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As a polyphenolic compound, chlorogenic acid has antioxidant, anti-inflammatory, antiviral, anti-obesity and other effects. Based on the interactions between chlorogenic acid and the proteins (human serum albumin (HSA), pepsin (Pep), trypsin (Try), fat mass and obesity-associated protein (FTO)), results will provide clues for screening effective inhibitors. The interaction between chlorogenic acid and the four proteins (HSA, Pep, Try, FTO) was analyzed by the aid of fluorescence quenching, synchronous fluorescence, three-dimensional fluorescence, isothermal titration calorimetry, and molecular docking. It can be concluded that there is no obvious interaction between chlorogenic acid and FTO. The binding affinity between chlorogenic acid and three proteins is HSA Try Pep. The binding process is spontaneous, and the quenching type is static quenching. Hydrophobic interaction and hydrogen bonding is observed in the binding process. This study provides valuable information for understanding the interaction mechanism between chlorogenic acid and proteins, and provides clues for screening inhibitors.

The characteristics of the binding between quercitrin and HSA were investigated.

Studies have shown that the FTO gene is closely related to obesity and weight gain in humans. FTO is an N6-methyladenosine demethylase and is linked to an increased risk of obesity and a variety of diseases, such as acute myeloid leukemia, type 2 diabetes, breast cancer, glioblastoma and cervical squamous cell carcinoma. In light of the significant role of FTO, the development of small-molecule inhibitors targeting the FTO protein provides not only a powerful tool for grasping the active site of FTO but also a theoretical basis for the design and synthesis of drugs targeting the FTO protein. This review focuses on the structural characteristics of FTO inhibitors and discusses the occurrence of obesity and cancer caused by FTO gene overexpression.

The interactions between radicicol and four proteins (catalase, trypsin, pepsin, and human serum protein) are investigated by spectroscopic techniques and molecular docking. A static quenching process is confirmed. The binding constant value between radicicol and human serum protein is the largest among the four proteins. Results reveal changes in the micro-environment of the protein by the addition of radicicol. It is found that radicicol shows an inhibitory effect on the activity of proteins (catalase, trypsin, and pepsin). Molecular docking results are consistent with the thermodynamic experimental results. This work provides clues to the elucidation of the mechanisms of the interactions between radicicol and proteins.

In this work, it was first found that tectoridin can bind to the fat mass and obesity-associated protein (FTO) by isothermal titration calorimetry (ITC). Spontaneous exothermic reactions occurred between tectoridin and FTO driven by entropy. A static quenching mechanism was developed for this interaction by using the spectroscopic technique. Results of both ITC and fluorescence spectroscopy indicated that hydrophobic interactions are predominant in the formation of the complex. The binding parameters obtained from ITC are comparable to those obtained from fluorescence spectroscopy. The inhibition of tectoridin on the demethylase activity of FTO was confirmed by enzymatic activity assays. This study will provide the basis for the development of inhibitors for FTO demethylase.

This work designs a convenient method for fabrication of surface-enhanced Raman scattering (SERS) devices by loading gold nanostars (AuNSs) on a flat filter support with vacuum filtration. The dense accumulation of AuNSs results in a strong sensitization to SERS signal and shows sensitive response to gaseous metabolites of bacteria, which produces a SERS "nose" for rapid point-of-care monitoring of these metabolites. The "nose" shows good reproducibility and stability and can be used for SERS quantitation of a gaseous target with Raman signal. The impressive performance of the proposed SERS "nose" for detecting gaseous metabolites of common foodborne bacteria like

Studies have shown that the

(±)-Sodium5-bromo-2-(α-hydroxypentyl) benzoate (brand name: brozopine, BZP, 1a), derived from L-3-n-butylphthalide (L-NBP), has been reported to protect the brain from stoke and has been approved by CFDA in Phase I-II clinical trials. However, it remains to be investigated whether 1a may exhibit any cardioprotective effect on ischemia-reperfusion (I/R) injury. In the current study, C57BL/6 and ICR mice were pretreated with 1a, and myocardium I/R were then performed. We found that 1a not only significantly reduced the infarct size and improved cardiac contractile function after acute MI/R in both species, but also protected hearts from chronic MI-related cardiac injury. Mechanically, we found that 1a physically binds to 12/15-LOX-2 using molecular docking. The shRNA-mediated 12/15-LOX-2 knockdown almost completely blocked the protective effect of 1a. Our findings, for the first time, strongly indicate that 1a may serve as a potent and promising cardioprotective agent in treatment of I/R related injury, at least partially through targeting 12/15-LOX-2.

The traditional colony culture method for detection of pathogens is subjected to the laborious and tedious experimental procedure, which limits its application in point-of-care (POC) testing and quick diagnosis. This work designs an intelligent adhesive tape as a "three-in-one" platform for rapid sampling, photocontrolled release, and surface-enhanced Raman scattering (SERS) detection of pathogens from infected wounds. This tape is constructed by encapsulating densely packed gold nanostars as SERS substrates between two pieces of graphene and modified with a synthetic o-nitrobenzyl derivative molecule to form an artificial biointerface for highly efficient pathogen capture via electrostatic interaction. The captured targets can be conveniently released onto a solid culture medium by UV cleavage of o-nitrobenzyl moiety for pathogen growth and in situ SERS detection. As a proof of strategy, this "three-in-one" platform has been used for detecting the concurrent infection of Pseudomonas aeruginosa and Staphylococcus aureus by pasting the tape on a skin burn wound. The impressive detection performance with an analytical time of only several hours for these pathogens at an early growth stage demonstrates its great potential as a POC testing device for health care.

In this study, the interaction between 3-phenyl-1H-indazole (1a) and the fat mass and obesity-associated (FTO) protein was confirmed by isothermal titration calorimetry (ITC). The structure feature...

In this paper, we introduced a new strategy for converting aggregation-induced emission (AIE) to fluorescence emission in solution into the rational design of new fluorescent probes. Two fluorescent probes based on this strategy, namely, PDAM-Lyso and PDAM-Me, have been synthesized and tested both in vitro and in vivo. The fluorophores of the two probes are both phenothiazine molecules, which link to the diaminomaleonitrile (DAMN) moiety through imine bonds. In the presence of imine bonds, the probes emit red fluorescence in an aqueous solution caused by the AIE effect. As the imine bonds are selectively cut-off by HClO, the DAMN moiety gets removed, inducing blue fluorescence of the reaction product. In this way, the selectivity of the DAMN-based probes toward HClO against metal ions and other reactive oxygen species (ROS) was successfully improved. The imaging of endogenous and exogenous HClO with these two probes reveals that lysosome-targeting probes are of great advantage in the detection of natively generated HClO. Furthermore, the imaging of endogenous HClO in zebrafish suggests that PDAM-Lyso is capable of monitoring the generation of HClO in vivo, illustrating that this strategy is of great significance in designing new probes.

In this work, seven acrylonitrile derivatives were selected as potential inhibitors of fat and obesity-related proteins (FTO) by the aid of fluorescence spectroscopy, ultraviolet visible spectroscopy, molecular docking, and cytotoxicity methods. Results show that the interaction between 3-amino-2-(4-chlorophenyl)-3-phenylacrylonitrile (1a) and FTO was the strongest among these derivatives. Thermodynamic analysis and molecular modeling show that the main force between 1a and FTO is hydrophobic interaction. The cytotoxicity test showed that the IC50 value of 1a was 46.64 μmol/L, which indicated 1a had the smallest IC50 value and had the best inhibitory effect on the proliferation of leukemia K562 cells among the seven derivatives. Both our previous results and this work show that chlorine atoms play important role in the binding of small molecules and FTO. This work brings new information for the study of FTO inhibitors.

A colorimetric and ratiometric fluorescent probe PMN-TPP for imaging mitochondrial ClO

The interactions of human haemoglobin (HHb) with 5-epi-taiwaniaquinone G (G1) and one structural analogue of 5-epi-taiwaniaquinone G (G2) systematically by UV–vis absorption spectroscopy and fluore...

A novel pH-dependent two-photon fluorescent molecular probe ABMP has been prepared based on the fluorophore of 2, 4, 6-trisubstituted pyridine. The probe has an absorption wavelength at 354 nm and corresponding emission wavelength at 475 nm with the working pH range from 2.20 to 7.00, especially owning a good liner response from pH = 2.40 to pH = 4.00. ABMP also has excellent reversibility, photostability and selectivity which promotes its ability in analytical application. The probe can be excited with a two-photon fluorescence microscopy and the fluorescence cell imaging indicated that the probe can distinguish Hela cancer cells out of normal cells with a two-photon fluorescence microscopy which suggested its potential application in tumor cell detection.

Clenbuterol (CLB) is a notorious “lean meat essence”, which has harmful effects on human health. In this study, the binding of CLB to two proteins, human serum albumin (HSA) and the human fat mass and obesity associated protein (FTO), have been investigated by spectroscopic and molecular modeling methods. Fluorescence data revealed that CLB could bind to HSA (or FTO) to form a complex. Thermodynamic analysis and molecular modeling indicated that the binding process was a spontaneous molecular interaction procedure, in which hydrophobic interaction played a major role. Results indicated that CLB could lead to some microenvironmental changes of both proteins.

Two embedded sulfur atoms in a novel [2 + 2] Schiff-base macrocyclic dinuclear Zn(II) complex were found to be easily autoxidized to the sulfone units on air exposure, and the resultant sulfone-functionalized macrocyclic complex was obtained by the post-modification strategy exhibiting enhanced antimicrobial activities because of the presence of dual active sites in comparison with the sulfur-containing Schiff-base macrocycle.

The binding of two flavonols with fat mass and obesity-associated protein (FTO) was studied using fluorescence spectroscopy, Stern-Volmer kinetics, UV-Vis absorption, and molecular docking. The quenching of FTO fluorescence was determined to be static with binding constants on the order of 104 M−1. The interaction was studied over three temperatures, and the binding was found to be exothermic with a positive change in entropy. Thermodynamic analysis and molecular modeling suggest that hydrophobic interaction and hydrogen bonding interaction are the main binding force in stabilizing the flavonol–FTO complex.

Fluorescence imaging with tumor-specific fluorescent probe has emerged as a tool to aid surgeons in the identification and removal of tumor tissue. We report here a new lysosome-targeting fluorescent probe (NBOH) with BODIPY fluorephore to distinguish tumor tissue out of normal tissue based on different pH environment. The probe exhibited remarkable pH-dependent fluorescence behavior in a wide pH range from 3.0 to 11.0, especially a sensitive pH-dependent fluorescence change at pH range between 3.5 and 5.5, corresponding well to the acidic microenvironment of tumor cells, in aqueous solution. The response time of NBOH was extremely short and the photostability was proved to be good. Toxicity test and fluorescence cell imaging together with a sub-cellular localization study were carried out revealing its low biotoxicity and good cell membrane permeability. And NBOH was successfully applied to the imaging of tumor tissue in tumor-bearing mice suggesting potential application to surgery as a tumor-specific probe.

In this work, the binding of four hydroxyanthraquinones (HAQs) to fat mass and obesity-associated (FTO) protein has been studied using fluorescence, UV-vis absorption and circular dichroism spectroscopy as well as molecular docking analysis. Analysis of fluorescence data showed that the binding of HAQs to FTO occurred via a static quenching mechanism. Thermodynamic analysis and molecular docking results suggested that hydrophobic force played a major role in stabilising the HAQ-FTO complex. Circular dichroism spectra indicated that the secondary structure of FTO was changed by the addition of HAQs. Results also showed that emodin had the strongest quenching and binding ability among four HAQs.

In this work, the interaction between camptothecin (CPT) analogs and fat mass and obesity associated (FTO) was investigated using spectroscopy and molecular docking. From the experimental results, it was found that the CPT analogs caused the fluorescence quenching of FTO through a static quenching procedure. The binding constants and thermodynamic parameters at three different temperatures, the number of binding sites were obtained, which suggested that the hydrophobic interaction and electrostatic force played major role in the reaction between CPT analogs and FTO. Results revealed that 10-hydroxycamptothecin was the strongest quencher.

The fat mass and obesity-associated protein is a potential target for anti-obesity medicines. In the present work, the interaction between our synthesized 3-substituted 2-aminochromones and fat mass and obesity-associated protein were investigated using fluorescence spectroscopy, ultraviolet–visible spectroscopy and molecular modeling approach. Fluorescence spectroscopy showed that the fluorescence of fat mass and obesity-associated protein can be quenched by these compounds with a static quenching procedure. In addition, the thermodynamic parameters obtained from the fluorescence data showed that the hydrophobic force played a major role in stabilizing the complexes. Ultraviolet–visible spectroscopy, synchronous fluorescence spectroscopy and three-dimensional fluorescence spectroscopy indicated that these compounds can induce some conformational changes of fat mass and obesity-associated protein.

The alkaloids containing a carbazole nucleus are an established class of natural products with wide range of biological activities. A combination of thermodynamic and enzymatic activity studies provides an insight into the recognition of Clausine E by the fat mass and obesity-associated protein (FTO). The binding of Clausine E to FTO was driven by positive entropy and negative enthalpy changes. Results also indicated that the hydroxyl group was crucial for the binding of small molecules with FTO. The structural and thermodynamic information provides the basis for the design of more effective inhibitors for FTO demethylase activity.

Extracellular electron transfer (EET) plays a fundamental role in microbial reduction/oxidation of minerals. Extracellular polymeric substances (EPS) surrounding the cells constitute a matrix that separates the cell’s outer membrane from insoluble minerals and environmental fluid. This study investigated the effects of EPS on EET processes during microbial reduction of hematite by the iron-reducing strain Shewanella oneidensis MR-1 (MR-1). Electrochemical characterization techniques were employed to determine the influence of EPS components on the redox ability of MR-1. Cells with removed EPS exhibited approximately 30% higher hematite reduction than regular MR-1 cells, and produced a current density of 56 μA cm-2, corresponding to 3–4 fold that of regular MR-1. The superior EET of EPS-deprived cells could be attributed to direct contact between outer membrane proteins and hematite surface, as indicated by more redox peaks being detected by cyclic voltammetry and differential pulse voltammetry. The significantly reduced current density of MR-1 cells treated with proteinase K and deoxyribonuclease suggests that the electron transfer capacity across the EPS layer depends mainly on the spatial distribution of specific proteins and electron shuttles. Exopolysaccharides in EPS tend to inhibit electron transfer, however they also favor the attachment of cells onto hematite surfaces. Consistently, the charge transfer resistance of cells lacking EPS was only 116.3 Ω, approximately 44 times lower than that of regular cells (5,139.1 Ω). These findings point to a negative influence of EPS on EET processes for microbial reduction/oxidation of minerals.

In this paper, The binding of twelve 1,3-diazaheterocyclic compounds (1a-1 l) to the fat mass and obesity-associated (FTO) protein was investigated by fluorescence, UV-vis absorption spectroscopy and molecular modeling. Results indicated that the intrinsic fluorescence of FTO is quenched by the nine compounds (1a-1i) with a static quenching procedure. No interaction was observed between FTO protein and compounds (1j-1 l). The thermodynamic parameters obtained from the fluorescence data showed that the hydrophobic force played a major role in stabilizing the complex. The results of synchronous and three-dimensional fluorescence spectra showed that the conformation of FTO was changed. In addition, the influence of molecular structure on the quenching effect has been investigated.

In this work, we have synthesized five pyrazole derivatives (1a–1e). The interactions between fat mass and obesity-associated (FTO) protein and pyrazole derivatives have been investigated by fluorescence, synchronous fluorescence spectroscopy and UV–vis absorption. Results indicate that the intrinsic fluorescence of FTO can be quenched by the derivatives through a static quenching procedure. The binding constants and thermodynamic parameters at different temperatures were obtained. Thermodynamic results indicate that hydrophobic interaction forces play major role in the binding between 1a–1d and FTO. Pyrazole derivative 1e binds to FTO through van der Waals forces and hydrogen bonds. Results also show that 1e has the strongest quenching and binding ability among five pyrazole derivatives.

The interactions between human serum albumin (HSA) and 5-epi-taiwaniaquinone G (G2) or its isomeride (G1) was investigated by fluorescence, UV–visible absorption, resonance light scattering, synchronous fluorescence spectroscopy and 3D spectroscopy under mimic physiological conditions in combination with molecular modeling. The results revealed that G1 and G2 caused the fluorescence quenching of HSA by the formation of G1-HSA and G2-HSA complex, respectively. The binding constants and thermodynamic parameters at three different temperatures were obtained. Hydrophobic and electrostatic interactions played a role in the binding process of HSA and G1. Van der Waals force and hydrogen bond interaction played a role in the binding process of HSA and G2. Results showed that G2 was the stronger quencher and the position of methyl influenced the binding process between HSA and G1 (G2).

Fe(II) and α-ketoglutarate-dependent fat mass and obesity associated protein (FTO)-dependent demethylation of m⁶A is important for regulation of mRNA splicing and adipogenesis. Developing FTO-specific inhibitors can help probe the biology of FTO and unravel novel therapeutic targets for treatment of obesity or obesity-associated diseases. In the present paper, we have identified that 4-chloro-6-(6'-chloro-7'-hydroxy-2',4',4'-trimethyl-chroman-2'-yl)benzene-1,3-diol (CHTB) is an inhibitor of FTO. The crystal structure of CHTB complexed with human FTO reveals that the novel small molecule binds to FTO in a specific manner. The identification of the novel small molecule offers opportunities for further development of more selective and potent FTO inhibitors.

A new bithiazole-based ratiometric fluorescent chemosensor 4,4′-n-butyl-5,5′-(pyridin-4-yl)-2,2′-bithiazol (L) is prepared and its metal ion sensing properties have been investigated. It exhibits high sensitivity and selectivity toward Fe 3+ among a series of metal ions in EtOH: H 2 O (9:1, v/v). The probe displays a quick response for Fe 3+ over a broad pH range, and the presence of Fe 2+ can also be detected by adding an oxidant like Na 2 O 2 or H 2 O 2 . The association constant of resultant [FeL 2 ] cation is calculated to be 2.76 × 10 3 M −2 , and the detection limit for Fe 3+ is found to be 0.6 μM. The living cell and zebrafish imaging experiments demonstrate its value on the practical applications for biological systems.

In this work, nine 2-phenyl-1H-benzimidazole structural analogues were screened for potential inhibitor of the fat mass and obesity-associated protein (FTO) by isothermal titration calorimetry (ITC). The results show that the binding between 6-chloro-2-phenyl-1H-benzimidazole (1d) and FTO was dominated by entropy. Results of enzymatic activity assays provided an IC50 value of 24.65 μM for 1d. Our previous results and comparison of nine structural analogues indicated that the chlorine atom was crucial for the binding of small molecules with FTO. The identification of novel small molecules may provide information for the design of FTO inhibitors and the treatment of leukemia.

Nafamostat mesilate is a serine protease inhibitor and used for the treatment of pancreatitis and cancers. The fat mass and obesity-associated protein (FTO) was identified to be a demethylase and played an important role in physiological processes. The aim of this study was to examine the inhibition of Nafamostat mesilate on FTO demethylase activity. A combination of thermodynamic and enzymatic activity studies provides an insight into the recognition of Nafamostat mesilate by FTO. The binding of Nafamostat mesilate to FTO was driven by higher positive entropy changes and smaller negative enthalpy changes. The structural and thermodynamic information provides the basis for the design of more effective inhibitors for FTO. Our results might provide a novel target protein for Nafamostat mesilate.

The fat mass and obesity-associated protein (FTO), as an m6A demethylase, is involved in many human diseases. Virtual screening and similarity search in combination with bioactivity assay lead to the identification of the natural compound radicicol as a potent FTO inhibitor, which exhibits a dose-dependent inhibition of FTO demethylation activity with an IC50 value of 16.04 μM. Further ITC experiments show that the binding between radicicol and FTO was mainly entropy-driven. Crystal structure analysis reveals that radicicol adopts an L-shaped conformation in the FTO binding site and occupies the same position as N-CDPCB, a previously identified small molecular inhibitor of FTO. Unexpectedly, however, the 1,3-diol group conserved in radicicol and N-CDPCB assumes strikingly different orientations for interaction with FTO. The identification of radicicol as an FTO inhibitor and revelation of its recognition mechanism not only opens the possibility of developing new therapeutic strategies for treatment of leu...

Pseudomonas putida (P. putida) MnB1 is a widely used model strain in environment science and technology for determining microbial manganese oxidation. Numerous studies have demonstrated that the growth and metabolism of P. putida MnB1 are influenced by various environmental factors. In this study, we investigated the effects of hydrogen peroxide (H2O2) and manganese (Mn2+) on proliferation, Mn2+ acquisition, anti-oxidative system, and biofilm formation of P. putida MnB1. The related orthologs of 4 genes, mco, mntABC, sod, and bifA, were amplified from P. putida GB1 and their involvement were assayed, respectively. We found that P. putida MnB1 degraded H2O2, and quickly recovered for proliferation, but its intracellular oxidative stress state was maintained, with rapid biofilm formation after H2O2 depletion. The data from mco, mntABC, sod and bifA expression levels by qRT-PCR, elucidated a sensitivity toward bifA-mediated biofilm formation, in contrary to intracellular anti-oxidative system under H2O2 exposure. Meanwhile, Mn2+ ion supply inhibited biofilm formation of P. putida MnB1. The expression pattern of these genes showed that Mn2+ ion supply likely functioned to modulate biofilm formation rather than only acting as nutrient substrate for P. putida MnB1. Furthermore, blockade of BifA activity by GTP increased the formation and development of biofilms during H2O2 exposure, while converse response to Mn2+ ion supply was evident. These distinct cellular responses to H2O2 and Mn2+ provide insights on the common mechanism by which environmental microorganisms may be protected from exogenous factors. We postulate that BifA-mediated biofilm formation but not intracellular anti-oxidative system may be a primary protective strategy adopted by P. putida MnB1. These findings will highlight the understanding of microbial adaptation mechanisms to distinct environmental stresses.

Reactive oxygen species (ROS), especially HOCl/ClO−, have been demonstrated to play essential roles in both physiological and pathological processes, and an abnormal level of HOCl/ClO− is related to some diseases. In this work, a very fast responsive (within 30 seconds) porphyrin-based fluorescent probe, TPP-TCF, for ClO− with a NIR emissive wavelength was prepared. This probe exhibited excellent selectivity towards ClO− and would not be interfered with by other ROS and typical nucleophiles. The limit of detection (LOD) for ClO− was evaluated to be 0.29 μM, indicating high sensitivity towards ClO−. In further bioimaging experiments, TPP-TCF displayed low-cytotoxicity and good cell penetrability for recognizing exogenous ClO− in HeLa cells. Moreover, this probe was successfully applied in imaging endogenous ClO− in living animals.

The binding interaction of neutral red (NR) with bovine hemoglobin (BHb) was studied by fluorescence spectroscopy in combination with molecular modeling. NR quenched the intrinsic fluorescence of BHb via a static mechanism. According to relevant data, the binding constants were calculated at two different temperatures. The thermodynamic parameters obtained from the fluorescence data showed that the hydrophobic and electrostatic interactions played a major role in stabilizing the complex. Synchronous and three-dimensional fluorescence spectra of BHb were investigated in the presence of NR. The results showed that the environment of tryptophan and tyrosine residues was altered by the dye. The fluorescence experimental results were in agreement with the results obtained by molecular modeling study.

The fat mass and obesity associated protein (FTO) is a potential target for anti-obesity medicines. In this paper, we have synthesized two potential inhibitors for FTO, three-member-ring compound (W 3 ) and four-member-ring compound (W 4 ). The interactions of fat mass and obesity-associated (FTO) protein with W 3 (or W 4 ) have been studied by spectral method. Results show the intrinsic fluorescence is quenched by the W 3 (or W 4 ). The thermodynamics parameters indicate hydrophobic interaction play a major role in the interactions. The results of synchronous fluorescence spectra demonstrate that the microenvironments of Trp residue of FTO are disturbed by W 3 and W 4 . Results showed that W 3 are stronger quenchers and bind to FTO with the higher affinity than W 4 . The influence of molecular structure on the binding aspects has been investigated.

In this paper, we developed a new selectively fluorescent probe for Hg 2+ based on BODIPY. The probe exhibited strong affinity for Hg 2+ over other metal ions. Treatment with Hg 2+ would “turn on” the fluorescence of the probe, and strong green fluorescence could be observed. The binding constant ( K a ) of the probe with Hg 2+ was calculated to be 9.43 × 10 4 M −1 from a Benesi–Hildebrand plot and the detection limit was evaluated to be as low as 1.73 nM (LOD = 3 σ /slope, σ is standard deviation). Biological applications were investigated employing living HeLa cells, zebrafish and nude mouse.

A colorimetric and ratiometric fluorescent probe PMN–TPP for imaging mitochondrial ClO− was prepared. The selectivity of PMN–TPP was excellent and the detection would not be influenced by other ROS. The limit of detection (LOD = 3σ/slope) for ClO− was evaluated to be 0.43 μM, suggesting the probe's high sensitivity to ClO−. For the biological applications, PMN–TPP performed well in detecting endogenous HClO in living RAW264.7 macrophage cells. A co-localization study employing Mito Tracker green revealed that PMN–TPP was specifically located in the mitochondria of living RAW264.7 macrophage cells. In the in vivo experiment, a nude mouse with acute inflammation stimulated by lipopolysaccharide (LPS) was employed. After injection of PMN–TPP, the fluorescence signal changed gradually in 30 min and then remained unchanged in the injection region, demonstrating that PMN–TPP could detect the endogenous HClO in living animals.

Two novel and convenient methods for the determination of lincomycin (LCM) in aqueous solutions have been developed. The first method was based on the enhanced fluorescence of thioglycolic acidcapped CdTe quantum dots (TGA-CdTe QDs) by LCM. For the second method, the introduction of LCM could induce the aggregation of gold nanoparticles (AuNPs), displaying distinct changes in color and in UVvis spectra. Under optimal conditions, the enhanced fluorescence intensity was linearly proportional to LCM concentration in the range of 1–240 μg mL−1 with a detection limit of 2.63 × 10−1 μg mL−1. The second platform is capable of determining LCM in ranges from 1.00 × 10−3 to 2.00 × 10−2 μg mL−1 and from 3.00 × 10−2 to 1.20 × 10−1 μg mL−1 with a detection limit of 1.27 × 10−4 μg mL−1. Both methods were used for rapid detection of LCM in real samples with satisfactory results. Comparisons between the two methods were made.

A very fast-responsive fluorescent probe PZ-Py for imaging mitochondrial HClO/ClO(-), with a relatively long emission wavelength, was prepared. The limit of detection was evaluated to be 17.9 nM. Moreover, the probe PZ-Py was successfully applied in the imaging of endogenous HClO/ClO(-) in the mitochondria of RAW 264.7 cells and living nude mouse.

The interaction between cannabinol (CBN) and herring-sperm deoxyribonucleic acid was investigated by using acridine orange as a fluorescence probe in this work. UV-Vis spectroscopy, fluorescence spectroscopy, and DNA melting techniques were used. The fluorescence of DNA acridine orange was quenched by CBN. The results indicated that CBN can bind to DNA. The binding constant for the CBN and herring-sperm deoxyribonucleic acid was obtained at 3 temperatures, respectively. Results of molecular docking corroborated the experimental results obtained from spectroscopic investigations. The influence of ionic strength on the fluorescence properties was also investigated. The thermodynamic results indicated that hydrophobic interaction played a major role in the binding between CBN and DNA.