Photophysical approaches to responsive optical probes

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Responsive optical probes play a vital role in following and understanding biological events. In this review, we focus on the use of lanthanide complexes as molecular probes, as they offer many advantages in imaging and assays, particularly when used in time-gated protocols. We describe systems that illustrate the key photophysical approaches to achieving analyte-dependent signal modulation. In summary, this signal modulation can be achieved through changes either in the coordination sphere of the lanthanide or in the pathway of sensitized emission. In conclusion, we describe the main challenges to be overcome in the field of responsive probes, mainly the effective determination of concentrations in vivo and the development of probes with temporal responses adequate to follow fast processes.

Related collections

Most cited references 50

Record: found
Abstract: found
Article: not found

New calcium indicators and buffers with high selectivity against magnesium and protons: design, synthesis, and properties of prototype structures.

R Tsien (1980)

A new family of high-affinity buffers and optical indicators for Ca2+ is rationally designed and synthesized. The parent compound is 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA), a relative of the well-known chelator EGTA [ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid] in which methylene links between oxygen and nitrogen are replaced by benzene rings. BAPTA and its derivatives share the high (greater than 10(5)) selectivity for Ca2+ over Mg2+ of EGTA but are very much less affected by pH changes and are faster at taking up and releasing Ca2+. The affinity of the parent compound for Ca2+ (dissociation constant 1.1 x 10(-7) M in 0.1 M KCl) may be strengthened or weakened by electron-releasing or -withdrawing substituents on the aromatic rings. The Ca2+ and Mg2+ affinities may further be altered by replacing the ether oxygens by heterocyclic nitrogen atoms. The compounds described are fluorescent Ca2+ indicators absorbing in the ultraviolet region; the very large spectral shifts observed on binding Ca2+ fit the prediction that complexation should hinder the conjugation of the nitrogen lone-pair electrons with the aromatic rings. Derivatives with quinoline nuclei are notable for their high sensitivity of fluorescent quantum yield to the binding of Ca2+ but not of Mg2+. Preliminary biological tests have so far revealed little or no binding to membranes or toxic effects following intracellular microinjection.

0 comments Cited 211 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Design of fluorescent materials for chemical sensing.

David N. Reinhoudt, Lourdes Basabe-Desmonts, Mercedes Crego-Calama (2007)

There is an enormous demand for chemical sensors for many areas and disciplines. High sensitivity and ease of operation are two main issues for sensor development. Fluorescence techniques can easily fulfill these requirements and therefore fluorescent-based sensors appear as one of the most promising candidates for chemical sensing. However, the development of sensors is not trivial; material science, molecular recognition and device implementation are some of the aspects that play a role in the design of sensors. The development of fluorescent sensing materials is increasingly captivating the attention of the scientists because its implementation as a truly sensory system is straightforward. This critical review shows the use of polymers, sol-gels, mesoporous materials, surfactant aggregates, quantum dots, and glass or gold surfaces, combined with different chemical approaches for the development of fluorescent sensing materials. Representative examples have been selected and they are commented here.