Fluorescence Turn-on Strategy Research Articles

Sensitive and rapid detection of ciprofloxacin and ofloxacin in aqueous samples by a facile and green synthesized copper nanocluster as a turn-on fluorescent probe

The present method reports a rapid, inexpensive and sensitive sensing system based on fluorescence turn-on strategy for trace detection of ciprofloxacin (CIP) and ofloxacin (OFL) in aqueous samples. In a one pot method, copper nanocluster whose dimensions are less than 15 nm, were easily prepared and decorated with sodium gluconate (Gl@CuNCs) as a biocompatible material.The Gl@CuNCs were characterized with XRD, TEM, DLS, TG-DTA techniques as well UV–Vis, FT-IR and fluorescence spectroscopies.The maximum fluorescence emission of Gl@CuNCs at 414 nm with excitation at 322 nm shifted to higher wavelength upon addition of CIP and OFL. A good linear relationship between fluorescence emission and drug concentration was achieved in the concentration range of 0.005–0.3 μg mL−1 (15–900 nM for CIP and 14–830 nM for OFL). The limits of detection (LOD) for the determinations of CIP and OFL were calculated to be 9 and 8 nM, respectively. Furthermore, even a 100-fold higher concentration of interfering species had no significant effect on the detection of CIP and OFL. The proposed method was successfully used to determine CIP and OFL in drinking water, cow milk, human urine and serum samples with satisfactory recoveries.

Iron modified hydrogen-bonded organic framework as fluorescent sensor for ascorbic acid detection

Herein, iron modified hydrogen-bonded organic framework (Fe-HOF) was successfully prepared by introducing the yellow-green fluorescent ligand 2,5-dihydroxyterephthalic acid into HOF and then modifying Fe3+. A simple turn-on fluorescence strategy is proposed for the detection of ascorbic acid (AA) based on Fe-HOF. Fe3+ could effectively quench fluorescence emission of HOF. In the presence of AA, Fe3+ was reduced to Fe2+, which led to the fluorescence recovery of HOF, thus realizing the fluorescence quantitative detection of AA. These fluorescence responsive behaviors of Fe-HOF ensure fluorescence assay of AA within 0.5 − 8 μM, along with a limit of detection (LOD) of 0.14 μM. The sensing platform could realize the rapid detection of ascorbic acid in vitamin C pills, tablets and beverages in the detection of ascorbic acid with good recoveries.

Highly Selective and Portable Fluorescence Turn-On Detection of Sc3+ in Ore and Water Based on Strong Lewis Acid-Base Coordination.

Detecting scandium (Sc) with high selectivity and sensitivity is a challenging task due to its chemical similarity to other rare earth ions. Our findings show that the fluorescence of the complex fluorescent indicator calcein (CL) is quenched under acidic conditions (pH = 2), and Sc3+ strongly inhibits this process. The results demonstrate that CL forms multimers and precipitates out of the solution under acidic conditions, while Sc3+ causes a significant decrease in the scattering intensity of the solution. Additional experiments revealed that the strong Lewis acid nature of Sc3+ complexes with the carboxyl groups of CL leads to increased dispersion of CL even under acidic conditions, thus enhancing its absorption and fluorescence. The complexation ratio of Sc3+ and CL was investigated through spectral titrations and theoretical calculations. The interaction between Sc3+ and CL is the strongest among rare earth and common metal ions due to the smallest ionic radius, resulting in high selectivity. The fluorescence turn-on strategy had a linear range of 0.04 to 2.25 μM under optimal conditions, with a detection limit of 20 nM for Sc3+. The combination of 3D printing and a smartphone program allows for portable on-site analysis of Sc3+. Mineral and water samples were used to demonstrate the potential of this strategy for the rapid, selective, and sensitive analysis of low levels of Sc3+.

A turn-on fluorescence strategy for hypochlorous acid detection based on DNAzyme-assisted cyclic signal amplification

Hypochlorous acid (HClO) is a crucial active oxygen component and one of the innate immunity's barrier substances in the body. Abnormal fluctuations in HClO concentration can lead to increased oxidative stress, cellular dysfunction, and the onset of various diseases. Thus, developing convenient, affordable, efficient, and sensitive methods to monitor HClO concentration in healthcare and pathophysiology research is highly significant. In this study, we developed a novel fluorescence strategy for HClO detection based on nucleic acid oxidative cleavage and Pb2+-dependent DNAzyme. By introducing a phosphorothioate site in the hairpin-structured nucleic acid sequence, the nucleic acid probe specifically recognized HClO and underwent oxidative cleavage. Upon cleavage, the enzyme strand is liberated, forming DNAzyme. This DNAzyme then cleaves the substrate strand, liberating the initially quenched fluorescent dyes and generating a turn-on fluorescent signal. The enzyme strand produced by the oxidative cleavage of HClO can be repeatedly utilized, thus realizing the cyclic signal amplification to reduce background noise. We verified the detection mechanism of this strategy through stepwise fluorescence spectroscopy analysis and electrophoresis. Under optimal experimental conditions, the method achieved a detection limit of 5.38 nM and a linear range of 1 nM-800 nM. This method demonstrated exceptional performance in actual biological sample testing and presented an exciting opportunity for expanded utilization in clinical diagnosis and medical research.

Ce(IV)-coordinated organogel-based assay for on-site monitoring of propyl gallate with turn-on fluorescence signal

Propyl gallate (PG) is a commonly used synthetic phenolic antioxidant in foodstuffs and industrial products. Due to the potential health risk of PG, rapid and on-site detection in food and environment samples are important to guarantee human health. Herein, we demonstrated rapid monitoring of PG by a fluorescence turn-on strategy based on a specific fluorogenic reaction between PG and polyethyleneimine (PEI). Specifically, Ce4+ with oxidase-mimicking activity oxidized PG to its oxides, which then reacted with PEI through the Michael addition to generate the fluorescent compound. The proposed fluorogenic reaction had good specificity for PG, which could distinguish PG from other phenolic antioxidants and interferences. Furthermore, portable and low-cost organogel test kits were prepared using poly(ethylene glycol) diacrylate for quantitative and on-site detection of PG via a smartphone-based sensing platform. The organogel-based assay detection limit was 1.0 μg mL–1 with recoveries ranging from 80.2% to 106.2% in edible oils and surface water. Suitability of the developed assay was also validated by high-performance liquid chromatography. Our study provides an effective fluorescent approach to rapid, specific, and convenient monitoring of PG, which is useful for diminishing the risk of PG exposure.

Coal humus acid functionalized high stability fluorescent copper nanoclusters for tumor identification by sequential off-on-off monitoring tryptophan and Hg2.

The abnormalities of Tryptophan (Trp) and mercury ions (Hg2+) not only easily activate diseases, including mental illness and cancer, but also seriously affect human wellbeing. Fluorescent sensors are profoundly attractive options for identifying amino acids and ions; however, most sensors remain challenging due to the multipliable cost and deviation from the asynchronous quenching detection. In particular, fluorescent copper nanoclusters with high stability that quantitatively monitoring Trp and Hg2+ successively have seldom been reported. Herein, we employ coal humus acid (CHA) as a protective ligand and successfully construct weak cyan fluorescent copper nanoclusters (CHA-CuNCs) by a rapid, environmentally benign and cost-effective method. Significantly, the fluorescence of CHA-CuNCs is obviously improved by introducing Trp, because the indole group of Trp enhances the radiative recombination and aggregation-induced emissions. Interestingly, CHA-CuNCs not only realizes the highly selective and specific detection of Trp with a linear range of 25-200μM and a detection limit of 0.043μM based on the turn-on fluorescence strategy, but also quickly achieves the consecutive turn-off detection of Hg2+ due to the chelation interaction between Hg2+ and pyrrole heterocycle in Trp. Moreover, this method is successfully applied in the analysis of Trp and Hg2+ in real samples. Furthermore, the confocal fluorescent imaging of tumor cells demonstrates that CHA-CuNCs can be used for bioimaging and cancer cell recognition with Trp and Hg2+ abnormalities. These findings provide new guidance for the eco-friendly synthesis of CuNCs with eminent sequential off-on-off optical sensing property, indicating good prospects in biosensing and clinical medicine applications.

A fluorescence turn-on strategy to achieve detection of captopril based on Ag nanoclusters

In this work, a fluorescence method based on a turn-on strategy to achieve detection of captopril was established utilizing Ag nanoclusters(AgNCs). Captopril as the second ligand can protect AgNCs through the Ag-S bond, promoting electron transfer on the surface of nanoclusters and enhancing the fluorescence intensity of AgNCs. Therefore, a sensitive method to detect captopril was achieved, which shown a good linear range from 5 to 60 μM with low limit of detection (1.12 μM). The proposed fluorescence detection system was applied in practical serum samples, indicating satisfying recovery and providing a simple and sensitive strategy for detection of captopril.

Fluorescence turn-on Cu2-xSe@HA-rhodamine 6G FRET nanoprobe for hyaluronidase detection and imaging.

The application of nanostructures to design fluorescence resonance energy transfer (FRET) based sensing platforms has been greatly concerned with the demand for sensitive and selective detection of biomolecules. Here, a novel sensitive turn-on fluorescence strategy based on the FRET mechanism has been designed for hyaluronidase (HAase) detection through the modulation of Cu2-xSe@HA-Rh6G nanoprobe fabricated by self-assembly of rhodamine 6G (Rh6G) together with Cu2-xSe@HA nanoparticles through electrostatic adsorption. The Cu2-xSe@HA had extensive localized surface plasma resonance (LSPR) absorption in the wide range of ultraviolet (UV) to near-infrared (NIR) wavelengths and showed good light capture characteristics, which can be acted as good acceptors in the FRET interactions with Rh6G, inducing its efficient fluorescence quenching. In the presence of HAase, the FRET process was disrupted and the fluorescence signal was recovered. In the range of 0.1-10.0U/mL, the fluorescence recovery of Rh6G showed a good linear relationship with the concentration of HAase, and the detection limit was 0.06U/mL. The sensing platform has been used for HAase detection in real urine samples and cancer cells imaging.

Click reaction triggered turn-on fluorescence strategy for highly sensitive and selective determination of steroid hormones in food samples

The copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction has becoming noticeable in the field of analytical chemistry. Mild reaction conditions, simple operation, high efficiency, and good regioselectivity make this classical click reaction a perfect strategy for chemical derivatization. Herein, we proposed a promising click fluorescent labeling method with high selectivity for the determination of five steroid hormones in food samples. The labeling strategy depends on the reaction between 3-Azido-7-hydroxycoumarin and the alkynyl group of steroid hormones, which shows a turn-on fluorescence response in the presence of copper (I). The formed fluorescent products were detected by HPLC-FLD. Under the optimized conditions, the proposed method presented excellent performance with good linearity (R2 ≥ 0.9998) and low detection limit (1.8–7.3 μg L-1). Further, satisfactory recoveries were obtained to be 82–107% in spiked meats with relative standard deviations (RSDs) ≤ 5.7%. Finally, the established method was successfully applied for the determination of steroid hormones in meat, indicating the potential prospect of the click reaction in chemical derivatization.

Azine based fluorescent rapid "off-on" chemosensor for detecting Th4+ and Fe3+ ions and its real-time application

Biological toxicity and dangerous environmental pollution are inevitable when the level of Th4+ and Fe3+ exceeds the safety threshold. To address these problems, in this study, we report a dual-emission response chemosensor, HQCA, for rapid, sensitive, and selective detection of Th4+ and Fe3+ via colorimetric and fluorescence turn-on strategy. The absolute fluorescent "turn off" of HQCA, due to photoinduced electron transfer (PET), was immediately turned on with yellow fluorescence over the exposure to Th4+/Fe3+. The sensing capability of HQCA toward Th4+ and Fe3+ was studied in solution, and paper strips were fabricated with HQCA. Our results indicate excellent sensitivity and selectivity. Additionally, the value of emission intensity of HQCA had an excellent linear relationship with the concentration of Th4+/Fe3+, and the limit of detection (LOD) was found to be very low compared to reported methods and WHO norms. The interaction mechanism between HQCA and Th4+/Fe3+ was studied via Job's plot analysis, 1H NMR, Mass, and FT-IR analysis. Emission analysis of HQCA in the pH region 1–9 indicated that HQCA could successfully detect Th4+/Fe3+ in the pH region of 3–9. More importantly, the viability of HQCA to detect Th4+/Fe3+ ions were successfully tested in various water bodies and human serum albumin.

The contrastive study of two thiophene-derived symmetrical Schiff bases as fluorescence sensors for Ga3+ detection

Two thiophene-derived symmetrical Schiff bases R (N'2,N'5-bis((E)-2-hydroxybenzylidene)thiophene-2,5-dicarbohydrazide) and E (N'5,N'7-bis((E)-2-hydroxybenzylidene)-2,3-dihydrothieno[3,4-b][1,4]dioxine-5,7-dicarbohydrazide) were synthesized as sensors for Ga3+ detection via fluorescence turn-on strategy. After chelation with Ga3+, both of them displayed the significant fluorescence enhancement in MeCN/H2O buffer solution. Meanwhile, R and E showed ultralow detection limits of 3.90 × 10−9 M and 3.97 × 10−9 M, respectively. Differently, the sensor E featured much higher selectivity and anti-interference for Ga3+ detection than R in the presence of other cations such as In3+, Zn2+ and Cu2+. The Job’s plots revealed a 1:2 stoichiometry between sensors and Ga3+ with the association constant of 3.89 × 109 M2 for R and 8.59 × 109 M2 for E, respectively. To further explain the differences of sensing performance between the two sensors, the theoretical researches were executed through the molecular configuration, charge distribution, molecular orbitals, electronic transitions and energy variation. Besides, E could exhibit an efficient recognition of Ga3+ in the water samples.

A turn-on fluorescence sensor based on Cu2+ modulated DNA-templated silver nanoclusters for glyphosate detection and mechanism investigation

The abuse application of glyphosate can result in a potential hazard for environment and human, however its ultrasensitive detection remains challenging. Herein, a Cu2+ modulated DNA-templated silver nanoclusters (DNA-AgNCs) sensor was constructed to sensitively determine glyphosate based on the turn-on fluorescence strategy. The fluorescence quenching of DNA-AgNCs occurred with the existence of Cu2+. Upon the presence of glyphosate, the functional groups on the surface of glyphosate could chelate with Cu2+, following the fluorescence recovery of DNA-AgNCs. Through the stoichiometric methods, we unveil that Cu2+-trigged fluorescence quenching mode is a combination of static and dynamic quenching with the static mode being predominant. In DNA-AgNCs/Cu2+ system, the carboxylate, amine, and phosphonate groups of glyphosate interact with Cu2+ through chelation, in which the carboxylate oxygen, the phosphonate oxygen atoms, and the monoprotonated secondary amine nitrogen atom and Cu2+ form chelate rings. This fluorescence sensor showed a desired linearity of glyphosate analysis under the optimum conditions, ranging from 15 to 100 μg/L with a low detection down to 5 μg/L. Moreover, the proposed sensor was successfully utilized to measure glyphosate in real samples, indicating a promising application in pesticide residues detection.

Multichannel ratiometric fluorescence sensor arrays for rapid visual monitoring of epinephrine, norepinephrine, and levodopa

Catecholamines (CAs), as the important signal mediators in normal physiological processes, regulate many basic physiological functions in the body. However, it is hardly to rapidly distinguish different CAs molecules, such as dopamine, epinephrine (Ep), and norepinephrine (NE), because of their extremely similar molecular structures. Here, we, for the first time, propose a simple and fast fluorescence turn-on strategy to distinguish different CAs and their precursor levodopa (L-DOPA). Specifically, novel ratiometric fluorescent probes with high sensitivity and selectivity were constructed for the quantitative detection of Ep, NE, and L-DOPA, with the detection limits of 18.9, 85.5, and 9.7 nM, respectively. In addition, the suitability of these ratiometric fluorescent probes was validated by detection application of Ep, NE, and L-DOPA in real human serum and urine samples. Furthermore, a portable ratiometric fluorescent hydrogel sensing platform was prepared, with agarose chosen as the carrier for semi-quantitative on-site detection of Ep, NE and L-DOPA based on visual inspection with the naked eye. These results indicate that the developed detection strategy opens up a novel and exciting avenue for the rapid identification and clinical diagnosis of CAs.

A facile and highly efficient fluorescent turn-on switch strategy based on diketone isomerization and its application in peroxynitrite fluorescent imaging

• A facile and highly efficient fluorescence turn-on switch strategy based on the diketone isomerization was developed. • Peroxynitrite can selectively mediate this isomerization, and a selective probe of peroxynitrite was established. • The probe showed faster response time, lower detection limit and high selectivity toward peroxynitrite. • The probe was applied to the imaging of endogenously peroxynitrite in living cells. A fluorescence turn-on switch induced by functional group conversion offers great potential in fluorescent probes and bioimaging due to its high specificity and efficiency. Exploring novel fluorescence turn-on switches and their singling mechanism are of great significance. In this manuscript, a novel fluorescent turn-on switch strategy induced by diketone isomerization was reported. It was found that when the diketone group of the synthesized coumarin derivative was converted into its monoketone or carboxylic acid derivatives, it could be illuminated. With this fluorescence turn-on strategy, the obtained probe could be used as a trigger for peroxynitrite (ONOO − ). The imaging and monitoring of ONOO − in RAW 264.7 cells endogenously induced by acetaminophen and heat shock were successfully achieved. This diketone isomerization strategy will promote the design and construction of a series of novel redox probes.

Reversible Chemosensor for Bioimaging and Biosensing of Zn(II) and hpH in Cells, Larval Zebrafish, and Plants with Dual-Channel Fluorescence Signals.

Zinc/Zn(II) is an essential trace element for humans and acts as an important substance that maintains the normal growth, development, and metabolism of the body. Excess or deficient Zn(II) can cause abnormal metabolism in the human body, leading to a series of diseases. Moreover, biosystems have complex homeostasis systems, especially harsh pH (OH-) environments. Thus, investigating the variation in the levels of Zn(II) and OH- is extremely important in clinical, medical, and environmental testing. Nevertheless, the lack of practical and convenient fluorescence imaging tools limits the tracing of Zn(II) and OH- in biosystems. In this work, a well-designed dual-channel fluorescent signal response chemosensor (DACH-fhba) was assembled for selective sensing of Zn(II) and OH- in the biosystem using a fluorescence turn-on strategy. On encountering Zn(II), the chemosensor emitted a blue fluorescence signal (455 nm). Meanwhile, the bright green fluorescence signal (530 nm) increased with OH- addition simultaneously. With the blue/green dual fluorescence response of DACH-fhba, the sensor exhibited high stability and reversibility. Notably, the bioimaging revealed that DACH-fhba successfully tracked Zn(II) and OH- in live cells, larval zebrafish, and plants. Further results implied that DACH-fhba can be used to achieve visual detection of Zn(II) and OH- in organisms. Altogether, this work is conducive to the monitoring of Zn(II) and OH- in organisms and promotes the understanding of the function of Zn(II) and OH- in biosystems.

A turn-on upconversion fluorescence sensor for acrylamide in potato chips based on fluorescence resonance energy transfer and thiol-ene Michael addition

This study describes a turn-on upconversion fluorescence sensor for the detection of acrylamide (AA) based on glutathione (GSH) modulated turn-on fluorescence strategy. Polyethyleneimine-modified upconversion nanoparticles were first prepared by the hydrothermal method and then Rhodamine B derivative (RBD) was loaded on their surface through non-covalent bonding. The GSH coupled with RBD and strongly quenched the upconversion fluorescence via fluorescence resonance energy transfer. Upon addition of tris (2-carboxyethyl) phosphine, the thiol-ene Michael addition reaction between GSH and AA was efficiently catalyzed, resulted in the quenched fluorescence triggered on. Under the optimum conditions, a linear detection range from 0.1 to 104 μM was implemented for AA with a limit of detection of 0.68 nM and great sensitivity was observed. Importantly, the proposed sensor was evaluated for spiked potato chips samples with a satisfactory result in contrast to high-performance liquid chromatography, confirmed its applicability for the rapid detection of AA.

Copper nanoclusters as a turn-on fluorescent probe for sensitive and selective detection of quinolones

As a new type of fluorescent probe, metal nanoclusters have a broad application prospect in optical sensors and biosensors. In the present study, copper nanoclusters (CuNCs) have been synthesized by etching non-luminescent copper nanoparticles with excess cysteine (Cys). The as-prepared cysteine stabilized turquoise emitting copper nanocluster (Cys-CuNCs) exhibited strong fluorescence emission, and could be quenched by Fe3+ ions. After adding quinolones (QNs) to the quenching system, the fluorescence intensity of Cys-CuNCs was restored. A novel Cys-CuNCs-Fe3+ sensor for the detection of QNs, such as ofloxacin (OFL) and norfloxacin (NOR), was constructed based on the fluorescence turn-on strategy. The linear range of the proposed method is 0.5–40 μM for OFL and 0.5–50 μM for NOR, and the detection limits of OFL and NOR are all 50 nM. As a cost-effective, high selectivity and sensitivity sensor tool, the Cys-CuNCs-Fe3+ sensor had been successfully applied to detect QNs in tablets and human urine.

Fluorimetric detection of methylated DNA of Sept9 promoter by silver nanoclusters at intrastrand 6C-loop.

Methylation of DNA at carbon 5 of cytosines is the most common epigenetic modification of human genome. Due to its critical role in many normal cell processes such as growth and development, any aberrant methylation pattern in a particular locus may lead to abnormal functions and diseases such as cancer. Development of methods to detect methylation state of DNA which may eliminate labor-intensive chemical or enzymatic treatments has received considerable attention in recent years. Herein, we report a DNA methylation detection procedure based on fluorescence turn-on strategy. Target sequence was selected from Sept9 promoter region that has been reported as one of the most frequently methylated sites in colorectal cancer. Probe DNA was designed to be complementary to this sequence with an additional six cytosines in the middle to form an internal loop to host silver nanoclusters. The fluorescence intensity of the synthesized silver nanoclusters with the duplexes of probe-non-methylated target was significantly different from that of probe-methylated target. The fluorescence enhanced with increasing the methylated DNA concentration with a linear relation in the range of 1.0×10-8M to 5.0×10-7M with the detection limit of 8.2×10-9M, and quenched with non-methylated ones. The method was very specific in the presence of non-complementary sequences with maximum similarity of 40%. Circular dichroism spectra indicated that silver ions significantly affected the structure of methylated and non-methylated DNA into different extents which could further influence the nanocluster fluorescence. Finally, a method was introduced to meet the concerns in the applicability of the proposed method in real situation.

Functionalized reduced graphene oxide with aptamer macroarray for cancer cell capture and fluorescence detection.

Anintegrated aptamer macroarray functionalized with reduced graphene oxide (rGO) to specifically capture and sensitively detect cancer cellsis reported. The capture for cancer cells is based on effective recognition of the modified rGO surface through theaptamer against epithelial cell adhesion molecule (EpCAM). The rough structure of rGO enhances morphologic interactions between rGO film interface and the cancer cells, while super-hydrophilicity of modified rGO hinders nonspecific cell capture. The synergistic interactions offer the aptamer macroarray high efficiency of cancer cell capture. By means of a turn-on fluorescence strategy based on the conformation change of theaptamer induced by the target recognition, the enriched cancer cells can be directly read out at excitation/emission wavelengths of 550/680nm without washing, separation, and dying steps. The working range is1 × 102 to 2 × 104 cells per mL with a detection limit of 22 cells per mL. The results indicate that the aptamer macroarray has a considerable foreground for early diagnosis, therapy, and monitoring of cancer. Graphical abstract.

A novel dual-response chemosensor for bioimaging of Exogenous/Endogenous hypochlorite and hydrazine in living cells, Pseudomonas aeruginosa and zebrafish

Hypochlorite (ClO−) and hydrazine (N2H4) were poisonous to the biological environment. Accurate and sensitive identification of ClO− and N2H4 in biological and environmental systems was essential to reveal their various physiological and pathological functions. Herein, a dual-response chemosensor, HNTBA, was developed for quantitative monitoring and visualization of ClO− and N2H4in vitro and in vivo via fluorescence turn-on strategy. With the addition of ClO−/N2H4, fluorescence “OFF–ON” response was obtained for the sensor as a result of specific ClO−/N2H4-triggered CC bond cleavage reaction with converted to the corresponding aldehyde and hydrazone, which responding mechanism was verified by DFT calculation. Additionally, HNTBA features rapid response (<30 s) and low limit of detection (nanomole), high sensitivity and selectivity toward ClO−/N2H4 over other analytes, which allow it to be used for quantification of ClO−/N2H4 in a simulated physiological condition. Fluorescence imaging using HNTBA sensor was taken to monitor the exogenous/endogenous ClO− levels in hPDLCs and RAW 264.7 cells in a concentration-dependent manner. Notably, HNTBA exhibits high effectiveness for early assessment of the treatment response of ClO−-mediated in cells with N-acetylcysteine (NAC) and lipopolysaccharide (LPS). Moreover, HNTBA can be used to visualize N2H4 in live cells from blue channels with good performance. The outstanding sensing performances of HNTBA sensor enabled fast tracking of ClO− and N2H4 in Pseudomonas aeruginosa and zebrafish with fluorescence light up, and it could be further applied to a paper strip. The results demonstrate that HNTBA was a powerful tool to monitor ClO− and N2H4 in biosystems and environmental.