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•A simple, multi-responsive and AIE active colorimetric and fluorescent probe ADC has been developed.•ADC showed high selectivity and sensitivity for rapid detection of Zn2+, Cu2+ and ...CN− with low detection limits.•The sensing mechanisms of the sensor ADC for Zn2+, Cu2+ and CN− were proposed.•ADC was used to detect and quantify Zn2+, Cu2+ and CN− ions in real water samples.•ADC was successfully applied to detect CN− in food samples.
A new simple and multi-responsive colorimetric and fluorescent probe with aggregation-induced emission (AIE) characteristic has been designed and synthesized. The probe 1-(((3-(tert-butyl)-2-hydroxy-5-methylbenzylidene)hydrazono)methyl)- naphthalen-2-ol ADC showed turn-on fluorescent response to zinc and cyanide ions (Zn2+ and CN−) and fluorescence quenching behavior to copper ion (Cu2+), which induces obvious naked-eye color changes, respectively. Probe ADC exhibited superb selectivity and swift sensitivity for simultaneous detection of Cu2+ and Zn2+ ions with excellent anti-interference capability over other common ions over a wide pH range (1–12). The probe ADC for Cu2+/Zn2+/CN− detection displayed fast response time (≤40 s) and low detection limits of 1.6 × 10−6, 1.3 × 10−8 and 8.1 × 10−7 M, respectively. The sensing mechanisms were confirmed by 1H NMR titration, FT-IR spectrum, Job’s plot analyses and TD-DFT theoretical calculations. Importantly, probe ADC could be used to detect and quantify Cu2+, Zn2+ and CN− in real water samples with a high precision and good accuracy. Moreover, the probe ADC was applied to the fast detection of CN− in bitter seeds, cassava, sprouting potato, revealing its great potential for practical applications in our daily life and health science. Importantly, this work provides a simple and effective approach with economically cheap and less complicated synthetic route for selective, sensitive and quantitative detection of multiple targets of Zn2+, Cu2+ and CN− ions in the environment and health systems.
A new highly selective and sensitive dual-mode sensor 3TD based on the conjugate of oligothiophene and barbituric acid moiety was developed for colorimetric and turn-on fluorescent detection of CN─. ...The sensor 3TD exhibited high specificity towards CN─ by interrupting its own ICT producing thereupon a large blue-shift in UV–Vis spectrum and remarkable “turn-on” fluorescence emission. The detection limit was 2.26 × 10─7 M, which is quite lower than the permissible level of CN─ in drinking water according to the WHO. The fluorescent detection of CN─ was well demonstrated by filter paper strips and silica coated TLC plates. Moreover, the sensor was also used to detect CN─ in environmental water and agro-products with satisfactory results. Most importantly, in terms of these advantages of colorimetric and turn-on fluorescent dual-mode, immediate response, excellent selectivity, high sensitivity, low cytotoxicity, and good biocompatibility, the sensor 3TD was successfully applied into CN− imaging in living cells, demonstrating its excellent value in practical application.
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•A new colorimetric naked-eye and turn-on fluorescent sensor 3TD was developed.•Sensor 3TD emerged strong response to CN− with rapid, selective, and sensitive characteristics.•Sensor 3TD could detect trace CN− in water, agro-products and test strips.•Sensor 3TD showed low cytotoxicity and was successfully applied to living cell imaging.
Developing low-cost and efficient sensors for rapid, selective and sensitive detection of the transition metal ions in environmental and food science is very important. In this study, a novel ...dual-functional fluorescent “turn-on” sensor 3TP based on oligothiophene-phenylamine Schiff base has been synthesized for discrimination and simultaneous detection of both Al3+ and Fe3+ ions with high selectivity and anti-interference over other metal ions. Sensor 3TP displayed a very fast fluorescence-enhanced response towards Al3+ and Fe3+ ions with low detection limits (0.177μM for Al3+ and 0.172μM for Fe3+) and wide pH response range (4.0–12.0). The Al3+/Fe3+ sensing mechanisms were investigated by fluorescence experiments, 1H NMR titrations, FT-IR and ESI-MS spectra. Importantly, sensor 3TP was served as an efficient solid material for the highly sensitive and selective detection of Fe3+ on TLC plates. Moreover, the sensor 3TP has been successfully used to detect trace Al3+ and Fe3+ in environment and food samples with satisfactory results and good recoveries, revealing a convenient, reliable and accurate method for Al3+ and Fe3+ analysis in real samples.
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•A new dual-functional fluorescent turn-on sensor 3TP for Al3+ and Fe3+ detection is reported.•The Al3+/Fe3+ detection exhibited high selective, excellent sensitive, fast response time and wide pH response range.•Test strips demonstrated sensor 3TP could be used as an optical solid-state sensor for Fe3+.•Sensor 3TP has been applied in environment and food samples analysis.
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•A new turn-on fluorescent sensor for dual detection of Fe3+ and Hg2+ was reported.•Sensor 3TB toward Fe3+/Hg2+ detection shows excellent performance characteristics.•The response ...time to Fe3+/Hg2+ ions is instataneous.•The sensor 3TB was successfully applied to detect Fe3+ in real water samples.
A novel fluorescent “turn-on” sensor 3TB for simultaneous sensing of Fe3+ and Hg2+ in aqueous media based on an oligothiophene Schiff base has been successfully synthesized and its fluorescent sensing properties were investigated in details. 3TB can selectively detect Fe3+ and Hg2+ by fluorescent spectroscopy among a series of various metal ions. Upon addition of Fe3+ or Hg2+ leads to a 44-fold or 19-fold fluorescence enhancement with a strong green fluorescence color. The binding stoichiometry ratio of 3TB–Fe3+ is recognized as 2:1 and 3TB–Hg2+ as 1:1 proved by the method of fluorescence measurements, FT-IR and 1H NMR, and the possible binding mode of the sensing system is also proposed. The sensor 3TB toward Fe3+ and Hg2+ was found to possess the excellent advantages of high association constants (1.34×106 and 8.99×104M−1), low detection limits (13.6 and 61.7nM), high selectivity and sensitivity, good anti-interference performance, instataneous response, wide pH response range (5.0–10.0), and outstanding fluorescence capacity to detect Fe3+ from water. These investigated results indicate that 3TB is an ideal sensor for Fe3+ and Hg2+ recognition. Moreover, the proposed sensor was successfully applied to effectively detect Fe3+ in real water samples.
A new oligothiophene functionalized Schiff base sensor 3TDC has been successfully designed and synthesized. Sensor 3TDC exhibited “naked-eye” colorimetric and selective “on-off” fluorescence response ...toward Cu2+ with high selectivity and sensitivity within a wide pH range. The binding ratio of the sensor 3TDC and Cu2+ was determined to be 1:1 through fluorescence titration, Job's plot, 1H NMR titration, FTIR and DFT studies. The detection limit is calculated to be as low as 2.81 × 10−8 M, which is much lower than the allowable level of Cu2+ in drinking water set by U.S. Environmental Protection Agency (~20 μM) and the World Health Organization (~30 μM). The binding constant (Ka) of Cu2+ to sensor 3TDC was found to be 2.52 × 104 M−1. Sensor 3TDC for Cu2+ detection exhibited fast fluorescence response within 30 s and high anti-interference performance. Moreover, sensor 3TDC could be used as an effective fluorescent sensor for detecting Cu2+ ions in various real water and food samples with good accuracy and high precision.
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•Novel oligothiophene Schiff-base as naked-eye colorimetric and fluorescent sensor 3TDC has been synthesized.•Sensor 3TDC displayed highly selective and sensitive fluorescence sensing for Cu2+ within wide pH range.•Sensor 3TDC for Cu2+ showed high anti-interference ability and instantaneous response time.•Sensor 3TDC has been applied to detect trace amounts of Cu2+ in real water and food samples.
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•A dual responsive colorimetric and fluorescent turn-on sensor DN for Fe3+ was synthesized.•Simple sensor DN towards Fe3+ exhibited excellent selectivity, high sensitivity and fast ...response (20 s).•The detection limit of Fe3+ was calculated as low as 0.178 μM.•Sensor DN was successfully used for detecting Fe3+ in water and food samples as well as test strips.
A new dual responsive colorimetric and fluorescent turn-on sensor DN for Fe3+ based on Schiff base derivative was designed and synthesized by one-step reaction. The sensor DN exhibited highly selective, sensitive and fast recognition toward Fe3+ with distinct color change by naked eyes in DMSO/H2O (1:1, v/v) solution over other competitive metal ions. The interaction of DN with Fe3+ caused a significant enhancement in emission intensity due to the restricted C = N isomerization and the suppression of highly efficient photoinduced electron transfer (PET) process. The sensing complex DN-Fe3+ was well-characterized to be 1:2 by the Job’s plot, 1H NMR titration, FTIR, HR ESI-MS analysis and DFT studies. The detection limit of DN for Fe3+ was as low as 0.178 μM, which displayed high sensitivity towards Fe3+. The sensor DN-based filter paper strips can be used to conveniently and effectively detect Fe3+ ions by the naked eyes. Importantly, the sensor DN was further used for detecting Fe3+ in real water and food samples with acceptable results and good recoveries.
A novel colorimetric and fluorometric dual-channel sensor DA with a favorable optical property and high specificity via a facile synthesis for Cu2+ was developed. DA showed a remarkably rapid ...response and high selectivity for Cu2+ over other metal ions with low detection limit of 15.1 nM. The sensing mechanism of DA for Cu2+ was based on the chelation-enhanced fluorescence quenching (CHEQ) mechanism, and further confirmed by optical measurements, FTIR, HRMS and DFT calculations. Importantly, DA for sensing Cu2+ possessed excellent sensing performances including colorimetric and fluorometric dual-mode detection, fast response, good reversibility, wide pH response range and strong anti-interference ability. Moreover, the DA could be not only applied to quantitatively detect Cu2+ in environmental water, food and drink samples, but also show highly colorimetric detection of Cu2+ on test strips and silica, indicating its possibility to be utilized as a convenient and low-cost sensor for environment and food monitoring.
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•A new colorimetric and fluorometric sensor DA was synthesized.•DA exhibits fast response and ultra sensitivity to Cu2+.•DA is successfully used for tracking Cu2+ in environmental water, food and drink samples.•DA served as an efficient optical solid-state sensor for highly colorimetric detection of Cu2+ on test strips and silica.
A simple, reversible, colorimetric and water-soluble fluorescent chemosensor ADA for the naked-eye detection of Cu2+ was developed. Sensor ADA showed high selectivity and sensitivity toward Cu2+ in ...~100% aqueous media over wide pH range. Sensor ADA exhibited a red-shift in the absorption spectra from 466 to 480nm that is accompanied by significant color change from light yellow to yellowish brown instantaneously. The Cu2+ recognition is based on the chelation–enhanced fluorescence quenching (CHEQ) effect of the paramagnetic nature. The lowest detection limit is determined to be 15.8nM, which is much lower than the allowable level of Cu2+ in drinking water set by U.S. Environmental Protection Agency (~20μM) and the World Health Organization (~30μM). The 1:1 binding process was confirmed by fluorescence measurements, IR analysis and DFT studies. Moreover, sensor ADA was successfully applied for determination of trace level of Cu2+ with 4 reuse cycles in various water samples, which affords promising potential in ion-detection field.
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•A reversible, colorimetric and water-soluble fluorescent sensor ADA was developed.•ADA exhibited on-off fluorescence detection of Cu2+ based on CHEQ.•The lower detection limit is determined to be 15.8nM.•The sensing mechanism of the sensor ADA for Cu2+ was proposed.•Sensor ADA was applied for trace Cu2+ analysis in environmental water samples.
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•A simple fluorescent turn-on chemosensor L for Pb2+ was developed.•Sensor L exhibited an excellent selectivity and high sensitivity toward Pb2+.•The quite low detection limit for ...Pb2+ was found to be 3.80×10−7M.•The Pb2+ recognition can function well within a wide pH range.
A simple highly sensitive and selective turn-on fluorescent chemosensor L based on bis-Schiff-base for Pb2+ ions was synthesized and characterized by spectroscopic techniques. L having high binding affinity towards Pb2+ ions of 2.10×104M−1 selectively detects Pb2+ ions with almost no interference among various competitive ions by a 11-fold fluorescent enhancement in CH3CN/H2O (95:5, v/v) solution over a wide pH range. Moreover, sensor L displayed a lower detection limit of 3.80×10−7M, which is low enough for sensing sub-millimolar concentration of Pb2+ encountered practically.
