Colorimetric Fluorescent Sensor Research Articles

A nanoscaled lanthanide metal–organic framework as a colorimetric fluorescence sensor for dipicolinic acid based on modulating energy transfer

A visual colorimetric dipicolinic acid sensor was prepared by modulating the energy transfer process in the MOF.

A colorimetric fluorescent sensor for Cr3+ based on a novel diarylethene with a naphthalimide-rhodamine B group

Abstract A novel photochromic diarylethene with a 1,8-naphthalimide-rhodamine B unit has been synthesized and its photochemical properties were systematically studied. The diarylethene can effectively respond to the stimuli of light, proton, and specific metal ions. When triggered by Cr3+, strong fluorescence was observed at 603 nm due to the opening of the rhodamine B moiety, accompanied with a color change from colorless to purple. The result indicated that the diarylethene could act as a colorimetric fluorescent sensor for Cr3+ in acetonitrile. Moreover, a logic circuit was constructed by using the combinational stimuli of UV/vis and Cr3+/EDTA as inputs and the fluorescence intensity at 603 nm as output.

A new colorimetric fluorescent sensor for ratiometric detection of cyanide in solution, test strips, and in cells

A new high selective and sensitive fluorescent sensor for the detection of cyanide was developed based on the nucleophilic attack of CN− with a color change from purple to colourless. The chemosensor was used for fabrication of test strips that can detect cyanide in aqueous samples. The living animal fluorescence experiment demonstrated the practical value of the sensor in tracing the CN− in biological systems.

A novel BODIPY-based colorimetric and fluorometric dual-mode chemosensor for Hg2+ and Cu2+

A novel BODIPY-based colorimetric fluorescent sensor with bis[2-(phenylseleno)ethyl]amine as binding site (Se-1) for Hg2+ and Cu2+ has been developed. Se-1 shows high selectivity and sensitivity toward Hg2+ and Cu2+ over alkali and transition metal ions. Se-1shows a significant red-shift in the absorption spectra from 525 to 571nm for Hg2+ and 590nm for Cu2+, which induces color changes from pink to purple and blue. Upon excitation at 570nm, Se-1 upon interaction with Hg2+ ions displays a 5-fold fluorescence enhancement with a 2nm blue-shift, while Se-1 with Cu2+ exhibits a 13-fold fluorescence enhancement and red-shifts from 595 to 610nm. The binding mode of Se-1 with Hg2+ or Cu2+ has been investigated by Job's plot, ESI and 1H NMR experiments. The absorption and fluorescence of the Se-1–Hg2+ complex can be reversibly restored to that of the uncomplexed ligand by using EDTA or cysteine, however, the sensing processing of Se-1 in response to Cu2+ ions cannot.

A Schiff-Based Colorimetric Fluorescent Sensor with the Potential for Detection of Fluoride Ions

A simple Schiff-based colorimetric fluorescent receptor 1 was prepared. It exhibits a "turn-on-type" mode with high sensitivity in the presence of F(-). The change in color is very easily observed by the naked eye in the presence of F(-), whereas other anions do not induce such a change. Job plot indicated a 1:2 complexation stoichiometry between receptor 1 and F(-). The association constant for 1-F(-) in CH3CN was determined as 1.32*10(5)M(-2) by a Hill plot.

Highly selective colorimetric fluorescence sensor for Cu 2+: cation-induced ‘ switching on’ of fluorescence due to excited state internal charge transfer in the red/near-infrared region of emission spectra

A 1,8-naphthalimide-based colorimetric fluorescence perinone dye, receptor 1 is reported herein for the selective detection of Cu 2+ over the other heavy and transition metal ions. Receptor 1 shows a strong colorimetric change from orange to purple and a dramatic enhancement of fluorescence intensity due to cation-induced excited state internal charge transfer during the sensing event, that is, a dual optical response that would facilitate naked-eye detection of Cu 2+.

Highly Selective Colorimetric Fluorescent Sensor for Pb2+

Highly Selective Colorimetric Fluorescent Sensor for Pb²⁺

Highly Selective Colorimetric Fluorescent Sensor for Pb2+

AbstractPhenanthroline‐based colorimetric sensors 1 and 2 have been designed, synthesized, and compared with phenanthrene‐based receptor 3 for sensing of Pb2+ by color change. Receptor 1 imparts color change (from yellow to red) selectively with Pb2+ in acetonitrile/water (9:1) as well as in methanol/water (9:1) when in the presence of other metal ions studied (Li+, Na+, K+, Ca2+, Mg2+, Ba2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, and Mn2+ as their perchlorate salts). Receptor 1 also shows fluorescence enhancement upon addition of lead perchlorate in acetonitrile/water (9:1) solvent possibly due to the chelation enhanced fluorescence (CHEF) effect. However, the binding behavior of 2 with Pb2+ is found to be less effective compared to that of receptor 1.

A New Highly Selective, Ratiometric and Colorimetric Fluorescence Sensor for Cu2+ with a Remarkable Red Shift in Absorption and Emission Spectra Based on Internal Charge Transfer

A new 1,8-diaminonaphthalene based ratiometric and highly selective colorimetric "off-on" type of fluorescent probe, receptor 2 has been designed and synthesized that senses only Cu(2+) among the other heavy and transition metal ions examined on the basis of internal charge transfer (ICT). The visual sensitivity of the receptor 2 is remarkable, showing dual color changes from colorless (receptor) to purple followed by blue and a large red shift in emission upon Cu(2+) complexation.