Design of Ratiometric Emission Probe with Visible Light Excitation for Determination of Ca²⁺ in Living Cells

Abstract

An organic salt as a fluorescent probe based on intramolecular charge transfer for Ca(2+) determination is developed. Ca(2+) can be detected by ratiometric emission at 490 and 594 nm with an excitation wavelength of 405 nm. This probe is highly selective for Ca(2+) over other divalent metal cations and displays a large Stokes shift of 189 nm that can avoid interference of the excitation light beam and autofluorescence of biological samples. The dissociation constant for Ca(2+) is 2.25 ± 0.47 μM and pertinent to Ca(2+) detection in cellular resting and dynamic states. The probe demonstrates its application in monitoring Ca(2+) in living cells under confocal microscopic imaging.

Luminescent gold nanocluster-based sensing platform for accurate H2S detection in vitro and in vivo with improved anti-interference

“…Except K + and Na + , other metal ions with high concentrations showed intense effects on the response of the probe for the detection of H 2 S due to the strong affinity between the metals and sulfide ions. However, the concentrations of these free metal ions are below 10 −7 M in cells according to previous reports 59 , 60 , 61 , 62 , 63 . The luminescence ratio changes with these metal ions (10 −7 M) being added demonstrated that these metal ions with low concentrations showed only small effects on the detection of H 2 S. The sensing properties of the probe to H 2 S were investigated in the presence of different proteins.…”

Where is it and how much? Mapping and quantifying elements in single cells

“…The dye showed its application in monitoring Ca 2+ in live cells by confocal microscopy. 33 The same principles employed in the design of Ca 2+ probes were applied for the synthesis of the first fluorescent Mg 2+ dye: APTRA (o-aminophenol-N,N,O-triacetic acid). 34 The evolution of the APTRA molecule is represented by the commercial dye FURAPTRA (mag-fura-2), which carries a modified structure around the furan ring.…”

Electrochemistry/Photoelectrochemistry-Based Immunosensing and Aptasensing of Carcinoembryonic Antigen

“…By the comparison of two analytical methods, an overlapped linear concentration range (from 500 fg mL −1 to 5.0 ng mL −1 ) was gained, which proved the reliability of this immunosensor and opened an alternative avenue for quantitative monitoring of other tumor markers. Enlightened by the ratiometric fluorescence and electrochemiluminescence techniques [48][49][50], the construction of dual-potential ratiometric electrochemical Enlightened by the ratiometric fluorescence and electrochemiluminescence techniques [48][49][50], the construction of dual-potential ratiometric electrochemical biosensors based on the self-calibration of two different current signals is feasible for reducing a number of errors [51,52]. In this communication, using carboxyl-Au nanoparticle-decorated mesoporous CeO 2 nanoparticles (Au-CeO 2 )-supported toluidine blue (TB) and Au nanoparticle-functionalized Cu 2 S-CuS/graphene (Au-Cu 2 S-CuS/graphene) nanocomposites as signal label and transducing elements, respectively, Wei et al proposed a novel dual-potential ratiometric electrochemical biosensor to sensitively monitor CEA levels [53].…”