Multiple fluorescent chemical sensing and imaging.

Optical sensors, unlike most others, enable multiple sensing of (bio)chemical species by making use of probes whose signals can be differentiated by spectral and/or temporal resolution. Multiple sensors are of substantial interest for continuous monitoring of chemical parameters in complex samples such as blood, bioreactor fluids, in the chemical industry, aerodynamic research, and when monitoring food quality control, to mention typical examples. Moreover, such sensors enable non-invasive, non-toxic and online detection.

Red- and green-emitting iridium(III) complexes for a dual barometric and temperature-sensitive paint.

A new dual luminescent sensitive paint for barometric pressure and temperature (T) is presented. The green-emitting iridium(III) complex [Ir(ppy)(2)(carbac)] (ppy=2-phenylpyridine; carbac=1-(9H-carbazol-9-yl)-5,5-dimethylhexane-2,4-dione) was applied as a novel probe for T along with the red-emitting complex [Ir(btpy)(3)], (btpy=2-(benzo[b]thiophene-2-yl)pyridine) which functions as a barometric (in fact oxygen-sensitive) probe. Both iridium complexes were dissolved in different polymer materials to achieve optimal responses.

pH sensor based on upconverting luminescent lanthanide nanorods.

The pH sensor exploits the phenomenon of upconversion luminescence and is based on a hydrogel matrix containing (a) nanorods of the NaYF(4):Er,Yb type that can be excited with 980-nm laser light to give a green and red (dual) emission, and (b) a longwave absorbing pH probe that causes a pH-dependent inner filter effect.

Method for simultaneous luminescence sensing of two species using optical probes of different decay time, and its application to an enzymatic reaction at varying temperature.

Chemical sensing, imaging and microscopy based on the use of fluorescent probes has so far been limited almost exclusively to the detection of a single parameter at a time. We present a scheme that can overcome this limitation by enabling optical sensing of two parameter simultaneously and even at identical excitation and emission wavelengths of two probes provided (a) their decay times are different enough to enable two time windows to be recorded, and (b) the emission of the shorter-lived probe decays to below the detectable limit while that of the other still can be measured. We refer to this new scheme as the dual lifetime determination (DLD) method and show that it can be widely varied by appropriate choice of probes and experimental settings.