A Simple Colorimetric Sensor with High Selectivity for Mercury Cation in Aqueous Solution

Abstract

A simple and sensitive mercapto thiadiazole Schiff-base colorimetric chemosensor 2 was synthesized. It exhibits good selectivity and sensitivity for the mercury cation over other metal cations such as Zn²⁺, Pb²⁺, Cd²⁺, Ni²⁺, Co²⁺, Ag⁺, Ca²⁺, Mg²⁺, and Cr³⁺ in both aqueous solution and on paper-made test kits. The change in color is very easily observed by the naked eye for the presence of Hg²⁺ cation, whereas other metal cations do not induce such a change. The chemosensor 2 showed remarkably anti-interference ability toward other metal cations and the detection limit toward Hg²⁺ was 1.5 × 10^?5 M.

GRAPHICAL ABSTRACT      

基于四丹磺酰胺杯[4]芳烃的汞离子荧光化学传感器

我们方便地合成了上沿修饰四丹磺酰胺基团的杯[4]芳烃衍生物1,发现该化合物在含50％水的乙腈中显示出对汞离子高选择性和灵敏性的识别作用,竞争实验表明多数金属离子对其检测干扰较小。机理研究结果表明荧光萃灭源于由丹磺酰胺基团到汞离子的光致电子转移过程。另外,通过研究1和1-Hg2+的荧光衰减实验,以及对比双丹磺酰胺杯[4]芳烃2和单丹磺酰胺杯[4]芳烃3对汞离子的识别作用,发现化合物1的四丹磺酰胺基团具有很好的预组织和协同作用。化合物1对汞离子的检测限为3.41×10-6 mol·L-1,这可以使1成为一个潜在的汞离子荧光化学传感器。     

A pH optical and fluorescent sensor based on rhodamine modified on activated cellulose paper

A rhodamine‐based colorimetric and fluorescent pH chemosensor ( RhA ) was designed and synthesized via a coupling reaction between rhodamine ethylenediamine and succinic anhydride. RhA showed excellent pH response in aqueous solutions. In addition, common cations (Na⁺, K⁺, Ag⁺, Mg²⁺, Ca²⁺, Pb²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺, Hg²⁺, Al³⁺, Cr³⁺, Fe³⁺, Au³⁺, Pt²⁺, and Ru²⁺) did not interfere with the pH response. As it has the potential to be used as a portable pH sensor, RhA was immobilized on activated cellulose paper using N,N'‐dicyclohexylcarbodiimide (DCC) and N,N'‐dimethylpyridin‐4‐amine (DMAP) as the coupling reagent to obtain a composite pH sensor ( CP‐RhA ). CP‐RhA was characterized by ATR‐FTIR, UV–vis, and fluorescence spectroscopy, and by scanning electron microscopy (SEM). CP‐RhA showed a rapid response in the pH range 1–8 through color and fluorescence changes. DFT calculations showed a blue‐shifted spectrum in the protonated form compared to the neutral form. Moreover, the pH sensor paper could be reused by dipping in NaOH. Thus, our work demonstrates the potential of the rhodamine dye composite for visualizing pH changes in real systems.     

A new rhodamine-based fluorescent chemosensor for transition metal cations synthesized by one-step facile condensation

A new rhodamine-based fluorescent chemosensor (1) for transition metal cations was synthesized by one-step facile condensation of rhodamine B and 2-aminopyridine. Without metal cations, 1 is colorless and nonfluorescent, whereas addition of metal cations (Fe³⁺, Hg²⁺, Pb²⁺, and Fe²⁺) leads to an obvious color change to pink and an appearance of orange fluorescence.     

A novel naphthalimide–glutathione chemosensor for fluorescent detection of Fe3+ and Hg2+ in aqueous medium and its application

By rationally introducing glutathione functionalized 1, 8–naphthalimide, a novel fluorescent chemosensor (NG) was successfully synthesized. NG can high selectively and sensitively recognize Fe³⁺/Hg²⁺ ions through quenching of fluorescence among all kinds of common metal ions in aqueous medium. The binding stoichiometry ratio of NG–Fe³⁺ is verified as 2:1and NG–Hg²⁺ as 1:2 confirmed by Job's plot method, FT-IR, ¹H NMR and ESI–MS spectrum, and the possible sensing mechanism were also proposed. The chemosensor NG toward Fe³⁺ and Hg²⁺ displays the excellent advantages of high selectivity and sensitivity, low detection limits (7.92?×?10^?8 and 4.22?×?10^?8?M), high association constants (3.37?×?10⁸ and 8.14?×?10⁴?M^?2), instataneous response (about 10s) and wide pH response range (3.0–8.0). Importantly, the chemosensor NG was successfully applied to determine Hg²⁺ in tap water. Meanwhile, the test strips based on NG were prepared, which could conveniently and efficiently detect Fe³⁺ and Hg²⁺. Moreover, the complex of NG and Fe³⁺ (NG–Fe³⁺) showed high selectivity and sensitivity for H₂PO₄￣ over many other anions in the same medium.     

Highly Selective Chromium(III) PVC‐Membrane Electrodes Based on Some Recently Synthesized Schiff's Bases

Three recently synthesized Schiff's bases were studied to characterize their ability as Cr³⁺ ion carrier in PVC‐membrane electrodes. The polymeric membrane (PME) and coated glassy carbon (CGCE) electrodes based on 2‐hydroxybenzaldehyde‐O,O′‐(1,2‐dioxetane‐1,2‐diyl) oxime (L1) exhibited Nernstian responses for Cr³⁺ ion over wide concentration ranges (1.5×10^?6–8.0×10^?3 M for PME and 4.0×10^?7–3.0×10^?3 M for CGCE) and very low limits of detection (1.0×10^?6 M for PME and 2.0×10^?7 M for CGCE). The proposed potentiometric sensors manifest advantages of relatively fast response and, most importantly, good selectivities relative to a wide variety of other cations. The selectivity behavior of the proposed Cr³⁺ ion‐selective electrodes revealed a considerable improvement compared to the best previously PVC‐membrane electrodes for chromium(III) ion. The potentiometric responses of the electrodes are independent of pH of the test solution in the pH range 3.0–6.0. The electrodes were successfully applied to determine chromium(III) in water samples.     

Selective Detection of Hg2+ Ions with Boron Dipyrromethene‐Based Fluorescent Probes Appended with a Bis(1,2,3‐triazole)amino Receptor

By using a copper‐promoted alkyne–azide cycloaddition reaction, two boron dipyrromethene (BODIPY) derivatives bearing a bis(1,2,3‐triazole)amino receptor at the meso position were prepared and characterized. For the analogue with two terminal triethylene glycol chains, the fluorescence emission at 509 nm responded selectively toward Hg²⁺ ions, which greatly increased the fluorescence quantum yield from 0.003 to 0.25 as a result of inhibition of the photoinduced electron transfer (PET) process. By introducing two additional rhodamine moieties at the termini, the resulting conjugate could also detect Hg²⁺ ions in a highly selective manner. Upon excitation at the BODIPY core, the fluorescence emission of rhodamine at 580 nm was observed and the intensity increased substantially upon addition of Hg²⁺ ions due to inhibition of the PET process followed by highly efficient fluorescence resonance energy transfer (FRET) from the BODIPY core to the rhodamine moieties. The Hg²⁺‐responsive fluorescence change of these two probes could be easily seen with the naked eye. The binding stoichiometry between the probes and Hg²⁺ ions in CH₃CN was determined to be 1:2 by Job′s plot analysis and ¹H NMR titration, and the binding constants were found to be (1.2±0.1)×10¹¹ m ^?2 and (1.3±0.3)×10¹⁰ m ^?2, respectively. The overall results suggest that these two BODIPY derivatives can serve as highly selective fluorescent probes for Hg²⁺ ions. The rhodamine derivative makes use of a combined PET‐FRET sensing mechanism which can greatly increase the sensitivity of detection.     

Complexation of metal ions with the novel diazadithia crown ether carrying two anthryl pendants in acetonitrile–tetrahydrofuran

A new crown ether carrying two anthryl groups with nitrogen–sulfur donor atom was designed and synthesized by the reaction of the corresponding macrocyclic compound and 9-chloromethyl anthracene. The influence of metal cations such as Al³⁺, Zn²⁺, Fe²⁺, Fe³⁺, Co²⁺, Ni²⁺, Mn²⁺, Cu²⁺, Cd²⁺, Hg²⁺ and Pb²⁺ on the spectroscopic properties of the ligand was investigated in acetonitrile–tetrahydofuran solution (1/1) by means of absorption and emission spectrometry. Absorption spectra show isosbestic points in the spectrophotometric titration of Fe²⁺, Fe³⁺, Al³⁺, Cu²⁺ and Hg²⁺. The results of spectrophotometric titration experiments disclosed the complexation stoichiometry and complex stability constant of the novel ligand with Fe²⁺, Fe³⁺, Al³⁺, Cu²⁺and Hg²⁺cations. The presence of excess amounts of Al³⁺, Zn²⁺, Fe²⁺, Fe³⁺, Co²⁺, Ni²⁺, Mn²⁺, Cu²⁺, Cd²⁺, Hg²⁺ and Pb²⁺ cations caused an enhancement of anthryl fluorescence. The ligand showed good sensitivity for Zn²⁺ with respect to other metal cations with linear range and detection limit of 1.4 × 10^?7 to 4.1 × 10^?6 M and 1.0 × 10^?8 M respectively.     

Water‐soluble hyperbranched polyelectrolytes with high fluorescence quantum yield: Facile synthesis and selective chemosensor for Hg2+ and Cu2+ ions

New water‐soluble hyperbranched polyfluorenes bearing carboxylate side chains have been synthesized by the simple “A2 + B2 + C3” protocol based on Suzuki coupling polymerization. The linear polyfluorene analogue LPFA was also synthesized for comparative investigation. The optical properties of the neutral precursory polymers in CHCl₃ and final carboxylic‐anionic conjugated polyelectrolytes in buffer solution were investigated. The obtained hyperbranched polyelectrolyte HPFA2 with lower content of branch unit (2%) showed excellent solubility and high fluorescence quantum yield (?_F = 89%) in aqueous solution. Fluorescence quenching of HPFA2 by different metal ions was also investigated, the polyelectrolyte showed high selectivity for Hg²⁺ and Cu²⁺ ions relative to other various metal ions in buffer solution. The Stern‐Volmer constant K_sv was determined to be 0.80 × 10⁶ M^?1 for Hg²⁺ and 3.11 × 10⁶ M^?1 for Cu²⁺, respectively, indicating the potential application of HPFA2 as a highly selective and sensitive chemosensor for Hg²⁺ and Cu²⁺ ions in aqueous solution. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3431–3439, 2010     

A highly selective colorimetric sensor for Hg2+ based on a copper (II) complex of thiosemicarbazone in aqueous solutions

By applying an indirect strategy, a new copper (Ⅱ) complex of a thiosemicarbazone L has been successfully developed as a colorimetric chemosensor for the sensitive detection of mercury (Ⅱ) ions. In the presence of copper (Ⅱ) ions, the colorless solution of L became yellow; however, upon the addition of traces of mercury (Ⅱ) ions, the yellow color faded to colorless immediately. Other ions, including Fe3+ , Ag+ , Ca2+ , Zn2+ , Pb2+ , Cd2+ , Ni2+ , Co2+ , Cr3+ and Mg2+ had a negligible influence on the probe behavior. The detection limits were 5.0×10 -6 M and 3.0×10 -7 M of Hg2+ using the visual color changes and UV-vis changes respectively. Test strips based on Cu-L were fabricated, which could act as a convenient and efficient Hg2+ test kits.     

A New Fluorescent Chemosensor for Metal Ions Based upon 1,8‐Naphthalimide and 8‐Hydroxyquinoline

A new fluorescent chemosensor based upon 1,8‐naphthalimide and 8‐hydroxyquinoline was synthesized, and its fluorescent properties in the presence of different metal cations (Hg²⁺, Ag⁺, Zn²⁺, Fe²⁺, Cd²⁺, Pb²⁺, Ca²⁺, Cu²⁺, Mg²⁺, and Ba²⁺) were investigated. It displayed fluorescence quenching with some heavy and transition metal (HTM) ions, and the quenching strongly depended on the nature of HTM ions.     

Synthesis and selective recognition toward zinc ion of chiral poly(imine‐triazole)

A novel AB type of clickable monomer, (S)‐2‐[(2‐azido‐1‐phenylethylimino)methyl]‐5‐propargyloxyphenol (AMPP) was designed and polymerized to yield a class of main‐chain chiral poly(imine‐triazole)s through the metal‐free click reaction. With the thermally induced polymerization, the desired polytriazoles can be easily prepared in high yields by a stepwise heating‐up process and have the number‐average molecular masses ranging from 5.1 × 10³ to 58.1 × 10³ (polydispersity indices = 1.38?1.68). The polymers were characterized by Fourier Transform Infrared spectroscopy (FTIR), ¹H Nuclear Magnetic Resonance (NMR), and gel permeation chromatography, and their optical properties were studied by fluorescence and circular dichroism (CD) spectroscopies. As a chemosensor, these polymers exhibited a selective “turn‐on” fluorescence enhancement response toward Zn²⁺ ion over other cations such as Na⁺, K⁺, Mg²⁺, Ca²⁺, Ag⁺, Pb²⁺, Cd²⁺, Hg²⁺, Mn²⁺, and Ni²⁺ in dimethyl sulfoxide. However, the Zn²⁺‐induced fluorescence signal was subject to serious interference by Al³⁺, Cu²⁺, Cr³⁺, and Fe³⁺ ions. Interestingly, the chiral polymer showed distinctive changes in the CD spectra on complexation with Zn²⁺, which allowed for the discrimination of this ion in the presence of other species tested including those interfering ions observed in the fluorescent detection. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2248–2257     

A highly selective colorimetric and fluorescent chemosensor for Cr2+ in aqueous solutions

A new rhodamine-based chemosensor was synthetized through a modified copper-catalyzed [3+2]-cycloaddition of an azidocoumarin with an alkynyl-rhodamine. Its sensing properties toward various metal cations in aqueous solutions were investigated by colorimetric changes, UV–vis and fluorescence spectroscopies. The sensor exhibited a high selectivity for Cr²⁺ over Cr³⁺ and other divalent cations such as Cu²⁺, Mg²⁺, Zn²⁺, Ca²⁺, Cd²⁺, Co²⁺, Hg²⁺ and Ni²⁺. The linear range of detection by fluorescence spectroscopy is 0.07–3.5 mM, with a detection limit of ca. 64 μM. The binding mode of Cr²⁺ with the sensor was rationalized through experimental evidences.     

A Dinuclear Ruthenium(II) Complex as a One‐ and Two‐Photon Luminescent Probe for Biological Cu2+ Detection

A new dinuclear Ru^II polypyridyl complex, [(bpy)₂Ru(H₂bpip)Ru(bpy)₂]⁴⁺ ( RuH₂bpip , bpy=2,2‐bipyridine, H₂bpip=2,6‐pyridyl(imidazo[4,5‐f][1,10]phenanthroline), was developed to act as a one‐ and two‐photon luminescent probe for biological Cu²⁺ detection. This Ru^II complex shows a significant two‐photon absorption cross section (400 GM) and displays a remarkable one‐ and two‐photon luminescence switch in the presence of Cu²⁺ ions. Importantly, RuH₂bpip can selectively recognise Cu²⁺ in aqueous media in the presence of other abundant cellular cations (such as Na⁺, K⁺, Mg²⁺, and Ca²⁺), trace metal ions in organisms (such as Zn²⁺, Ag⁺, Fe³⁺, Fe²⁺, Ni²⁺, Mn²⁺, and Co²⁺), prevalent toxic metal ions in the environment (such as Cd²⁺, Hg²⁺, and Cr³⁺), and amino acids, with high sensitivity (detection limit≤3.33×10^?8 M ) and a rapid response time (≤15 s). The biological applications of RuH₂bpip were also evaluated and it was found to exhibit low cytotoxicity, good water solubility, and membrane permeability; RuH₂bpip was, therefore, employed as a sensing probe for the detection of Cu²⁺ in living cells and zebrafish.     

A Fluorescent Chemosensor for Dihydrogen Phosphate Ion Based on 2‐[2‐Hydroxy‐4‐(diethylamino) phenyl]‐1H‐imidazo[4,5‐b]phenazine‐Fe3+ Ensemble

A long wavelength emission fluorescent (612 nm) chemosensor with high selectivity for H₂PO₄^? ions was designed and synthesized according to the excited state intramolecular proton transfer (ESIPT). The sensor can exist in two tautomeric forms ('keto' and 'enol') in the presence of Fe³⁺ ion, Fe³⁺ may bind with the 'keto' form of the sensor. Furthermore, the in situ generated GY‐Fe³⁺ ensemble could recover the quenched fluorescence upon the addition of H₂PO₄^? anion resulting in an off‐on‐type sensing with a detection limit of micromolar range in the same medium, and other anions, including F^?, Cl^?, Br^?, I^?, AcO^?, HSO₄^?, ClO₄^? and CN^? had nearly no influence on the probing behavior. The test strips based on 2‐[2‐hydroxy‐4‐(diethylamino) phenyl]‐1H‐imidazo[4,5‐b]phenazine and Fe³⁺ metal complex ( GY‐Fe³⁺ ) were fabricated, which could act as convenient and efficient H₂PO₄^? test kits.     

Synthesis of Novel 4‐((Substituted bis‐indolyl)methyl)‐benzo‐15‐crown‐5 for the Colorimetric Detection of Hg2+ Ions in an Aqueous Medium

A practical, two‐step synthesis of novel 4‐(substituted bis‐indolyl)methyl)benzo‐15‐crown‐5 has been reported. The strategy employed for the synthesis of the desired molecules involved Duff formylation of benzo‐15‐crown‐5 to get 4‐formyl benzo‐15‐crown‐5 followed by subsequent reactions with substituted indoles in trifluoroacetic acid to yield novel 4‐(substituted bis‐indolyl)methyl)benzo‐15‐crown‐5 in moderate to good yield. One of the reported novel molecule tested for the complexation behavior with various metal cations, such as Li⁺, Na⁺, K⁺, Mg²⁺ Ca²⁺, Al³⁺, Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺, Sn²⁺, Ba²⁺, Hg²⁺, and Pb²⁺, showed a visual colorimetric probe for the detection of mercury cations (Hg²⁺) in an aqueous medium.     

Chromo-chemodosimetric detection for Fe2+ by Fenton reagent-induced chromophore-decolorizing of halogenated phenolsulfonphthalein derivatives

A commercially-available sulfonphthalein derivative was demonstrated to be a chemodosimeter for Fe²⁺ and its sensing behavior was further investigated by UV-vis spectroscopy in aqueous media under the optimum conditions. In the presence of chlorophenol red (CPR) and H₂O₂, the absorption maximum at 435 nm decreased upon addition of Fe²⁺, resulting in a significant color change of the CPR solution from yellow to colorless. The chemosensor system did not show significant responses to a series of other metal ions including Al³⁺, Zn²⁺, Cd²⁺, Hg²⁺, Mn²⁺, Co²⁺, Fe³⁺, Ni²⁺, Cu²⁺, La³⁺, Ce⁴⁺, Th⁴⁺, Pd²⁺, Pb²⁺, Sb³⁺, Cr³⁺, Au³⁺, Ag⁺, Nd³⁺, Sm³⁺, alkali and alkaline earth metal cations, allowing for highly selective naked-eye detection of Fe²⁺. Quantitative analysis was carried out kinetically for practicable the Fe²⁺ assay when either fixed time method or the initial rate method was applied. When the detecting time was set, the decrease of absorbance signal was linear with Fe²⁺ concentration in the range of 0 to 7.50 × 10^?5 mol L^?1 and the regression equation was ΔA = 0.00759 + 0.00593C _Fe with a correlation coefficient r = 0.9953. The chemodosimetric system has employed an irreversible Fenton reagent-promoted oxidation of the CPR free chromophore and the hydroxyl radicals were generated in the presence of both Fe²⁺ and hydrogen peroxide. The mechanistic interpretation of the signaling process was partially confirmed by the radical scavenging experiment and the FT-IR analysis of the intermediates formed at different reaction periods.     

All Solid State Chromium(III) Selective Potentiometric Sensor Based on 2‐(1‐(2‐((3‐(2‐Hydroxyphenyl)‐1H‐pyrozol‐1‐yl)methyl)benzyl)‐1H‐pyrazol‐3‐yl)phenol

Highly selective all solid state electrochemical sensor based on a synthesized compound i.e. 2‐(1‐(2‐((3‐(2‐hydroxyphenyl)‐1H‐pyrozol‐1‐yl)methyl)benzyl)‐1H‐pyrazol‐3‐yl)phenol (I) as an ionophore has been prepared and investigated for the selective quantification of chromium(III) ions. The effect of various plasticizers, viz. dibutyl phosphonate (DBP), dibutyl(butyl) phosphonate (DBBP), nitrophenyl octyl ether (NPOE), tris‐(2‐ethylhexyl)phosphonate (TEP), tri‐butyl phosphonate (TBP), dioctyl phthalate (DOP), dioctyl sebacate (DOS), benzyl acetate (BA) and acetophenone (AP) along with anion excluders NaTPB (sodium tetraphenyl borate) and KClTPB (potassium(tetrakis‐4‐chlorophenyl)borate was also studied. The optimum composition of the best performing membrane contained (I):KClTPB:NPOE:PVC in the ratio 15 : 3 : 40 : 42 w/w. The sensor exhibited near Nernstian slope of 20.1±0.2 mV/decade of activity in the working concentration range of 1.2×10^?7–1.0×10^?1 M, and in a pH range of 3.8–4.5. The sensor exhibited a fast response time of 10 s and could be used for about 5 months without any considerable divergence in potentials. The proposed sensor showed very good selectivity over most of the common cations including Na⁺, Li⁺, K⁺, Cu²⁺, Sr²⁺, Ni²⁺, Co²⁺, Ba²⁺, Hg²⁺, Pb²⁺, Zn²⁺, Cs⁺, Mg²⁺, Cd²⁺, Al³⁺, Fe³⁺and La³⁺. The activity of Cr(III) ions was successfully determined in the industrial waste samples by using this sensor.     

Complexation of metal ions with the novel diazadithia crown ethers carrying two pyrene pendants in acetonitrile-tetrahydrofuran

Two crown ethers carrying pyrene side arms with nitrogen-sulfur donor atom were designed and synthesized by the reaction of the corresponding macrocyclic compounds and 1-bromomethyl-pyrene. The influence of metal cations such as Al³⁺, Zn²⁺, Fe²⁺, Fe³⁺, Co²⁺, Ni²⁺, Mn²⁺, Cu²⁺, Cd²⁺, Hg²⁺ and Pb²⁺ on the spectroscopic properties of the ligands was investigated in acetonitrile-tetrahydrofuran (1:1) by means of absorption and emission spectrometry. Absorption spectra show isosbestic points in the spectrophotometric titration of Al³⁺, Zn²⁺, Fe²⁺, Ni²⁺, Cu²⁺, and Pb²⁺ with 16-membered crown ether. Similar results were obtained for Al³⁺, Fe²⁺, Hg²⁺, Cu²⁺ and Pb²⁺ with 14-membered crown ether. The results of spectrophotometric titration experiments disclosed the complexation stoichiometry and complex stability constants of the novel ligands with these cations. According to spectrofluorimetric titration measurements the 14-membered diazadithia crown ether showed sensitivity for Pb²⁺ with linear range and detection limit of 1.3 × 10^?6 to 5.2 × 10^?5 M and 5.2 × 10^?7 M, respectively. The 16-membered diazadithia crown ether showed sensitivity for Ni²⁺ with linear range and detection limit of 1.3 × 10^?7 to 5.2 × 10^?6 M and 4.1 × 10^?8 M, respectively.     

BODIPY Immobilized MCM-41 Based Multianalyte Sensor: Application in Detection and Removal of Trivalent (Al3+, Cr3+) and Divalent (Cu2+, Hg2+) Metal Ions in Aqueous Media

In the present study, a novel p-phenylcarboxylic acid BODIPY ( L ) immobilized MCM-41 based solid chemosensor material L-propylsilyl@MCM-41 ( MS4 ) was developed to detect multiple metal ions in a pure aqueous medium. The synthesized solid chemosensor material MS4 shows high sensitivity and removal ability towards trivalent (Al³⁺, Cr³⁺) and divalent (Cu²⁺, Hg²⁺) metal ions. The emission intensity of MS4 enhanced multifold selectively in the presence of trivalent (Al³⁺, Cr³⁺) metal ions and shows quenching in the presence of divalent (Cu²⁺, Hg²⁺) metal ions. The limit of detection was calculated to be in the nanomolar range with Al³⁺, Cr³⁺, Cu²⁺_, and Hg²⁺ metal ions in the aqueous medium. The spectroscopic and analytical results suggest that MS4 selectively binds with Al³⁺ and Cr³⁺ through −NH functionality and with Hg²⁺ and Cu²⁺ through −COOH functionality of p-phenylcarboxylic acid BODIPY ( L ). Further, MS4 selectively removes Al³⁺, Cr³⁺, Cu²⁺, and Hg²⁺ metal ions from the aqueous media with removal efficiency of 97.28 %, 96.34 %, 87.19 %, and 95.63 %, respectively. No noticeable change in the concentration was observed for other metal ions. The recycling potential of MS4 was evaluated using EDTA for up to seven cycles with no significant reduction in sensing capability.