Perylene Probe Research Articles

Fluorescent detection of tartrazine based on the supramolecular self-assembly of cationic perylene diimide.

A cationic perylene probe was designed and synthesized for sensitive determination of tartrazine. In the presence of tartrazine, the fluorescence of theperylene probe was quenched by efficient supramolecular self-assembly of theperylene derivate. The quenching iscaused by the synergistic effect of noncovalent interactions including static electricity, π-π stacking, and hydrophobic interaction. Benefiting from these advantages, the probe exhibited excellent sensing performance to tartrazine within 2 min. The detection and quantification limit of tartrazine are as low as 2.42 and 8.07 nmol L-1, respectively, with a wide linear operation range from 15 to 500 nmol L-1. Most importantly, due to the high binding affinity (3.22 × 107 mol L-1) between the perylene probe and tartrazine, the sensing system shows great anti-interference capacity. Subsequently, the visualization application of the approach was evaluated by portable device, and the limits of detection for visual detection for test strip, membrane, and hydrogel were 0.5, 0.5, and 5 μmol L-1, respectively. Theapproach has been applied to monitor tartrazine in various food condiments with recoveries in the range 91.29-108.83%. As far as we know, this is the first report of using perylene-based probe for tartrazine determination, offering a promising strategy for the construction of perylene-based detection system in the field of food safety.

Smartphones and paper-assisted detection of TNP using a cationic perylene diimide derivative in 100% aqueous media

2,4,6-trinitrophenol (TNP) is an environmentally deleterious substance with high toxicity and explosibility. It is of great significance for environmental protection and public health to establish a rapidly on-site monitoring method for perilous TNP. Current methods for detecting TNP mainly rely on traditional laboratory analysis lacking rapid detection through intelligent modes. Herein, we construct a smartphone recognition based fluorescence sensing system via the supramolecular assembly of a perylene probe to quantify TNP. The sensing platform consists of a fluorescent probe based on quaternary ammonium functionalized perylene (PDI-BTMA), as the TNP-response recognition element, and smartphones as optical signals receptors bringing simpleness, celerity, and portability for TNP monitoring. The sensor reveals dual output signals of color and fluorescence in response to TNP. The results show that the optical responses of PDI-BTMA can be attributed to the formation of the supramolecular complex (PDI-BTMA/TNP) via non-covalent interactions including static electricity, hydrophobic interaction, charge transfer, and π-π stacking. It shows a wide linear range for TNP of 200–1200 nM with a detection limit of 9 nM. In addition, we successfully made portable PDI-BTMA fluorescence paper. The RGB value of fluorescence color was also collected by using the smartphone-assisted sensing platform, and the G/B channel values show a linear relationship with TNP concentration in 0.1–50 μM, with the lowest detection concentration of 48.4 nM. Additionally, it could be successfully utilized for quantitative TNP monitoring in environmental water and soil samples, which achieved a greater recovery rate in the range of 99–110%. This research integrating the PDI-BTMA probe with a smartphone firstly presents a new strategy for real-time and on-site monitoring of TNP in the environment.

Tumor Microenvironment Stimuli-Responsive Single-NIR-Laser Activated Synergistic Phototherapy for Hypoxic Cancer by Perylene Functionalized Dual-Targeted Upconversion Nanoparticles.

Although synergistic therapy has shown great promise for effective treatment of cancer, the unsatisfactory therapeutic efficacy of photothermal therapy/photodynamic therapy is resulted from the absorption wavelength mismatch, tumor hypoxia, photosensitizer leakage, and inability in intelligent on‐demand activation. Herein, based on the characteristics of tumor microenvironment (TME), such as the slight acidity, hypoxia, and overexpression of H2O2, a TME stimuli‐responsive and dual‐targeted composite nanoplatform (UCTTD‐PC4) is strategically explored by coating a tannic acid (TA)/Fe3+ nanofilm with good biocompatibility onto the upconversion nanoparticles in an ultrafast, green and simple way. The pH‐responsive feature of UCTTD‐PC4 remains stable during the blood circulation, while rapidly releases Fe3+ in the slightly acidic tumor cells, which results in catalyzing H2O2 to produce O2 and overcoming the tumor hypoxia. Notably, the emission spectrum of the UCTTD perfectly matches the absorption spectrum of the photosensitizer (perylene probe (PC4)) to achieve the enhanced therapeutic effect triggered by a single laser. This study provides a new strategy for the rational design and development of the safe and efficient single near‐infrared laser‐triggered synergistic treatment platform for hypoxic cancer under the guidance of multimodal imaging.

Polypeptide induced perylene probe excimer formation and its application in the noncovalent ratiometric detection of matrix metalloproteinase activity.

Matrix metalloproteinases (MMPs) are important biomarkers for a number of diseases. Thus, the precise determination of MMP activity is of crucial importance. Herein, we report a ratiometric fluorescence method for the sensitive and selective sensing of MMP activity. A number of positively charged MMP substrates (polypeptides) were designed and prepared. These polypeptides could induce aggregation of a negatively charged perylene diimide derivative (PC1). As a result, excimer fluorescence of PC1 was observed. Addition of the corresponding MMP resulted in cleavage of the polypeptide chain and dis-aggregation of PC1, which led to turning on of the PC1 monomer fluorescence. Based on the ratio of the monomer (545 nm, IM) and the excimer (680 nm, IM) fluorescence intensity changes, a ratiometric method I545/I680) was established to detect MMP activity. The enzymatic activity of a number of MMPs (MMP-1, 2, 3, 7, 9 and 13) could be determined with a limit of detection of 4.8, 2.2, 16, 6.0, 1.7 and 5.5 ng mL-1, respectively. Using MMP-2 and MMP-9 as examples, flavonoid herbal extracts as potential inhibitors were studied. It was observed that mangiferin, apigenin, quercetin and isoliquiritigenin had significant inhibiting effects on the enzyme activity. And these herbal extracts also inhibited tumor cell metastasis. Moreover, the developed strategy was also employed to determine the concentration of MMP-9 in human saliva samples. Since the method relies on only noncovalent interactions between the polypeptide and PC1, no covalent labeling of fluorescence dye on the polypeptide substrate is required, and the method is thus simple, broad-spectrum inexpensive and effective. It has the potential to be developed into a clinical test kit.

Protein discrimination based on DNA induced perylene probe self-assembly

The development of a simple and effective method for the highly sensitive and selective discrimination of proteins is a subject of enormous interest. Herein, we report the construction of a novel fluorescence detection method based on a perylene probe for the highly efficient discrimination of multiple proteins. Single-stranded DNA (ssDNA) could induce aggregation of the perylene probe which caused quenching of probe fluorescence. After the addition of a protein, the protein could interact with the ssDNA-probe assembly complex with “turn-on” or further “turn-off” fluorescence response. A sensor array was designed based on the above phenomena which could realize the successful discrimination of proteins with 100% accuracy of cross validation. Nine representative proteins were successfully recognized. Moreover, it was observed that a protein could induce characteristic effect on the DNA-probe assembly with varying pH of assay buffer. Thus, different proteins showed unique fluorescence response towards assay buffers having different pH values. The assay buffer pH was then utilized as a sensing channel. Based on Linear Discriminant Analysis (LDA) nine proteins were successfully discriminated at the nanomolar concentration with 100% accuracy of cross validation. Furthermore, the sensor array also demonstrated differentiation of the nine proteins regardless of their concentration. The developed sensor array could also detect the proteins with great precision in human urine sample at a quite low concentration, which suggests its practical applicability for analysis of biological fluids.

Identification of milk adulteration by a sensor array based on cationic polymer induced aggregation of a perylene probe

A novel fluorescence sensor array based on cationic polymer induced self-assembly of a perylene probe is developed. Cationic polymer induced aggregation of the carboxyl modified negatively charged perylene probe, and resulted in large quenching of monomer emission and generation of excimer emission. Upon the addition of negatively charged protein, monomer fluorescence restored with a decrease in excimer fluorescence. Based on these observations, we developed a six-channel sensor array to discriminate five main proteins in milk. In addition, we successfully identified pure milk out of different drinks using the developed sensor array since different drinks contained distinct species and contents of proteins. Furthermore, the sensor array exhibited excellent performance to discriminate milk adulterated by different concentrations of adulterants with 100% accuracy of cross validation. The analysis results also presented excellent linear correlation of adulterants contents and thus the developed sensor array shows great potential for quantitative detection of milk adulteration.

Label-free colorimetric aptasensor for rapid detection of aflatoxin B1 by utilizing cationic perylene probe and localized surface plasmon resonance of gold nanoparticles

A label-free colorimetric aptasensor for rapid detection of aflatoxin B1 (AFB1) has been developed using specific aptamer, cationic perylene probe (CPP), and unmodified citrate – stabilized AuNPs. In the absence of AFB1, the free specific aptamer forms complex structures with the CPP, resulting in the solution remaining red without aggregation of AuNPs. Conversely, in the presence of AFB1, the aptamer competes for interaction with AFB1 and CPP. Notably, the aptamer is strongly specific to AFB1, leading to CPP free in the solution. When unmodified citrate – stabilized AuNPs are supplemented, the color turns blue as a result of AuNPs aggregation induced by CPP. The color change of AuNPs comes from localized surface plasmon resonance absorption, which relates to the size, shape, and agglomeration of the nanoparticles. This phenomenon can be measured through colorimetric detection. In this work, we presented two approaches, i.e., by using a spectrophotometer and a homemade colorimeter as a detector, which provided the limit of detections of 0.36 and 0.18 ng/mL, respectively. The application for the determination of AFB1 in rice and peanut samples was carried out. The proposed colorimetric aptasensor offers advantages in terms of simplicity, rapid detection, and high selectivity. Furthermore, the sensitivity for the real application is practical when coupled with an affinity column as sample preparation.

A fluorescence sensor array based on perylene probe monomer-excimer emission transition for the highly efficient differential sensing of metal ions and drinking waters

A new type of sensor array is developed for the highly efficient differential sensing of metal ions and drinking waters. Two functionalized fluorescent perylene probes (Pery-1 and Pery-2) were employed. These probes could interact with metal ions via electrostatic and coordinate bonding interactions. As a result, the probe monomer fluorescence was quenched, and the appearance of distinct excimer emission was observed. Depending on the metal ion used, various degrees of quenching of probe monomer fluorescence, and the generation of excimer emission were observed. For example, quenching of monomer fluorescence was observed when Cu2+ and Fe3+ ions were tested. However, quenching of monomer fluorescence and generation of excimer fluorescence were both observed when Pb2+, Zn2+ and Al3+ ions were employed. And it was also observed that Ni2+, Mn2+ and Cr3+ ions interacted differently with Pery-1 and Pery-2. These differences formed the basis of the metal ion sensor array. The sensor array was used for differentiation of eleven metal ions, and it was also capable of discrimination of metal ions at different concentrations, as well as the discrimination of metal ion mixtures. The array was further successfully used for the distinction of drinking waters, different brands of commercial mineral water, and evaluation of the quality of drinking water. We envisage that the monomer and excimer emission transition of the perylene probe could be easily adopted for efficient sensor array development for various sensing applications.

Novel perylene probe-encapsulated metal–organic framework nanocomposites for ratiometric fluorescence detection of ATP

Adenosine triphosphate (ATP) plays an important role in various biological processes and the ATP level is closely associated with many diseases. Herein, a novel ratiometric fluorescence assay for ATP was developed based on the excimer-monomer transfer of a perylene probe. By encapsulating a perylene probe, N,N'-bis(6-caproic acid)-3,4:9,10-perylenediimide (PDI), into zeolitic imidazolate framework-8 (ZIF-8) nanocrystals, fluorescent nanocomposites (PDI@ZIF-8) with significant excimer emission of the perylene probe were prepared for the first time. The presence of ATP will trigger the decomposition of PDI@ZIF-8 due to much stronger coordination between ATP and Zn2+ than that of 2-methylimidazole and Zn2+. As a result, the encapsulated PDI probes were released, leading to significantly increased monomer emission accompanying the decrease in the excimer emission. The excimer-monomer transition signal was utilized for ratiometric ATP sensing and its potential application for detecting ATP in cell lysates was also successfully demonstrated.

Surfactant and alcohol induced disaggregation of perylene probes and a novel sensing strategy for distinguishing the brand and authenticity of makeup removers

A novel sensing strategy based on four perylene probes to distinguish the brand and authenticity of makeup removers.

A perylene monoimide probe based fluorescent micelle sensor for the selective and sensitive detection of picric acid.

A hydroxyl functionalized perylene monoimide probe (PMI-OH) was prepared and self-assembled with the nonionic surfactant Triton X-100 (TX100) to fabricate a fluorescent micelle sensor for the selective and sensitive detection of picric acid (PA), a common explosive and environmental pollutant. The synthesized PMI-OH probe exhibited excimer fluorescence emission, and the intensity of the excimer fluorescence emission was significantly enhanced after the PMI-OH probe formed micelles with TX100. The obtained PMI-OH@TX100 micelles presented excellent photoluminescence properties and had a maximum fluorescence emission at 630 nm. The red fluorescence of the PMI-OH@TX100 micelles was quenched upon introduction of the nitro explosive PA due to electron transfer from the donor (PMI-OH) to the acceptor (PA). The fluorescence quenching of the fluorescent micelle sensor was proportional to the concentration of PA in the range of 2 to 10 μM. The limit of detection was 500 nM using 3σ/k. Thus, the developed PMI-OH@TX100 micelle sensor has great potential to detect PA in ordinary samples.

Ratiometric fluorescence sensors for heparin and heparinase based on enhanced excimer emission of perylene probe induced by cationic silver nanoparticles

Herein, cationic MUTAB-Ag NPs of different sizes were synthesized and their interactions with a negatively charged perylene probe, N,N′-bis(6-caproic acid)-3,4:9,10-perylenediimide (PDI-COOH), were investigated. MUTAB-Ag NPs could result in significant monomer quenching and excimer formation by inducing probe aggregation due to the strong electrostatic attractive interactions between them. Moreover, significant excimer emission could be observed at extremely low probe concentration when induced by larger MUTAB-Ag NPs. A possible mechanism of metal-enhanced fluorescence was proposed, which is evidenced by the strong dependence between surface plasmon resonance absorption spectra of MUTAB-Ag NPs and the excimer emission spectra of PDI-COOH, together with the sharp decrease in fluorescence lifetime of excimer compared with that induced by poly(allylamine). Consequently, ratiometric fluorescence sensors for heparin and heparinase were developed based on the Ag NP-induced excimer emission of PDI-COOH. The adsorption of heparin on the surface of MUTAB-Ag NPs led to the release of monomer, while the degradation of heparin by heparinase facilitated the formation of PDI-COOH excimer. The monomer-excimer transition signal was harnessed for heparin and heparinase sensing, which exhibited good sensitivity and excellent selectivity. Finally, application of the present system for detection of heparin and heparinase in human serum sample was successfully demonstrated.

Highly sensitive aflatoxin B1 sensor based on DNA-guided assembly of fluorescent probe and TdT-assisted DNA polymerization

A novel aptasensor, based on a perylene probe (PAPDI; N,N′-bis(propylenetrimethylammonium)-3,4,9,10-perylenediimide), was developed for the detection of aflatoxin B1 (AFB1) in maize samples. AuNPs/DNA composites were synthesized and integrated with aptamers-modified magnetic nanoparticles (MNPs) via DNA hybridization. For AFB1 determination, AuNPs/DNA composites were released from MNPs through specific binding of AFB1 with the aptamer and used for assembly of the PAPDI probe. To enhance the method sensitivity, terminal deoxynucleotidyl transferase (TdT)-catalyzed DNA polymerization was performed to elongate DNA on AuNPs/DNA composites. As a result, more PAPDI probes were assembled on the AuNPs/DNA composites. Through a multiple signal amplification strategy, the proposed method exhibited high sensitivity towards AFB1, with a detection limit of 0.01 nM (3.1 pg/mL). In summary, the proposed method has great potential to be a universal strategy for monitoring AFB1 in food samples.

EPR Spectroscopic and Thermal Analysis Study of Spent NiMo/WO3–Al2O3 Catalysts for Hydrodeoxygenation of Vegetable Oil

This paper presents the results of an electron paramagnetic resonance (EPR) and thermal analysis (TGA, DTA) study of a series of bifunctional NiMo/WO3–Al2O3 catalysts containing 0 to 30 wt % WO3 modifier before and after testing them in the process of hydrodeoxygenation of vegetable oil. The dependence of the content of carbonaceous deposits in the spent samples (according to EPR and TGA) on the concentration of acid sites as determined by EPR of perylene probe molecules in the initial catalysts is determined. Deactivation is explained by the participation of medium- and weak-strength Bronsted acid sites in the condensation of the initial unsaturated hydrocarbon molecules and their intermediates leading to the formation of various forms of coke precursors.

Black phosphorus nanosheets based sensitive protease detection and inhibitor screening

Proteases, as one of the most significant kind of digestive enzymes, are closely related to a variety of physiological processes and diseases. Herein, a black phosphorus nanosheets (BPs) based sensitive fluorometric method for protease detection and inhibitor screening is proposed. The aqueous solution of perylene probe (probe 1) displays a strong fluorescence. BPs, as novel discovered two-dimensional (2D) materials, can adsorb probe 1 through electrostatic interactions, which causes fluorescence quenching of probe 1. Histone can control the interactions between the perylene probe and BPs, which can be further regulated by the introduction of a protease. Thus, the protease activity can be monitored by detecting the fluorescence intensity changes of probe 1. The method is label free, sensitive and selective. As low as 1 ng/mL trypsin can be easily detected.

Metal coordination polymer induced perylene probe excimer fluorescence and its application in acetylcholinesterase sensing and alpha-fetoprotein immunoassay.

A novel sensing strategy for acetylcholinesterase (AChE) and alpha-fetoprotein (AFP) is developed, based on the perylene probe monomer to excimer fluorescence transformation induced by the in situ generation of a metal coordination polymer. In the presence of AChE, acetylthiocholine chloride was hydrolyzed to thiocholine. Ag+ and the produced thiocholine formed a positively charged metal coordination polymer, which induced the aggregation of a negatively charged perylene probe and the formation of probe excimer emission. The intensity ratio of excimer to monomer emission was proportional to the AChE concentration. A sensing method for AChE was thus established with a detection limit of 0.02 mU mL-1. The excimer emission with a large Stokes shift could avoid the interference of background fluorescence from complex biological samples, and thus achieved selective and sensitive detection of AChE. In addition, a fluorescence immunoassay strategy for AFP was then developed. Gold nanoparticles (AuNPs) co-immobilized with acetylcholinesterase and the AFP antibody as the capture and amplification probe were first prepared. In the presence of AFP, the sandwich structure was formed by immunological recognition. The hydrolysis of acetylthiocholine was catalyzed by AChE on the AuNPs, and the metal coordination polymer was then formed which resulted in the aggregation of the perylene probe and the formation of the excimer emission. The proposed sensing method offers a new strategy for the detection of other biomarkers.

A smart perylene derived photosensitizer for lysosome-targeted and self-assessed photodynamic therapy

A perylene probe PC4 is explored as a smart lysosome-targeted photosensitizer. It can efficiently kill cancer cells and also mark dead cells with bright fluorescence emission in nuclei for real-time monitoring and assessing of the photodynamic therapeutic efficiency.

A perylene-based membrane intercalating conjugated oligoelectrolyte with efficient photodynamic antimicrobial activity.

A perylene probe PC4 is exploited as a membrane intercalating conjugated oligoelectrolyte for efficient antimicrobial photodynamic therapy. PC4 can also serve as a fluorescent microbial cell death marker.

A real-time fluorescence assay for protease activity and inhibitor screening based on the aggregation-caused quenching of a perylene probe.

We have established a real-time and label-free fluorescence turn-on strategy for protease activity detection and inhibitor screening via peptide-induced aggregation-caused quenching of a perylene probe. Because of electrostatic interactions and high hydrophilicity, poly-l-glutamic acid sodium salt (PGA; a negatively charged peptide) could induce aggregation of a positively charged perylene probe (probe 1) and the monomer fluorescence of probe 1 was effectively quenched. After a protease was added, PGA was enzymatically hydrolyzed into small fragments and probe 1 disaggregated. The fluorescence recovery of probe 1 was found to be proportional to the concentration of protease in the range from 0 to 1mU/ml. The detection limit was down to 0.1mU/ml. In the presence of a protease inhibitor, protease activity was inhibited and fluorescence recovery reduced. Moreover, we demonstrated the potential application of our method in a complex mixture sample including 1% human serum. Our method is simple, fast and cost effective.

A label free Ag+ sensing method via in situ formation of metal coordination polymer

Metal ions sensing play critical roles in environmental monitoring and in biology. In this assay, we report the development of a facile fluorometric method for the sensing of Ag+ ions via the in situ formation of metal coordination polymer, based on the selective interactions of GSH with Ag+. The formation of coordination polymer with net multiple negative charges in an aqueous buffer solution (Tris-HAc, pH 9.0) resulted in aggregation and fluorescence quenching of a cationic perylene probe. The difference in emission intensity spurred us to develop a new strategy for sensing Ag+ ions. The proposed Ag+ detection method is simple, convenient, selective and sensitive, and can be used for Ag+ detection in lake water samples.