Since the discovery of Quantum Dots (QDs) by Alexey I. Ekimov in 1981, the interest of researchers in that particular type of nanomaterials (NMs) with unique optical and electrical properties has been increasing year by year. Thus, since 2009, the number of scientific articles published on this topic has not been less than a thousand a year. The increasing use of QDs due to their biomedical, pharmaceutical, biological, photovoltaics or computing applications, as well as many other high-tech uses such as for displays and solid-state lighting (SSL), has given rise to a considerable number of studies about its potential toxicity. However, there are a really low number of reported studies on the detection and quantification of QDs, and these include ICP–MS and electrochemical analysis, which are the most common quantification techniques employed for this purpose. The knowledge of chemical phenomena occurring on the surface of QDs is crucial for understanding the interactions of QDs with species dissolved in the dispersion medium, while it paves the way for a widespread use of chemosensors to facilitate its detection. Keeping in mind both human health and environmental risks of QDs as well as the scarcity of analytical techniques and methodological approaches for their detection, the adaptation of existing techniques and methods used with other NMs appears necessary. In order to provide a multidisciplinary perspective on QD detection, this review focused on three interrelated key aspects of QDs: properties, surface chemistry and detection.

Neutral manganese, cobalt and nickel complexes of the pentadentate hydrazone 2,6-bis(1-salicyloylhydrazonoethyl)pyridine (H₄daps) have been prepared by means of electrochemical syntheses. They have been characterised by elemental analyses, IR spectroscopy, fast atom bombardment mass spectrometry (FAB) and magnetic susceptibility measurements. The molecular structures of [Mn(H₂daps)(py)₂] 1, [Co(H₂daps)(py)₂] 2, [Ni₂(H₂daps)₂]·CH₂Cl₂3, and [Ni₂(H₂daps)₂(py)₂]·CH₂Cl₂4 have been determined by X-ray diffraction. Depending on the nature of the metal ion, the dianionic [H₂daps]^2– ligand shows different co-ordination modes in these complexes: 1 and 2 are mononuclear with the metal atom in a pentagonal bipyramidal environment, 3 and 4 are binuclear with a helicate structure in which the nickel atoms attain octahedral co-ordination.

A mononuclear pentagonal bipyramidal Yb^III complex functions as a field-induced SIM luminescent thermometer.