Luminescent carbon dots quantum dots and gold nanoclusters as sensors.

Ultra-small nanoparticles, including quantum dots, gold nanoclusters (AuNCs) and carbon dots (CDs), have emerged as a promising class of fluorescent material because of their molecular-like properties and widespread applications in sensing and imaging. However, the fluorescence properties of ultra-small gold nanoparticles (, AuNCs) and CDs are more complicated and well distinguished from conventional quantum dots or organic dye molecules. At this frontier, we highlight recent developments in the fundamental understanding of the fluorescence emission mechanism of these ultra-small nanoparticles.

Dopamine-induced photoluminescence quenching of bovine serum albumin-capped manganese-doped zinc sulphide quantum dots.

The direct detection of dopamine (DA) in human body fluids is a great challenge for medical diagnostics of neurological disorders like Parkinson's disease, Alzheimer's disease, senile dementia, and schizophrenia. In this work, a simple and turn off luminescence sensing of DA based on bovine serum albumin (BSA)-capped manganese-doped zinc sulphide quantum dots (Mn:ZnS/BSA QDs) is developed. The Mn:ZnS/BSA QDs were synthesized by a chemical co-precipitation method.

Amplified luminescence quenching effect upon binding of nitrogen doped carbon nanodots to transition metal ions.

There is a significant drive to identify a unified emission mechanism hidden behind carbon nanodots (CDs) to attain reliable control over their photoluminescence properties. This issue is addressed here by investigating the fluorescence response of citric acid and urea-based nitrogen doped carbon nanodots (NCDs) towards transition metal ions in solutions of different polarities/viscosities/hydrogen bonding strengths. The photoluminescence from NCDs upon excitation at 400 nm is quenched by metal ions such as chromium(vi), ruthenium(iii) and iron(iii) in two different polar solvents, protic water and aprotic dimethylsulphoxide (DMSO).

Reversible fluorescence modulation of BSA stabilised copper nanoclusters for the selective detection of protamine and heparin.

Protamine and heparin are the most important polyionic drugs used during surgeries and extracorporeal therapies. In this article, a selective and sensitive fluorescence method for the detection of both protamine and heparin was developed by using bovine serum albumin stabilised copper nanoclusters. Blue emitting fluorescent copper nanoclusters were synthesized in aqueous solution using bovine serum albumin as a capping agent and a reducing agent.

Fluorometric determination of morphine via its effect on the quenching of fluorescein by gold nanoparticles through a surface energy transfer process.

A method is described for sensitive and selective fluorometric determination of morphine. It is based on the effect of morphine on quenching of the fluorescence of fluorescein by gold nanoparticles (AuNPs) via surface energy transfer. When fluorescein is added to solutions of colloidal AuNPs, its fluorescence becomes quenched due to nanometal surface energy transfer (NSET) because the absorption of AuNPs strongly overlaps the emission spectrum of fluorescein.

Fluorescence turn on detection of bilirubin using Fe (III) modulated BSA stabilized copper nanocluster; A mechanistic perception.

Hyperbilirubinemia is the condition when bilirubin exceeds normal concentration in body (19.80 mg/mL in newborns and 1.19 × 10 mg/mL in adults).

S,N-doped carbon dots as a fluorescent probe for bilirubin.

Carbon dots doped with sulfur and nitrogen (S,N-CDs) were utilised to design a paper-stripe based fluorescent probe for the detection of bilirubin. The S,N-CDs were synthesized through a microwave assisted route by using citric acid as carbon source and L-cysteine as a source of nitrogen and sulfur. The S,N-CDs exhibit bright blue fluorescence emission with a peak at 452 nm.

Blue emitting copper nanoclusters as colorimetric and fluorescent probe for the selective detection of bilirubin.

Hurdles to develop point of care diagnostic methods restrict the translation of progress in the health care sector from bench side to bedside. In this article a simple, cost effective fluorescent as well as colorimetric nanosensor was developed for the early and easy detection of hyperbilirubinemia. A stable, water soluble bovine serum albumin stabilised copper nanocluster (BSA CuNC) was used as the fluorescent probe which exhibited strong blue emission (404nm) upon 330nm excitation.

Surface Engineered Ho Incorporated Fluorescent Dye-Doped Bifunctional Silica Nanoparticles for Receptor Targeted Fluorescence Imaging and Potential Magnetic Resonance Imaging.

The authors report Ho ion incorporated and fluorescent dye-doped silica nanoparticles which are engineered to enable the imaging modalities of receptor targeted fluorescence imaging (FI) and magnetic resonance imaging (MRI). The silica nanoparticles synthesized through a modified Stöber method is luminomagnetic by virtue of the luminescence of organic dye fluorophore (FITC) and magnetism of Ho. The doping concentration of Ho is estimated by inductively coupled plasma mass spectrometry (ICP-MS) as 0.