Functionalized carbon dots enable simultaneous bone crack detection and drug deposition.

Recently, carbon dots (CDs) have become one of the most sought nanomaterials for biological applications owing to their excellent fluorescence, chemical inertness and biocompatibility. This article depicts the generation of a fluorescent nano probe using CDs for viewing bone cracks and simultaneous drug delivery to the cracked or infected sites. Water soluble polyethylene glycol diamine capped CDs were conjugated with glutamic acid (GA), a calcium targeting ligand, and ciprofloxacin as an antibacterial model drug.

In vitro detection of calcium in bone by modified carbon dots.

This article depicts a simple and novel approach to locate calcium deposits in bone using modified carbon dots (CDs) through fluorescence imaging. Amino-functionalized CDs along with glutamic acid, a naturally-occurring ligand for calcium ions, were conjugated onto hyaluronic acid using EDC chemistry. The ability of the probe to recognise Ca ions was demonstrated using polymer strips doped with Ca ions and freshly collected bones.

Rapid and highly selective dipchecking for cyanide ions in aqueous media.

This article reports a simple dipping method for the detection of cyanide ions in water and biological samples, such as blood, using chitosan-gold nanoparticle (CH-Au NP) composite films prepared using CH-Au NP colloids. Here, gold nanoparticles were generated by heating (to ~80 °C) a solution of chitosan and gold chloride, where chitosan plays the dual role of reducing and stabilizing agent. The well-known chemistry of leaching of gold by cyanide is exploited here to detect cyanide ions.

Gold nanoparticles generated through "green route" bind Hg2+ with a concomitant blue shift in plasmon absorption peak.

We discuss here a quick, simple, economic and ecofriendly method through a completely green route for the selective detection of Hg(2+) in aqueous samples. Here we exploited the ability of chitosan to generate gold nanoparticles and subsequently to act as a stabilizer for the formed nanoparticles. When chitosan stabilized gold nanoparticles (CH-Au NPs) are interacted with Hg(2+) a blue shift for its localized surface plasmon resonance absorbance (LSPR) band is observed.

Naked eye detection of glucose in urine using glucose oxidase immobilized gold nanoparticles.

Colloidal gold is extensively used for molecular sensing because of the flexibilities it offers in terms of modification of the gold nanoparticle surface with a variety of functional groups using thiol chemistry. We describe a simple assay that allows the visual detection of glucose in aqueous samples and demonstrates its applicability by estimating glucose in urine. To enable the glucose detection, we functionalized the thiol capped gold nanoparticles with glucose oxidase, the enzyme specific to β-D glucose, using carbodiimide chemistry.