on Pb(2+)-specific RNA-cleaving DNAzyme have been developed in the past years. However, many of them have limited practical use because of high cost (e.g.

A sensitive and selective DNAzyme-based flow cytometric method for detecting Pb2+ ions.

A sensitive and selective Pb(2+) sensor based on GR-5 DNAzyme has been developed by a flow cytometric method.