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A fluorescent probe Y((1,1'-([1,1'-biphenyl]-4,4'-diylbis(3-(2-hydroxyphenyl)-4,5-dihydro-1H-pyrazole-5,1-diyl)) bis(ethan-1-one))) was designed and synthesized, which could be used to Cu2+ and Fe3+ sensors. Through the study of optical properties, the probe Y shows good selectivity and sensitivity to Cu2+ and Fe3+ in aqueous tetrahydrofuran solution [10.0 mM HEPES, pH 7.4, THF-H2O = 9:1(v/v)] with has excellent anti-interference performance, and its detection limits were 0.931 uΜ for Cu2+ and 0.401uΜ for Fe3+. The coordination mechanism of probe Y with Cu2+ and Fe3+ was speculated and verified at DFT level and HRNM. By Hela cytotoxicity and imaging tests, probe Y not only has good biocompatibility, but also can be used for sensing Cu2+ in cells. [ABSTRACT FROM AUTHOR]

A photo-induced electron transfer cationic fluorescence probe L1 based on pyrene-naphthol system was designed to detect the change of Cu2+ with fluorescence. The probe L1 was found to selectively recognize Cu2+ in aqueous ethanol solution [10.0 mmol/L HEPES, pH 7.4, EtOH–H2O = 1:1 (v/v)] without interference from other coexisting metal ions. The response of the sensor to Cu2+ is transient and reversible, and anions generally have no impact on the selectivity of Cu2+. Probe L1 forms complex with Cu2+ in 1:1 ratio as supported by Job's plot analysis. The binding constants of Cu2+ was calculated to be 6.322 × 104 L/mol using a nonlinear curve-fitting method. The detection limit of Cu2+ was determined to be 1.620 × 10–7 mol/L. The energy gap between HOMO and LUMO in L1 and L1–Cu2+ was calculated by density functional theory as 3.76 eV and 2.71 eV, respectively. In addition, the probe L1 has extremely low cytotoxicity and can be used for living cell imaging studies. [ABSTRACT FROM AUTHOR]

Two fluorescent probes, Y1-2 were synthesized from 2-acetonaphthone, 4-acetylbiphenyl, and phenyl hydrazine by Vilsmeier-Haack reaction and Knoevenagel condensation. Their recognition efficacies for N2H4 were tested by UV–visible absorption spectroscopy and fluorescence emission spectroscopy. The recognition mechanism were studies by density-functional theory calculations, and the effect of pH on N2H4 recognition was also studied. The results showed that the probe Y1-2 has high selectivity and a low detection limit for N2H4, and the recognition of N2H4 can be accomplished at physiological pH. The probes have had obvious aggregation-induced luminescence effect, large Stokes shift, high sensitivity, and can be successfully applied to live cell imaging. [ABSTRACT FROM AUTHOR]

Two novel coumarin-based pyrazoline derivatives have been designed and synthesized as organogel factors. Organogelators Z 1–2 both have gelation behavior in alcohol solution and DMSO. Gel- tert -butanol Z 1–2 (CGC = 1.84%, 1.41%) fluoresce blue and yellow-green under ultraviolet irradiation, respectively. Z 1–2 both exhibit selectivity for response to Fe3+ in THF-deionized aqueous (V: V = 9:1) solution, meanwhile display high sensitivity. Notably, introducing diethylamino at 7-position the coumarin unit increases the detection line range in Z 2. Furthermore, Z 2 not only has a good biocompatibility in living cells but also the sensing behavior of Fe3+ in the cell nucleus. The coordination mechanism of gelators Z 1–2 and Fe3+ were performed at the DFT level. [Display omitted] • Two novel coumarin-based pyrazoline organogelators Z 1–2 have designed and synthesized. • The Z 1–2 can both form fluoresce organogels in tert-butanol (CGC=1.84%, 1.41%). • The Z 1–2 can both response to Fe3+ in aqueous solution and organogels with selectivity and sensitivity. • The Z 2 can detect Fe3+ in living cells. [ABSTRACT FROM AUTHOR]

Herein, a novel ferrocenyl pyrazoline–based organic gelator (Z) was synthesised and studied. Adding Z in various solvents could form stable organic gels, the state of which could be reversibly converted to the solution form from the gel form by heating or cooling. X-ray diffraction, Fourier-transform infrared spectroscopy and scanning electron microscopy revealed that intermolecular hydrogen bonding, π-π stacking and van der Waals interaction are the key to form organogels via the self-assembly of Z. The optical properties and fluorescence spectra of the compound were studied using ultraviolet–visible spectrophotometry. We found that the fluorescence of Z is highly selective and responsive to different metal ions, including Cu2+. Z was further used for intracellular imaging of living BHK-21 cells, showing excellent bioactivity and thereby, indicating its potential in broad applications. In addition, Z can respond to radiation, heating and vibration, thus giving the organic gel more stimulation. [ABSTRACT FROM AUTHOR]

A new chromene pyrazoline derivatives fluorescent probe L was designed and synthesized. The probe L appears in a 55-fold fluorescence enhancement after 5 equiv. Zn 2+ was added, and it also exhibits high sensitivity and selectivity for response to Zn 2+ in ethanol-water (V:V = 1:1) solution through “OFF-ON” type process and a possible photoinduced electron transfer (PET). Notably, the probe L distinguishes between Zn 2+ and Cd 2+ . The association constant was considered as 2.38 × 10 3  M −1 via fluorescence titration experiments. The probe L-Zn 2+ complex forms a 1:1 binding stoichiometry which was discussed by Job’s plot. The probe is very highly sensitive with fluorometric detection limit of 1.603 × 10 −10  M. It also shows good reversibility upon addition of EDTA. Furthermore, the viability of L to Zn 2+ has practical application in live cell imaging. [ABSTRACT FROM AUTHOR]

A new pyrazoline-based probe D was designed and synthesized, which can be used as a highly sensitive, selective and reversible recognizing fluorescent to detect Cu 2 + . The recognition properties of this compound was investigated by UV–vis absorption and fluorescence spectrophotometry. The results showed that the probe D forms a 1:1 complex with Cu 2 + and displayed a linear fluorescence response to Cu 2 + with a detection limit of 1.94 × 10 − 7 M. In addition, the probe have a good biocompatibility in living cells. [ABSTRACT FROM AUTHOR]

• The two novel fluorescent probes Z 1 and Z 2 based have been designed and synthesized base on pyrazole derivative to recognize hydrazine • The probe Z 1-2 have ICT characteristics with large Stokes shifts. • The probe Z 1-2 could be made into test paper strips for detection of hydrazine. • The probe Z 1-2 can be used in detection of N 2 H 4 in environmental soil samples and cell imaging. Here, the two novel fluorescent probes Z 1 and Z 2 have been designed and synthesized based on pyrazole derivative to recognize hydrazine, and the molecular structure was determined by 1H NMR, 13C NMR, and ESI-MS. The obtained probe molecules have AIE and ICT characteristics. Nuclear magnetic resonance analysis (NMR) and theoretical calculations were used to confirm the identification mechanism. Probes Z 1 and Z 2 have good selectivity, low detection limits (0.197 µM and 0.185 µM, respectively), and high sensitivity. Probes Z 1 and Z 2 have large Stokes shifts of 198 nm and 211 nm, respectively. The probes also could be made into test paper strips for the detection of hydrazine. Furthermore, the probes can be used in the detection of N 2 H 4 in environmental soil samples and cell imaging. The results showed that the synthetic probe had good biocompatibility. Cell imaging experiments were performed to apply probes to the detection of hydrazine hydrate in HeLa cells. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel pyrazoline fluorescent probe for detection of Fe3+was designed. • The probe A displays an excellent selective response to Fe3+ ion over other metal ions. • The probe A exhibit high absorption intensity and long emission wavelength. A novel coumarin-based pyrazoline fluorescent probe A was synthesized through a four-step reaction. The structure was characterized by 1H NMR(Nuclear magnetic resonance), 13C NMR and HR-ESI-MS(High resolution electrospray ionization mass spectrometry). The optical properties of the fluorescent probe was investigated by UV–vis absorption and fluorescence emission spectra. The results showed that the addition of Fe3+ makes the fluorescence emission spectra of A quenched and displayed a linear fluorescence response to Fe3+ with a detection limit of 1.01 × 10−7 M. It also shows good reversibility upon addition of EDTA(Ethylene diamine tetraacetic acid). The structure of the fluorescent probe was optimized by DFT(Density functional theory) calculations, and the binding mechanism between the fluorescent probe and the recognition ion was explained. Moreover, the probe also has practical application in cell imaging. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel pyrazoline fluorescent probe 1 was synthesized. • It can be used to detect Zn2+/ Cd2+ with high sensitivity and high selectivity. • It has good fluorescence reversibility. • It can be applied to fluorescent Zn2+/ Cd2+ imaging in living cells. A novel multi-response pyrazoline-based fluorescent probe 1 was designed and synthesized with a very simple molecular structure, which exhibited high sensitivity for detecting Zn2+ and Cd2+ in ethanol aqueous solution state based on the dissuasion of intramolecular charge transfer (ICT) and chelation-enhanced fluorescence (CHEF) effect. The binding modes of the complexes were determined to have 1:1 complexation stoichiometry and the binding constants were calculated to be 1.284 × 104 M−1 for Zn2+ and 4.313 × 103 M−1 for Cd2+ using the nonlinear curve-fitting method. Zn2+ and Cd2+ sensor have high anti-interference ability. Under optimal conditions, the detection limits were determined to be 0.9274 μM for Zn2+ and 0.8158 μM for Cd2+. Notably, the probe was found to have good biological compatibility and was employed to detect Zn2+/ Cd2+ in living Hela cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel pyrazoline fluorescent probe N was synthesized. • It can be used to detect Cu2+ with high sensitivity and high selectivity. • It can be applied to fluorescent Cu2+ imaging in living cells. • The color of probe N changed with Cu2+ by naked-eye. In this study, a new pyrazoline derivate (1-acetyl-3- (2-hydroxy-1-naphthyl)-5-(2-phenyl-2H-chromene)-2-pyrazoline, N) is described as fluorescent probe for fluorometric detection of Cu2+. This fluorescence of probe has a high selectivity only toward Cu2+ ion in the other metal ions. It is remarkably observed that the fluorescence intensity of N decreased in the presence of Cu2+ ions with a strong capability to resist perturbations. The Limit of detection (LOD) value is calculated as 8.85 × 10−7 M for Cu2+ while the complexation constant is calculated as 3.14 × 105 M−2 via fluorescence measurements. The interaction between of N and Cu2+ is reversible after adding PPi. The optimized calculation of the probe for Cu2+ is confirmed by TD-DFT calculations. N-Cu2+ is successfully applied in the intracellular imaging in living PK-21 cells that will have a great chance for wide application. [ABSTRACT FROM AUTHOR]