A highly Li+-selective glass optode based on fluorescence ratiometry

Abstract

This paper presents the preparation and characterization of a single-excitation, dual-emission ratiometric optical Li(+)-sensing device using a newly designed and synthesized highly Li(+)-selective fluoroionophore (KBL-01) carrying 14-crown-4 ether with tetramethyl and benzene blocking subunits as Li(+)-binding site and boron-dipyrromethene as fluorophore. The indicator dye was covalently immobilized on the surface of a porous glass support having a large internal surface area using a silane-coupling agent. The resulting Li(+)-selective glass optode shows dual fluorescence emission response in pseudo-serum at varying Li(+) concentrations, allowing ratiometric signal processing. The obtained signal is independent of the presence of possibly interfering cations (Na(+), K(+), Mg(2+) and Ca(2+)) and pH. The sensor response was found to be reversible within the Li(+) concentration range from 10(-4) to 10(-1) M, and showed good repeatability and light stability. The plots of the ratiometric signal versus the Li(+) concentrations in spiked real human serum go along with the response curve in pseudo-serum. These results indicate that the novel Li(+)-selective glass optode can be employed as a Li(+)-sensing device with high durability, sensitivity and accuracy for medical analyses.

A Fast-Response pH Optode Based on a Fluoroionophore Immobilized to a Mesoporous Silica Thin Film

“…[20][21][22] On the other hand, optodes using a hydrogel matrix as the substrate show response times that are below 30 s; however, indicator leaching is clearly observed under continuous flow operation. 23 Finally, the present response times are shorter than in the case of our previously presented sensors 15,24 using porous silica glass (thickness: 1 mm) as the substrate, which required 5 min or longer until equilibrium. Although it is not possible to separately state the degree of contribution of the two factors, it is obvious that both the mesoporous structure and the low film thickness contribute to the fast response times of the present optode.…”

An Aza‐12‐crown‐4 Ether‐Substituted Naphthalene Diimide Chemosensor for the Detection of Lithium Ion

“…The lithium cation (Li+) is one of the most abundant elements in aqueous environments and trace lithium i. e. 0.001–0.01 mM has been found in mammalian tissues, indicating it plays a role in biomolecular chemistry . Determination of trace amounts of Li + is an important as a small dosage of Li + (0.6–1.2 mM) is therapeutic to treat neurological diseases such as manic‐depressive illness, however, high a dose (>2 mM) is toxic and may be lethal ,,. Despite the importance of Li + in biology, there are only a few reports described for the selective detection of Li + ,.…”

“…Determination of trace amounts of Li + is an important as a small dosage of Li + (0.6–1.2 mM) is therapeutic to treat neurological diseases such as manic‐depressive illness, however, high a dose (>2 mM) is toxic and may be lethal ,,. Despite the importance of Li + in biology, there are only a few reports described for the selective detection of Li + ,. However, most of these methods suffer drawbacks, for example they either do not reach the required sensitivity for relevant biological concentrations, or do not display efficient selectivity over other metal cations such as the interfering Na+ ion.…”

Crowned spiropyran fluoroionophores with a carboxyl moiety for the selective detection of lithium ions

“…However, dosage is critical, as Li + is only effective within a narrow therapeutic window (0.6-1.2 mM); too lower a dose has no effect while too higher a dose (>2 mM) is toxic and lethal. [1][2][3]6 Despite the importance of Li + in biology there are only a few reports of fluorescence-based sensors for its detection. 1, [6][7][8][9][10][11] Most of these are either non-functional at relevant biological concentrations, or they do not display sufficient selectivity over other metal cations, in particular Na + .…”

“…[1][2][3]6 Despite the importance of Li + in biology there are only a few reports of fluorescence-based sensors for its detection. 1, [6][7][8][9][10][11] Most of these are either non-functional at relevant biological concentrations, or they do not display sufficient selectivity over other metal cations, in particular Na + . New biologically compatible fluorescent sensors and sensing devices that are selective for Li + are needed to provide a greater understanding of the biological role of Li + .…”