Colorimetric Probe Research Articles

Pomegranate peel extract for green synthesis of magnetite (Fe3O4) nanozymes as a colorimetric probe for determination of diclofenac

A nanozyme based on Fe3O4 was constructed for colorimetric detection of diclofenac in pharmaceutical formulations. Firstly, an eco-friendly, rapid, and simple green approach was introduced to synthesize magnetite (Fe3O4) nanoparticles. Pomegranate peel extract was employed as a green reducing and stabilizing agent. The synthesized magnetite NPs were characterized by field emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, ultraviolet–visible spectroscopy, energy-dispersive X-ray spectroscopy, BET, X-ray diffraction, and zeta potential (Ƶ) techniques and have an average size of 14.24 nm. In the presence of hydrogen peroxide, a redox interaction takes place, and the resulting hydroxyl promotes a colorimetric conversion from colorless to blue in the presence of 3,3′,5,5′-tetra-methyl-benzidine (TMB). In addition, diclofenac can inhibit colorimetric conversion once it competes with TMB’s interaction with hydroxyl. There is a relationship between the colorimetric distinction and the target amount. It is also obvious that there is a colorimetric distinction between diclofenac and TMB due to their competition. The signal responses to diclofenac are linear in the range of 0.1–75 mg/L, and the limit of detection is 0.01 mg/L. In practical assays of diclofenac in pharmaceutical formulations, the relative standard deviation of the sample tests is 0.51 %, and the recovery for the spiked assays is 96.93 % with an RSD of 1.68 %. The effects of different interferences were studied with recovery ranging from 95.02 to 99.93 %

Hyperbranched Thermosensitive Polymer-AuNP Composite Probe for Temperature Colorimetric Detection

Temperature detection is particularly important in the medical and scientific fields. Although there are various temperature detection methods, most of them focus on broad temperature detection, and basic research in specific fields, especially the detection of subtle temperature changes (32–34 °C) during wound infection, is still insufficient. For this purpose, a novel colorimetric temperature sensing probe is designed in this paper, which can quickly and intuitively respond to small temperature changes within a specific range through color changes. In this paper, hyperbranched polyethyleneimine (HPEI) was modified by isobutyrylation to prepare hyperbranched temperature-sensitive polymer (HPEI-IBAm). And it was combined with gold nanoparticles (AuNPs) prepared by a sodium citrate reduction method to construct an HPEI-IBAm-AuNP colorimetric probe. The probe exhibits excellent stability, even at salt concentrations of up to 12 g/L, thanks to the abundant amino functional groups and the large steric hindrance effect unique to HPEI-IBAm. In particular, the temperature detection range of the probe is precisely locked within 32–34 °C, enabling it to respond quickly and accurately to small temperature changes of only 2 °C. This feature is perfectly suited to the practical needs of temperature detection in infected wounds. The linear fitting coefficient of the temperature response is as high as 0.9929, ensuring the accuracy of the test results. The detection performance of the probe remained highly consistent over 10 cycles, fully proving its excellent reusability and durability. In addition, a flexible colorimetric sensor was prepared by combining the probe with polydimethylsiloxane (PDMS) film. This sensor is capable of rapidly detecting human skin temperature in real time, achieving an accuracy of 99.07% to 100.61%. It can provide a possible solution to the challenges of delayed and difficult temperature detection caused by different body parts and uneven surfaces, among others. This demonstrates its extensive practical value and potential, and it is expected to be further applied in the monitoring of wound infections.

Development of colorimetric probe using robust zinc-MOF and its consistent melamine sponge composite: Instantaneous N3–, La3+ sensing and degradation applications

The crystalline sponge method (CSM), which involves soaking a target molecule into a crystalline metal-organic framework (MOF), offers a promising approach by eliminating the need for high-quality single crystals of the target compound. To broaden the scope of compounds that can be analyzed using CSM, it is essential to investigate various MOFs. In this study, we focused on evaluating the potential of a zinc-based MOF, specifically [Zn3(Cei)2((Bimb)3] (Zinc-MOF), as a CSM host. We successfully synthesized and thoroughly characterized Zinc-MOF. Additionally, we developed a Zinc-MOF@melamine sponge (Zinc-MOF@MS) composite, which exhibited significant photocatalytic activity by degrading hazardous organic dyes such as Rose Bengal (RB) and Crystal Violet (CV), achieving degradation efficiencies of 98.95 % and 92.51 %, respectively, after 120 min of exposure to visible sunlight. The luminescent properties of the Zinc-MOF were also explored, demonstrating strong luminescent emission and excellent chemical stability. Furthermore, Zinc-MOF showed remarkable sensing capabilities, selectively detecting La³⁺ cations and N₃⁻ anions in aqueous solutions through luminescence quenching.

Mitochondria-Targeted NIR Ratiometric and Colorimetric Fluorescent Probe for Biothiols Based on a Thiol-Chromene Click Reaction.

In this work, a mitochondria-targeted NIR ratiometric and colorimetric fluorescent probe 1 was tactfully designed and synthesized by a novel design strategy of modifying chromene to pyridine for the first time. 1 exhibited a maximum absorption peak at 508 nm and a maximum fluorescence emission peak at 650 nm. Under the stimulus of biothiols (cysteine (Cys), homocysteine (Hcy), and glutathione (GSH)), the maximum absorption and fluorescence emission peaks of 1 blue-shifted to 448 and 541 nm, respectively, along with color changes from red to yellow under visible light and from red to green under a 365 nm ultraviolet (UV) lamp, which can be ascribed to the click reaction of biothiols with the α,β-unsaturated ketone of the chromene moiety with pyran ring-opening, phenol formation, and 1,6-elimination of the p-hydroxybenzyl moiety. 1 detected biothiols (Cys, GSH, and Hcy) with high sensitivity (LODs of 29, 23, and 16 nM for Cys, GSH, and Hcy, respectively), excellent selectivity, and fast response. Moreover, 1 can target mitochondria and image the fluctuation of intracellular biothiols by dual-emission channels.

Reactive Fluorescent and Colorimetric Probe for Highly Selective and Sensitive Detection of Hg2+ in Real Water Samples.

Construction of efficient chemosensors for highly specific and sensitive detection of mercury ions remains a great challenge. In this work a highly selective and sensitive probe CY was designed and synthesized by using coumarin fluorophore as the matrix and thioacetal moiety as the reactive recognition site for Hg2+. By virtue of the thiophilicity of Hg2+, probe CL could be hydrolyzed to deprotect and the thioacetal was transformed to the acyl group after the addition of Hg2+, the blue-green fluorescence was quenched and meanwhile the solution changed from light green to yellow. The detection limit of probe CY for Hg2+ was as low as 6.8 nM, and it could completely react with Hg2+ within 3min. Moreover, probe CY exhibited good resistance against interference from competitive metal ions and biothiols, high stability in pH 1-11 and applicability for fluorogenic and chromogenic dual-modal detection of Hg2+ in real water samples over a broad range of pH 5-10.

Development of microfibrillated cellulose-reinforced carboxymethyl cellulose dipstick imprinted with benzotrifluoride-bearing hydrazone sensor for colorimetric detection of organophosphonate.

The colorless and odorless nerve agents can cause paralysis and even death. The development of novel composite-based microporous strips has allowed for the rapid and visual detection of diisopropyl phosphorofluoridate (DIPF) nerve agent mimics. The active methyl-containing tricyanofuran and 4-aminobenzotrifluoride diazonium salt were azo-coupled in a straightforward manner to produce a new benzotrifluoride (BFT)-comprising tricyanofuran (TCF) hydrazone colorimetric probe. The molecular structure of the benzotrifluoride-bearing hydrazone (BFTH) was explored by different spectroscopic techniques. Microfibrillated cellulose (MFC) was produced using a green process from sugarcane bagasse, an agriculture waste that is notorious for being a solid pollution. Consequently, discovering a straightforward procedure to convert bagasse into valuable materials has been of utmost importance. MFC displayed diameters of 0.25-2 μm, whereas the sensory films exhibited pore diameters of 0.5-2.25 μm. Various quantities of the BFTH chromophore were used to create benzotrifluoride-bearing hydrazone/microfibrillated cellulose/carboxymethyl cellulose (BFTH/MFC@CMC) composites. The absorbance band of the hydrazone-immobilized composite increased from 435 nm to 580 nm as the content of DIPF was raised. When exposed to DIPF, the dipstick color shifted from orange to pink, according to the CIE Lab measurements. The sensor strip showed a detection limit to DIPF between 5 and 200 ppm.

A colorimetric fluorescent probe for reversible detection of HSO3−/H2O2 and effective discrimination of HSO3−/ClO− and its application in food and bioimaging

In view of the significant role of reactive sulfur species (RSS) and reactive oxygen species (ROS) in maintaining the redox homeostasis of organisms, we proposed a colorimetric fluorescent probe (HTN) for reversible detection of HSO3−/H2O2 and effective discrimination of HSO3−/ClO−. C = C is the active site for the Michael addition of HSO3− and the oxidation of ClO−. When HTN interacts with HSO3− and ClO−, it exhibits fluorescence quenching. The addition of oxidizing H2O2 to the system can restore the conjugate structure of the addition product of HSO3− (HTN-HSO3−) and the fluorescence recovery, but it cannot restore the structure of the oxidation product of ClO− (HTN-ClO−). By studying the change of the reversibility/non-reversibility of the probe structure with the addition of H2O2, the purpose of reversible detection of HSO3−/H2O2 and distinguishing HSO3−/ClO− is achieved. In addition, HTN can not only be used as a fluorescent ink to detect HSO3− on the test paper, but also has excellent detection effect on HSO3− and ClO− in real food samples and water samples. Meantime, HTN has good biocompatibility and can target mitochondria to achieve reversible detection of HSO3−/H2O2 and effective discrimination of HSO3−/ClO− in living cells. Therefore, HTN has great potential as a molecular tool for studying redox homeostasis in the interaction network of complex living systems.

Mycotoxin Detection through Colorimetric Immunoprobing with Gold Nanoparticle Antibody Conjugates.

Driven by their exceptional optical characteristics, robust chemical stability, and facile bioconjugation, gold nanoparticles (AuNPs) have emerged as a preferred material for detection and biosensing applications in scientific research. This study involves the development of a simple, rapid, and cost-effective colorimetric immuno-sensing probe to detect aflatoxin B1 and zearalenone using AuNP antibody (AuNP-mAb) conjugates. Anti-toxin antibodies were attached to the AuNPs by using the physical adsorption method. The colorimetric immunosensor developed operates on the principle that the optical properties of the AuNP are very sensitive to aggregation, which can be induced by a critical high salt concentration. Although the presence of antibodies on the AuNP surface inhibits the aggregation, these antibodies bind to the toxin with higher affinity, which leads to exposure of the surface of AuNPs and aggregation in a salt environment. The aggregation triggers a noticeable but variable alteration in color from red to purple and blueish gray, as a result of a red shift in the surface plasmon resonance band of the AuNPs. The extent of the shift is dependent on the toxin exposure dose and can be quantified using a calibration curve through UV-Visible-NIR spectroscopy. The limit of detection using this assay was determined to be as low as 0.15 ng/mL for both zearalenone and aflatoxin B1. The specificity of the prepared immunoprobe was analyzed for a particular mycotoxin in the presence of other mycotoxins. The developed immunoprobe was evaluated for real-world applicability using artificially spiked samples. This colorimetric immunoprobe based on localized surface plasmon resonance (LSPR) has a reduced detection limit compared to other immunoassays, a rapid readout, low cost, and facile fabrication.

Development of 2D Ir-DMG nanosheets as a colorimetric sensor probe for Ni (II) sensing and a highly sensitive, reliable, and portable colorimetric sensor device for environmental analysis

The era of nanomaterials made a revolutionary change in colorimetric sensing with ultra-high sensitivity, improved reactivity, and enhanced photoactivity. The first-ever novel 2D metal–organic nanosheets were synthesized using IrCl3 and Dimethylglyoxime (DMG) by probe ultrasonication (PUS) followed by a solvothermal wet-chemical approach. This material has shown a rapid color change from yellow to crimson red with Ni (II) after the formation of complex. The UV–visible absorption spectra are the conventional methodology for colorimetric sensors and here, it was given a perfect linear relationship with an R2 of 0.99 and an LOD of 1.60 µM (0.1 ppm). The average calculated molar extinction coefficient for this system was 1889.30 M−1 cm−1. This is comparatively high absorptivity value. In addition, a novel Arduino-based colorimetric sensor device and corresponding software were developed under the name of “Chrom Metrics”. This Arduino device is unique since it can sense all wavelengths and the combined RGB delta E values. Therefore, it can provide more information/rationale for colorimetry than other devices/methods. The same Ir-DMG & Ni (II) system showed a perfect linear relationship with an R2 of 0.98 and a LOD of 0.85 µM (0.05 ppm) by the data obtained from this sensor device. Thus, this new device is easier and more accurate, highly efficient, rapid, highly selective, and sensitive.

Novel Colorimetric and Near-Infrared Ratiometric Fluorescent Probe for Sensing Cysteine in Food Samples, Plants, and Living Cells.

Cysteine (Cys) is a crucial biothiol that acts a significant function in food samples and biological systems, including plant roots and living cells. Hence, we developed a novel colorimetric and near-infrared ratiometric fluorescent probe (CT), composed of coumarin and tetrahydroacridine-conjugated indole salt, for the detection of Cys. Upon reaction with Cys, the probe undergoes a specific N-substitution reaction, resulting in a notable colorimetric change and a significant ratiometric fluorescent response in both visible and near-infrared emission channels. These dual-channel ratiometric fluorescence changes are completely independent, enabling the probe to obtain great selectivity, sensitivity, and exceptional detection accuracy. Leveraging these attributes, the probe was employed to provide accurate quantitative analysis of Cys in food samples. Furthermore, confocal imaging demonstrated that the probe could monitor both exogenous and endogenous Cys levels in living cells and track Cys changes in plant roots under heavy metal stress. This work presents a dependable and accurate imaging solution for tracking and identifying Cys of real food, plants, and living cells.

Controllable fabrication of high-quantum-yield bimetallic gold/silver nanoclusters as multivariate sensing probe for Hg2+, H2O2, and glutathione based on AIE and peroxidase mimicking activity

The grave threat posed by heavy metals and food hazards has increased the urgency of rapid and precise detection for food security and human health. Efficient multivariate sensing probes are imperatively required for sensing heavy metals and tumor markers, which are still facing great challenge in terms of multi-functional integration. Here, bimetallic gold-silver nanoclusters (NG-AuAgNCs) were developed with unique aggregation-induced-emission (AIE) property and peroxidase (POD) mimicking activity towards the efficient multivariate sensing via optimization of the precursors. The NG-AuAgNCs emitted at 614 nm and enable AIE feature with lifetime of 12.61 μs and high quantum yield of 40.5%. Possessing AIE and POD activity, the NG-AuAgNCs show great potential as fluorimetric and colorimetric dual-mode probe for multivariate sensing Hg2+, H2O2 and GSH, with good recoveries in real samples. The NG-AuAgNCs paper sensors further integrating with smartphone, achieved portable detection of Hg2+ with limit of detection (LOD) of 19 nM, while the colorimetric-mode presented consecutive response to H2O2 and GSH via a reversible oxidase tetramethylbenzidine process with LODs of 7.02 and 0.45 μM, respectively. This work not only demonstrates a multivariate probe for environment and human health, but also provides valuable insights for the function integration of the nanocluster via synthetic manipulation.

A novel yet facile colorimetric and fluorescent dual-channel salamo-type probe for highly effective detection of B4O72− ions in real water samples and its application

A novel yet facile colorimetric and fluorescent dual-channel salamo-type probe for highly effective detection of B4O72− ions in real water samples and its application

Colorimetric and Fluorimetric Detection of Fe(III) Using a Rhodamine-Imidazole Hydrazone Based Chemosensor: Photophysical Properties, DFT, TGA, and DSC Studies.

Rhodamine-imidazole hydrazones (RIH-1 & RIH-2) based chemosensors have been synthesized. These are characterised and evaluated by FT-IR spectroscopy, 1H-NMR, 13C-NMR, LCMS, absorption and fluorescence spectroscopy. These chemosensors exhibit enhanced sensitivity and selectivity in detecting the biologically significant Fe3+ metal ion through both colorimetric and fluorescence changes. The optical properties have been investigated using binary acetonitrile-water (7:3 v/v) semi-aqueous solution. The probe RIH-1 can be deployed as a fluorescent and colorimetric probe for the detection of Fe3+ ion. It shows an absorption band at 559nm and an intensity band at 579nm increasing up to 50-fold with the increase in the concentration of Fe3+ with the detection limit as low as 11nM. In the visible light, RIH-1 helps in the detection of Fe3+ ion through the naked eye, while the addition of Fe3+ to the probe RIH-1 results in a colour change from colourless to pink. This is primarily due to the opening of the lactone ring in RIH-1. Notably, RIH-1 probe displays a high quantum yield of 0.51, after binding with Fe3+ ions. Indeed, it has been found that sensor RIH-1 is very effective in sensing Fe3+ ions through both fluorescence based and visual detection methods. Additionally, DFT studies of these chemosensors have been evaluated, TGA and DSC analysis showed good thermal stability.

A novel dialdehyde cellulose-based colorimetric and turn-on fluorescent probe for H2S detection and its application in red wine

Hydrogen sulfide (H2S) is considered one of the most important gaseous transmitters in the metabolic system, and the abnormal concentration of H2S is associated with a variety of diseases. Up to now, it is still a challenge to develop a portable assay for H2S even though the research about the detection of H2S is booming. Herein, a novel bifunctional dialdehyde-cellulose fluorescent probe DAC-DPD was prepared with high selectivity and sensitivity to H2S with colorimetric and fluorescent “turn-on” characteristics, and the limit of detection (LOD) of DAC-DPD for H2S was 0.831 μM. The sensing mechanism of DAC-DPD's to H2S was a Michael addition reaction confirmed by HRMS, 1H NMR and density-functional theory (DFT) calculations. DAC-DPD can be used to detect H2S in red wine samples. In Addition, the prepared DAC-DPD embedded fluorescent membrane can be used as a reliable sensing platform for rapid detection of H2S. It provided a convenient and rapid detection material, simplifying the detection process of H2S, which is of great significance for the development of cellulose-based fluorescent smart material.

Towards portable kits for on-site colorimetric detection of aqueous hydrazine using piperidine-thiophene-barbituric acid push-pull probe.

Owing to the carcinogenicity and environmental risks as well as the wide industrial use of hydrazine, we report herein a colorimetric probe for its ratiometric detection in pure water. The developed probe possesses push-pull architecture with 2-(piperidyn-1-yl)thiophene as the donor, N,N'-dibutylbarbituric as the acceptor, and butadiene as the spacer. In contrast to weak solvatochromic behavior in organic solvents, the probe showed distinct optical photophysical properties in water resulting from the formation of nanoscopic aggregates. The probe underwent pronounced spectral changes upon the addition of hydrazine including an 11.5-fold decrease in absorbance and ~2.4-fold fluorescence quenching. The mechanistic investigation revealed the rapid formation of hydrazone upon the interaction of the probe with hydrazine via retro-Knoevenagel reaction as confirmed experimentally and corroborated with DFT calculations. The induced colorimetric and fluorometric changes were utilized in hydrazine sensing with excellent selectivity over other biologically relevant analytes with a detection limit of 0.76 µM in aqueous media. The practical utility of the probe was assessed in real-life natural water samples, while we have also developed a cost-effective portable kit for the on-site hydrazine detection both in the solution and vapor phases.

A Dicyanoisophorone-based Fluorescent Turn-on Probe for Rapid Detecting Thiophenol in Aqueous Medium and Living Cell Imaging

A novel colorimetric and fluorescent thiophenol probe based on dicyanoisophorone has been successfully achieved, which has low-cost, easy operation, high selectivity, sensitivity and stability. The chemosensor shows a large Stokes shift and approximately 170 nm when excited at 510 nm. ISO-DiNO2 could be utilized as “Turn-on” and a naked-eyes chemosensor to detect PhSH, which is accompanied by a distinct color shift from red to dark purple with strong red fluorescence at 365 nm UV-light. Its limit of detection was determined to be 1.15 μM. More importantly, ISO-DiNO2 can react instantaneously (<10 s) with PhS−. In addition, ISO-DiNO2 has been utilized in test paper strips, water sample together with imaging of PhS− in living Raw264.7 cells, demonstrating that ISO-DiNO2 has excellent and promising applications.

Colorimetric and fluorescent probes for cysteine detection: Applications in food safety and cellular imaging

In this study, three BODIPY-based fluorescent probes were designed and synthesized. The ultraviolet-visible spectra, fluorescence spectra, smartphone color recognition application and bioimaging were utilized to evaluate the capacity of the probes. By comparing key parameters, BDP-SIN had optimal performances including fastest response (10 min), highest signal-to-noise ratio (815 times) and lowest limit of detection (LOD = 49 nM). The recovery rate ranged from 92.04 % to 103.25 %. Meanwhile, BDP-SIN was triumphantly employed for determination of Cys in different daily food samples. Moreover, the test strips and microporous filter membrane loaded with BDP-SIN were developed for the portable real-time visualization and quantitative detection of Cys in food samples, which the contents ranged from 0.27 μM to 0.49 μM. Besides, BDP-SIN could image Cys in the living cells and mice. The novelty of this work was that developed an effective tool for researching the roles of Cys in food industry and living organisms.

Colorimetric pH-sensing of artificial gastric fluid using naphthalimide-based CH acids

In this study, we introduce novel colorimetric pH-sensing probes based on naphthalimide malonate derivatives. These probes were synthesized by reacting 4-bromo-1,8-naphthalimide with various malonates, including malononitrile, ethyl cyanoacetate, and diethyl malonate. Each derivative exhibited distinct pH-sensing characteristics due to their differing CH acidities. The malononitrile-based probe, NPI-N2, demonstrated pronounced chromogenic pH-signaling behavior, transitioning from colorless to red-violet, accompanied by a decrease in fluorescence intensity. Notably, NPI-N2 retained its pH-sensing capability in the presence of common metal ions, anions, and pepsin, a key component of gastric fluid. The pKa of NPI-N2 was determined to be 3.08 through pH-dependent absorbance curve fitting. To modulate the pH-sensing range, ester-nitrile (NPI-EN) and diethyl ester (NPI-E2) subunits were incorporated into the naphthalimide framework, resulting in increased pKa values of 6.73 and 10.76, respectively. The pH-signaling mechanism of NPI-N2 was elucidated by 1H and 13C NMR spectroscopy, revealing deprotonation of the malononitrile moiety and subsequent resonance extension through the naphthalimide structure. To facilitate practical pH determination, NPI-N2 was integrated into a paper-based test strip, enabling convenient and reliable pH measurement of artificial gastric fluid.

Biogenic PAG-FeNPs from Prunus armeniaca (Gum) as robust colorimetric sensors for methyl orange detection

Biogenic synthesis of nanoparticles is an emerging research area of the scientific community holding versatile and potential applications. The nanoscaled iron nanoparticles (FeNPs) have unique chemical and physical properties. Beside the available physical and chemical methods, the aqueous extract of the Prunus armeniaca Gum (PAG) was employed to promote a green and sustainable approach for the synthesis of FeNPs. The structure and morphology of the FeNPs were characterized by SEM, FTIR, and XRD techniques. And UV–Vis spectrophotometry is employed to study optical properties, time, temperature, and pH dependent stability. Herein PAG-FeNPs has been employed as efficient and cost-effective colorimetric probe for the sensing of methyl orange (MO) for the first time displaying a color change from light orange to dark voilet on exposure to MO. The selectivity of the detection method for MO against various interferences including heavy metals, and organic dyes was examined and sensor’s signal remained unaffected by common interferences. Under ideal detection conditions, the proposed method demonstrates an excellent linear correlation (R2 = 0.992) in the concentration range of 10–350 µM methyl orange. The limits of detection and limit of quantification are 13 µM and 40 µM, respectively. Moreover, the technique has been successfully employed for detecting methyl orange in self-contaminated tape water samples.

A turn-on anthraquinone-derived colorimetric and fluorometric dual-mode probe for highly selective Hg2+ determination and bioimaging in living organisms

Mercury ion (Hg2+) is considered a harmful neurotoxin, and real-time monitoring of Hg2+ concentrations in environmental and biological samples is critical. Fluorescent probes are a rapidly emerging visualization tool owing to their simple design and good selectivity. Herein, a novel fluorescence (FL) probe 2-(4-((6-((quinolin-8-yloxy)methyl)pyridin-2-yl)methyl)piperazin-1-yl)anthracene-9,10-dione (QPPA) is designed using piperazine as a linker between the anthraquinone group, which serves as a fluorophore, and N4O as the Hg2+ ligand. The probe exhibits FL “turn-on” sensing of Hg2+ because the complex inhibits the photo-induced electron transfer (PET) process. Moreover, QPPA can overcome the invasion by other possible cations, resulting in a clear color change from orange to colorless with the addition Hg2+. The chelation of QPPA with Hg2+ in a 1:1 ratio. Subsequently, the theoretically determined binding sites of the ligand to Hg2+ are validated through 1H NMR titration. The in situQPPA–Hg2+ complex can be subjected to Hg2+ extraction following the introduction of S2− owing to its robust binding capacity. The exceptional limit of detection values for Hg2+ and S2− are obtained as 63.0 and 79.1 nM (S/N = 3), respectively. Moreover, QPPA can display bright red FL in the presence of Hg2+ in different biological specimens such as HeLa cells, zebrafish, onion root tip tissues, and water flea Daphnia carinata, further providing an effective strategy for environmental monitoring and bioimaging of Hg2+ in living organisms.