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A simple and unique dual-channel chemical probe (DH) was designed and synthesized, which not only realized sequential recognition of Cu2+ and CN− by colorimetric and fluorometric methods, but also realized fluorescence detection of CN−. When different cations (Co2+, Mg2+, Ni2+, Cd2+, Hg2+, Al3+, Ag+, Cu2+, Pb2+, Fe3+, Zn2+ and Ca2+) were added into the solution containing the probe molecule DH, only Cu2+ induced an observable change in the UV-vis and fluorescence spectra, indicating that the probe molecule can be applied for specific recognition of Cu2+. The anti-interference experiment of DH to Cu2+ showed that DH has good selectivity for detecting Cu2+, with a detection limit of 7.05 × 10−7 M. In particular, the fluorescence "ON–OFF–ON" process can be recycled by sequentially adding Cu2+ and EDTA, and the fluorescence intensity remained unchanged after ten times. This observation suggested that DH can achieve reversible highly sensitive response to Cu2+ and EDTA, and can be used as a hypersensitive logic gate for Cu2+ detection. More interestingly, when different anions (CH3COO−, SO32−, H2PO4−, ClO4−, NO3−, HSO4−, I−, Cl−, F−, Br−, N3− and CN−) were added into the solution containing DH and Cu2+, only CN− induced color change of the solution from red to yellowish green, and the fluorescence intensity greatly enhanced, indicating that DH-Cu2+ has a specific response to CN−. The anti-interference experiment showed that DH-Cu2+ has good selectivity for CN−, with a detection limit of 8.11 × 10−6 M. Moreover, the probe molecule DH can detect CN−, with a detection limit of 7.61 × 10−6 M. Experimental and theoretical methods were applied to deeply study the detection mechanism of DH, present great potential in practical application for ion test strips and HeLa cell imaging reagents. [ABSTRACT FROM AUTHOR]

A novel fluorescent chemosensor based on trimesoyl chloride–rhodamine (TR) was successfully synthesized. Rising chromogenic and fluorogenic spectral enhancements could be observed in trimesoyl chloride–rhodamine (TR) probes when Hg2+ and Fe3+ were added, respectively. TR has shown selectivity for Hg2+ and Fe3+ with high sensitivity due to metal ion complexation induced photophysical "turn-on" signaling responses. The detection limit towards Hg2+ was 2.46 × 10−8 M as determined by the 3σ method. At the same time, fluorogenic spectral enhancements were observed in TR, which exhibits a superior sensitive and selective recognition towards Fe3+ with 4.11 × 10−8 M of the detection limit. The test strips were used for colorimetric and simple detection towards Hg2+, which might finally enable the advancement of the Hg2+ sensor in the field of on-site detection. [ABSTRACT FROM AUTHOR]

A supramolecular sensor (APRA–G) was successfully constructed via host–guest interactions between a rhodamine hydrazone functionalized pillar[5]arene (APRA) and a bis-pyridinium derivative (G), which showed highly selective and sensitive detection of toxic Hg2+ through a dual-channel (colorimetric and fluorescent) model. The detection limits of fluorescence and UV-vis spectroscopy towards Hg2+ were 1.69 × 10−8 M and 4.07 × 10−7 M, respectively, which were calculated using the 3σ method. Interestingly, APRA–G could act as an excellent material for Hg2+ separation. Based on ICP (including inductively coupled plasma) data, the separation percentage of the supramolecular sensor (APRA–G) for mercury ions was up to 99.68%. [ABSTRACT FROM AUTHOR]

A novel approach for in situ generation of AgI quantum dots by the confinement of a pillar[5]arene‐based supramolecular polymer network has been successfully developed. The supramolecular polymer network (SPN‐QP) was constructed by using a bis‐8‐hydroxyquinoline‐modified pillar[5]arene derivative as a host (H‐QP) and a bis‐pyridinium‐modified decane as guest (G‐PD). The SPN‐QP shows ultrasensitive response for Ag+. The limit of detection is about 7.44×10−9 M..Interestingly, when I− was added to the SPN‐QP+Ag+ system, an unexpected strong warm‐white fluorescence emission was observed. After carefu investigation, we found that the strong warm‐white fluorescence emission could be attributed to the in situ formation of AgI quantum dots under the confinement of the supramolecular polymer network (SPN‐QP). Based on this approach, ultrasensitive detection of I− was realized. The limit of detection for I− is 4.40×10−9 M. This study provides a new way for the preparation of quantum dots under the confinement of supramolecular polymer network as well as ultrasensitive detection of ions by in situ formation of quantum dots. [ABSTRACT FROM AUTHOR]

Stimuli-response supramolecular fluorescent materials have received significant attention in recent years since they endow specific and unique properties to materials. Herein, a bi-acylhydrazone supramolecular gelator HT was successfully prepared by simple Schiff base reaction. Interestingly, the gelator HT could self-assemble into supramolecular gel HT-G in DMSO-H 2 O binary solutions via π-π stacking interactions. Simultaneously, gel HT-G showed specially selective and ultrasensitive sensing property for CN−. The limit of lowest detection of the gel for CN− is 0.50 nM. In addition, the thin films based on the HT-G and HT-G + CN− were also prepared, which could not only act as supramolecular fluorescent material but a convenient and efficient tool for detection CN−. A novel bis-acylhydrazone supramolecular gel (HT-G) was constructed, which could ultrasensitively detect CN− in aqueous medium. Image 1 • A novel bis-acylhydrazone supramolecular gel HT-G was designed and synthesized via π-π stacking interactions. • The supramolecular gel HT-G presented excellent single selectivity towards CN−. • The supramolecular gel HT-G shown ultrasensitive sensing ability for CN−. • The test thin film could serve as practical detection application of CN− in aqueous medium. [ABSTRACT FROM AUTHOR]

In this work, we designed and synthesized a phenazine derivative (PS) based fluorescent sensor which could detect mercury ion and silver ion in DMSO/H 2 O (1:9, v/v) solution. The ensemble based non-fluorescent PS-Ag+ complex could be used as a turn-off and on emission system for selective detection of Hg2+ through competitive coordination in aqueous solution. • PS self-assembled into a supramolecular sensor via π-π stacking. • A novel supramolecular sensor for highly sensitive detection • New chemosensor for selective fluorescent turn-on detection of Hg2+. • PS could be used for detection of Ag+ and Hg2+ in the wide pH range. In this work, we designed and synthesized a chromene-functionalized imidazophenazine-based fluorescent sensor (PS) which can detect mercury ions and silver ion in aqueous solution by different fluorescence behavior. When Hg2+ was added to the solution of PS , the fluorescent color of PS changed from yellow to green, and the emission peak was shifted from 543 nm to 511 nm. Upon the addition of Ag+, the fluorescence of PS was quenched. The detection limits of the PS for Hg2+ and Ag+ were calculated as 1.2 × 10−7 M and 3.6 × 10−8 M, respectively. In addition, the Ag+-coordinated non-fluorescent complex (PS-Ag+) could be used as new chemosensor for selective fluorescent turn-on detection of Hg2+ through competitive coordination in aqueous solution with a detection limit of 1.5 × 10−8 M. [ABSTRACT FROM AUTHOR]

In this work, we constructed a supramolecular gel (PN-G) by phenazine derivative, which can ultrasensitive detect cyanide (detection limit equals to 4.18 × 10−10 M). The decrease of fluorescent intensity displayed a linear relationship in the range of 0–0.4 equivalents of cyanide. And no significant fluorescence quenching was observed for all used interfering ions. The cyanide recognition mechanism of PN-G was verified by XRD, NMR, MS and SEM. With addition of cyanide to the supramolecular gel (PN-G), cyanide broken π-π stacking of PN-G , and then PN-G undergoes a nucleophilic addition reaction with CN−, resulting in fluorescence quenched. A supramolecular gel (PN-G) was constructed, which could ultrasensitively detect cyanide. Image 1 • Constructed a supramolecular gel by self-assembly. • A novel supramolecular gel for highly selective and sensitive detection of cyanide. • Taking advantage of a simple mechanism of nucleophilic addition reaction. [ABSTRACT FROM AUTHOR]

A reversible dual-channel chemosensor ( W ) based on double Schiff-base for ultrasensitive fluorescence detection of Cu 2+ in DMSO solution has been designed and synthesized. Upon the addition of Cu 2+ , the chemosensor W showed visible color changes (from yellow to colorless) and the fluorescence was immediately quenched. The fluorescence spectrum detection limit for Cu 2+ was 4.87 nM, which is much better than most reported fluorescent sensors for Cu 2+ . Interestingly, the sensing behavior was found to be reversible with addition of EDTA, which indicated that W not only could act as a nice candidate for Cu 2+ and EDTA controlled “ON-OFF-ON” fluorescence switch, but was utilized as an ultrasensitive IMPLICATION logic gate at the molecular level. More importantly, ion test strips based on W were fabricated, which could act as convenient and efficient test kits to detect Cu 2+ for “in-the-field” measurement. [ABSTRACT FROM AUTHOR]

A novel fluorescent chemosensor based on trimesoyl chloride–rhodamine (TR) was successfully synthesized. Rising chromogenic and fluorogenic spectral enhancements could be observed in trimesoyl chloride–rhodamine (TR) probes when Hg2+ and Fe3+ were added, respectively. TR has shown selectivity for Hg2+ and Fe3+ with high sensitivity due to metal ion complexation induced photophysical "turn-on" signaling responses. The detection limit towards Hg2+ was 2.46 × 10−8 M as determined by the 3σ method. At the same time, fluorogenic spectral enhancements were observed in TR, which exhibits a superior sensitive and selective recognition towards Fe3+ with 4.11 × 10−8 M of the detection limit. The test strips were used for colorimetric and simple detection towards Hg2+, which might finally enable the advancement of the Hg2+ sensor in the field of on-site detection. [ABSTRACT FROM AUTHOR]

A supramolecular sensor (APRA–G) was successfully constructed via host–guest interactions between a rhodamine hydrazone functionalized pillar[5]arene (APRA) and a bis-pyridinium derivative (G), which showed highly selective and sensitive detection of toxic Hg2+ through a dual-channel (colorimetric and fluorescent) model. The detection limits of fluorescence and UV-vis spectroscopy towards Hg2+ were 1.69 × 10−8 M and 4.07 × 10−7 M, respectively, which were calculated using the 3σ method. Interestingly, APRA–G could act as an excellent material for Hg2+ separation. Based on ICP (including inductively coupled plasma) data, the separation percentage of the supramolecular sensor (APRA–G) for mercury ions was up to 99.68%. [ABSTRACT FROM AUTHOR]

Here, we reacted 2,3-Diaminophenazine with salicylaldehyde to generate dye molecule 2-Hydroyphenyl-(1 H -imidazo[4,5-b]phenazine(P1). The crystal structure displayed that P1 and DMSO molecule formed 2D supramolecular layered structure through non-covalent weak interactions. More importantly, the dye molecule P1 had excellent selectivity and sensitivity to Fe3+ and Cu2+, and detection limits from fluorescence data were found to be 3.25×10-7 M and 1.25×10-7 M, respectively. The complex P1-Fe3+ can also further detect H 2 PO 4 -. In addition, P1-I- (I-=F- and AcO-) can be used as an excellent ligand for Ag+ removal. According to ICP data, the removal rate of Ag+ by dye molecules P1-I- reached 94.91% and 96.00%, respectively. [Display omitted] • Dye molecule P1 and DMSO form a 2D supramolecular layered structure through a variety of non-covalent weak interactions. • The dye molecule P1 can effectively detect Fe3+ and Cu2+, and the complex P1-Fe3+ can further detect H 2 PO 4 −. • P1-I- (I-=F- and AcO-) can effectively remove Ag+, and the removal rate reaches 94.91% and 96.00%. • P1 can quickly and easily detect Fe3+ and Cu2+, and can make a low cost, high efficiency detection kit for Fe3+ and Cu2+. Application of dye molecules to detect and remove heavy metal ions in a variety of complex systems often poses significant challenge. Here we have developed a fast, low-cost phenazine based dye 2-Hydroyphenyl-(1 H -imidazo[4,5-b]phenazine(P1) for fluorescence detecting Fe3+, Cu2+ and removing Ag+ from solution by colorimetry. The crystal structure e xhibited that P1 and DMSO molecules assemble into dimer through intermolecular hydrogen bonds. P1 can detect Fe3+ and Cu2+ by fluorescent change, the detection limit(LOD) of P1 for Fe3+ and Cu2+ were calculated as 3.25 × 10-7 M and 1.25 × 10-7 M, respectively. The complex P1-Fe3+ showed high selectivity and quick fluorescence turn on response for H 2 PO 4 -. In addition, P1-I - (I- =F- and AcO-)has a greatly brilliant to remove Ag+. The removal rates could be reached to 94.91% and 96.00%, respectively. [ABSTRACT FROM AUTHOR]

Detection of toluene (Tol) at a very low level in aqueous solution is significant in the chemical and industrial process. Herein, we were rationally employing a "synergistic effect" in the design of Tol sensor and synthesized a novel supramolecular fluorescent sensor (FB) based on a tetra-hydrazone-biphenol derivative. Interestingly, the sensor FB can selectively and sensitively detect Tol by distinguishing fluorescent change, and the detection limits (LOD) is 8.19 × 10−6 M. This Tol sensing process was achieved through the synergistic effect based on the collaboration of the tetra hydrazine and the hydroxyl groups. In addition, the sensing mechanism between FB and Tol was further investigated by experiments and density-functional theory (DFT) calculations. This work provides a feasible way to detect Tol by synergistic effect, and this recognition behavior makes FB a potential probe to detect Tol in environmental systems. [Display omitted] • A novel fluorescent sensor FB for detection toluene (Tol). • Tetra-hydrazone-biphenol structure provided a synergistic effect for sensing Tol. • The FB shows single selectivity and high sensitivity detection for Tol. • Theoretical calculations provided deeply understanding of the sensing mechanism. [ABSTRACT FROM AUTHOR]

Herein, by rationally introducing multi-interactions sites, a new rhodamine derivative BT was successfully designed and constructed. The BT can further self-assemble into a stable supramolecular organogel BTG and exhibits strong pink-white aggregation-induced emission (AIE). Interestingly, the BTG exhibits selective and ultrasensitive sensing property for Cu2+. The limit of lowest detection (LOD) of BTG for Cu2+ is approximately 0.829 nM. By adding Cu2+ into the BTG , a no fluorescence Cu2+ coordinated metallogel BTG-Cu formed. Due to the competitive coordination of Hg2+, the BTG-Cu exhibits promising sensing properties for Hg2+, such as high selectivity and ultra-sensitivity, fluorescence turn-on response, instant response to Hg2+ (<2s), and the limit of lowest detection (LOD = 0.567 nM). In addition, the xerogel of BTG and BTG-Cu were able to remove Cu2+ and Hg2+ from diluted aqueous solution at an adsorption rate of 99.02% and 99.46%, respectively. The thin films based on BTG and BTG-Cu were prepared, which can act as not only a supramolecular fluorescent material but a simple and efficient tool for detecting Cu2+ and Hg2+, respectively. [Display omitted] • Novel supramolecular organogel BTG with AIE effect was constructed. • The rhodamine-based sensor BTG shows ultrasensitivity for Cu2+. • The metallogel BTG-Cu can carry out ultrasensitive detection of Hg2+. • The BTG and BTG-Cu can adsorb and separate Cu2+ and Hg2+ from aqueous solution with nice adsorption property. • The film based on BTG-Cu act as a smart fluorescent display material. [ABSTRACT FROM AUTHOR]

A novel strategy, Th4+ tuned aggregation-induced emission, for sequential ultrasensitive detection and separation of Th4+ and Hg2+ was developed successfully. For demonstration this strategy, we designed and synthesized two tripodal gelators TH (tri-(isoniazid-4-yl)-functionalized trimesic acylhydrazine) and TA (tri-(pyridine-4-yl)-functionalized trimesic amide). The TH and TA could assemble into a stable supramolecular polymer hydrogel THTA-G in DMSO/H 2 O (3.3:6.7, v /v) binary-solution. The THTA-G does not show aggregation-induced emission (AIE) effect. However, after addition of Th4+ into the THTA-G , the obtained metallogel THTA-GTh shows strong green AIE effect, which indicated that Th4+ could tune the gel generation of AIE effect. Interestingly, the THTA-G could ultrasensitive fluorescently detect Th4+, and the corresponding metallogel THTA-GTh could ultrasensitively detect Hg2+. The detection limits of THTA-G and THTA-GTh for Th4+ and Hg2+ are 8.61 × 10−11 mol/L and 1.08 × 10−11 mol/L, respectively. Additionally, the xerogels of THTA-G and THTA-GTh could separate Th4+ and Hg2+ from aqueous solution with excellent ingestion capacity, and the THTA-G could be used as a writable smart light-emitting material. A novel strategy, Th4+ tuned aggregation-induced emission was developed successfully. Based on this strategy, sequential ultrasensitive detection and separation of Th4+ and Hg2+were achieved. Unlabelled Image • A novel strategy for sequential ultrasensitive detection of Th4+ and Hg2+. • Stable supramolecular polymer hydrogel THTA-G was constructed. • Th4+ could tune the hydrogel THTA-G generation of AIE effect. • The xerogels of THTA-G and THTA-GTh could separation of Th4+ and Hg2+. • THTA-G could act as a novel smart light-emitting material. [ABSTRACT FROM AUTHOR]

A novel supramolecular chemosensor (PNG) was successfully constructed by 5-(3-nitrophenyl)-furfural-functionalized Pillar[5]arene(PN) and bipyridine salt(G) via exo-wall π...π interactions. Interestingly, the chemosensor PNG could detect OH− and CO 2 with high selectivity, sensitivity and excellent recyclable properties. The fluorescent detection limits of PNG for OH− and CO 2 are 2.03 × 10−8 M and 9.1 × 10−8 M (2.22 ppm), respectively. The colorimetric detection limits for OH− and CO 2 are 3.78 × 10−8 M and 1.13 × 10−7 M (2.76 ppm), respectively. This study is simple and effective for OH− and CO 2 detection, and provides supramolecular fields with potential practical application in anion and gas detection. Image 1 • Synthesis of a novel arylfurfural functionalized pillar [5]arene (PN). • The PN and G could self-assemble to supramolecular chemosensor PNG by exo-wall π...π interactions. • The PNG shows excellent recyclable dual-channel detections for OH− and CO 2. • PNG -based sequential detection for OH− and CO 2 with high sensitivity and selectivity. [ABSTRACT FROM AUTHOR]

In this work, we designed and synthesized a ratiometric fluorescent sensor (POC) based phenazine derivative which can specifically detect hypochlorite (detection limit equals to 8.9 × 10−7 M) in DMSO/H 2 O (3:7, v/v) solution. With addition of hypochlorite to the solution of POC , hypochlorite broken π-π stacking of POC , and then oxidizes sulfur atoms in phenazine groups to sulfoxide, which resulted in the fluorescent color changed from blue to yellow. Job's plot showed that binding stoichiometry of POC with ClO− was 2:1. In addition, POC could be used to real-time detect hypochlorite in environment samples, and the naked eyes detection limit reached up to 7 × 10−5 M. In this work, we designed and synthesized a phenazine derivative (POC) based fluorescent sensor which could high selectivity detect hypochlorite in DMSO/H 2 O (3:7, v/v) solution. Image 1 • A novel fluorescent sensor for highly selective and sensitive detection of hypochlorite. • Taking advantage of a simple mechanism of oxidation reaction. • The test strips could conveniently and rapidly detect hypochlorite solutions. • POC could serve as a fluorescent sensor material for detecting the active ingredient in 84 disinfectant. [ABSTRACT FROM AUTHOR]