Fluorescence Resonance Energy Transfer Process Research Articles

A Core-Shell-Satellite Structured Fe3 O4 @g-C3 N4 -UCNPs-PEG for T1 /T2 -Weighted Dual-Modal MRI-Guided Photodynamic Therapy.

Reactive oxygen species (ROS) produced in the specific tumor site plays the key role in photodynamic therapy (PDT). Herein, a multifunctional nanoplatform is designed by absorbing ultrasmall upconversion nanoparticles (UCNPs) on mesoporous graphitic-phase carbon nitride (g-C3 N4 ) coated superparamagnetic iron oxide nanospheres, then further modified with polyethylene glycol (PEG)molecules (abbreviated as Fe3 O4 @g-C3 N4 -UCNPs-PEG). The inert g-C3 N4 layer between Fe3 O4 core and outer UCNPs can substantially depress the quenching effect of Fe3 O4 on the upconversion emission. Upon near-infrared (NIR) laser irradiation, the UCNPs convert the energy to the photosensitizer (g-C3 N4 layer) through fluorescence resonance energy transfer process, thus producing a vast amount of ROS. In vitro experiment exhibits an obvious NIR-triggered cell inhibition due to the cellular uptake of nanoparticles and the effective PDT efficacy. Notably, this platform is responsive to magnetic field, which enables targeted delivery under the guidance of an external magnetic field and supervises the therapeutic effect by T1 /T2 -weighted dual-modal magnetic resonance imaging. Moreover, in vivo therapeutic effect reveals that the magnetism guided accumulation of Fe3 O4 @g-C3 N4 -UCNPs-PEG can almost trigger a complete tumor inhibition without any perceived side effects. The experiments emphasize that the excellent prospect of Fe3 O4 @g-C3 N4 -UCNPs-PEG as a magnetic targeted platform for PDT application.

Ratiometric sensing of Fe3+ through PET-CHEF-FRET processes: Live cell imaging, speciation and DFT studies

4-Hydroxy-5-isopropyl-2-methylisophthalaldehyde anchored rhodamine B derivative, RDDFT experiences Fe3+ assisted inhibition of photoinduced electron transfer (PET), chelation-enhanced fluorescence (CHEF) and fluorescence resonance energy transfer (FRET) process in aqueous buffered acetonitrile media. RDDFT is an excellent colorimetric Fe3+ probe that undergoes ratiometric fluorescence change to recognize and determine traces of Fe3+ in presence of Fe2+ in real sample, thus allowing speciation studies of iron. It detects as low as 2×10−8M Fe3+ with an association constant, 3.7025×106M−1. Common ions do not show any significant interference in the detection of Fe3+ ion. RDDFT efficiently images intracellular Fe3+ in HeLa cells under fluorescence microscope. DFT studies strongly support experimental findings.

A fluorescent sensing for glycoproteins based on the FRET between quantum dots and Au nanoparticles

A simple fluorescent probe based on fluorescence resonance energy transfer (FRET) between the glucosamine-Mn-doped ZnS QDs and mercaptophenylboronic acid (MBA)-capped AuNPs was designed for the determination of glycoproteins such as immunoglobulin G (IgG), transferrin (Trf), α1-acid glycoprotein (AGP) and horseradish peroxidase (HRP). The FRET process took place via interaction between the glucosamine on the surface of QDs and boronic acid moieties on AuNPs surface, and resulted in the fluorescence quenched of the QDs. The FRET efficiency from QDs to AuNPs was calculated to be 75.4%. However, the FRET process would be inhibited after glycoproteins were introduced into the QDs-AuNPs system. The stronger interaction between the MBA on the surface of AuNPs and glycoproteins would keep the AuNPs far away from the QDs surface, leading to the fluorescence recovered of the QDs. The as-prepared sensor showed a high sensitivity and selectivity for glycoproteins. The dissociation constants and the detection limits of the selected standard glycoproteins (Trf, HRP, IgG and AGP) were estimated to be around 10−7M and 10−9M, respectively. Finally, this sensor has been successfully used for the determination of the AGP in serum samples without any complicated pretreatment and the recovery was in the range of 70%–105%.

Interpreting the effect of confined cyclodextrin media on the FRET efficacy between Naproxen and a bio-active 3-pyrazolyl-2-pyrazoline derivative on the light of spectroscopic investigation appended by TD-DFT simulations and molecular docking analysis

Abstract Significant Fluorescence Resonance Energy Transfer (FRET) process was observed between Naproxen (NPX) and a pharmaceutically important 3-pyrazolyl-2-pyrazoline derivative (PYZ) in bulk aqueous and heterogeneous cyclodextrin medium. The FRET efficacy of NPX-PYZ pair varied considerably in different cyclodextrin environments. Variation in the FRET efficacy mainly occurs due to a change in microenvironment of the fluorophores from bulk to a confined one. The structures of the FRET-pair and their interactions with cyclodextrins invoke a change in their spatial arrangement and proximity, which noticeably affects the FRET efficacy. The plausible explanations for this modulation in FRET efficacy has been established by employing steady state and time resolved fluorescence techniques in which simultaneous time–correlated analysis of the donor decay was observed to be reduced through FRET rather than some other relaxation pathway. Molecular Docking Analysis provided evidence of the possible modes of spatial orientation of the FRET pair in different cyclodextrin nano-cavities. Further TD-DFT calculations using B3LYP/6-31G/(d,p) method provided an intriguing insight about the medium dependent changes in the energies of the frontier molecular orbitals (HOMO-LUMO) associated with the corresponding FRET pair.

Molecularly imprinted magnetic microparticles for the simultaneous detection and extraction of Rhodamine B

Core–shell magnetic silica nanoparticles coated by molecularly imprinted polymer (Fe3O4@SiO2@MIP, M-MIP) accompanied with fluorescence resonance energy transfer (FRET) responsivity have been successfully prepared for simultaneous selective detection and extraction of trace organic dye, Rhodamine B (RhB). The M-MIP showed the advantage of rapid mass transfer and binding kinetics and significant selectivity for RhB molecules with a maximum adsorption capacity of 29.64mg/g. Notably, RhB, the template molecule acted as the acceptor, while the nitrobenzoxadiazole (NBD−) fluorophores containing in the MIP layer of M-MIP, introduced by the functional monomer molecules, acted as the donor in FRET process, which could be used to detect trace RhB base on the change of fluorescence signal. The simultaneous sensitive detection and selective extraction for RhB and easy magnetic separation of M-MIP indicated that the core–shell M-MIPs had the potential to be a kind of good sensor and adsorbent for specific dye in the application of food safety and environmental science.

Fluorescent “on-off-on” switching sensor based on CdTe quantum dots coupled with multiwalled carbon nanotubes@graphene oxide nanoribbons for simultaneous monitoring of dual foreign DNAs in transgenic soybean

With the increasing concern of potential health and environmental risk, it is essential to develop reliable methods for transgenic soybean detection. Herein, a simple, sensitive and selective assay was constructed based on homogeneous fluorescence resonance energy transfer (FRET) between CdTe quantum dots (QDs) and multiwalled carbon nanotubes@graphene oxide nanoribbons (MWCNTs@GONRs) to form the fluorescent “on-off-on” switching for simultaneous monitoring dual target DNAs of promoter cauliflower mosaic virus 35s (P35s) and terminator nopaline synthase (TNOS) from transgenic soybean. The capture DNAs were immobilized with corresponding QDs to obtain strong fluorescent signals (turning on). The strong π–π stacking interaction between single-stranded DNA (ssDNA) probes and MWCNTs@GONRs led to minimal background fluorescence due to the FRET process (turning off). The targets of P35s and TNOS were recognized by dual fluorescent probes to form double-stranded DNA (dsDNA) through the specific hybridization between target DNAs and ssDNA probes. And the dsDNA were released from the surface of MWCNTs@GONRs, which leaded the dual fluorescent probes to generate the strong fluorescent emissions (turning on). Therefore, this proposed homogeneous assay can be achieved to detect P35s and TNOS simultaneously by monitoring the relevant fluorescent emissions. Moreover, this assay can distinguish complementary and mismatched nucleic acid sequences with high sensitivity. The constructed approach has the potential to be a tool for daily detection of genetically modified organism with the merits of feasibility and reliability.

A novel fluorescent turn-on biosensor based on QDs@GSH-GO fluorescence resonance energy transfer for sensitive glutathione S-transferase sensing and cellular imaging.

A novel fluorescent turn-on biosensor based on fluorescence resonance energy transfer (FRET) from GSH functionalized Mn-doped ZnS QDs to graphene oxide (GO) was constructed to determine glutathione S-transferases (GSTs) in live cells and human urine. The QDs@GSH is adsorbed on the GO surface via hydrogen bonding interaction between the GSH on the surface of QDs@GSH and GO, and as a result, fluorescence quenching of the QDs@GSH takes place because of FRET. The FRET efficiency from QDs@GSH to GO was calculated to be 86.3%. However, in the presence of GSTs, the FRET process could be inhibited by the specific interaction between the GSH on the surface of QDs@GSH and GSTs, which would keep the QDs@GSH far away from the GO surface, leading to the recovery of the fluorescence. The proposed sensor exhibited high sensitivity, selectivity, and excellent specificity in the buffer, live cells and human urine for the detection of GSTs. Under the physiological conditions (pH 7.4), dissociation constants and the detection limit of GST and ATP6 V1F (a GST-tagged protein) were estimated to be 8.0 × 10-9 M, 2.1 × 10-10 M and 3.5 × 10-9 M, 7.2 × 10-11 M, respectively. The presented method has been successfully utilized for the determination of the GSTs in live cells and human urine without any complicated pretreatment and the recovery was in the range of 80%-90%.

Lanthanide-doped bismuth oxobromide nanosheets for self-activated photodynamic therapy.

Low tissue penetration depth of the excited light and complicated synthetic procedures greatly hinder the clinical application of photodynamic therapy (PDT). Here we present a facile and mass production route to fabricate Yb3+/Tm3+ co-doped BiOBr nanosheets. In contrast to the complicated combination of photosensitizers (PSs) with up-conversion nanoparticles (UCNPs), which generates a PDT effect by a fluorescence resonance energy transfer process from UCNPs to PSs upon near-infrared light excitation, this as-synthesized material can be self-activated by deep-penetrating 980 nm laser light to produce a large amount of reactive oxygen species, giving rise to a high PDT efficiency which has been proven by in vitro and in vivo therapeutic assays. Surface modification of the BiOBr:Yb,Tm nanosheets with polyethylene glycol endows the system with improved biocompatibility. Through the combination of inherent fluorescence and CT imaging properties, an imaging-monitored therapeutic system has been realized. The system overcomes the problems of low tissue penetration depth, complicated structure-induced low efficiency, and potential safety concerns. Our finding presents the first demonstration of a self-activated nanoplatform for targeted and noninvasive deep-cancer therapy.

Boron and nitrogen co-doped single-layered graphene quantum dots: a high-affinity platform for visualizing the dynamic invasion of HIV DNA into living cells through fluorescence resonance energy transfer.

High-affinity binding of carbon nanomaterials with nucleobases, which is still a challenge, is the basis for DNA directed assembly and sensing. In this work, boron and nitrogen co-doped single-layered graphene quantum dots (BN-SGQDs) are designed as a high-affinity platform for nucleic acid detection and imaging in living cells, which has been confirmed by density functional theory (DFT) simulation and experiments. Owing to their excellent absorption and photoluminescence ability, the high quantum yield (QY 36.5%) yellow fluorescent BN-SGQDs could act as an energy donor in the fluorescence resonance energy transfer (FRET) process for nucleic acid detection. Furthermore, this BN-SGQD based sensing platform has been successfully adopted to visualize the dynamic invasion of human immunodeficiency virus (HIV) DNA into HeLa cells. The high-affinity platform has shown potential for biosensing in complicated biological samples.

Multicolor imaging of hydrogen peroxide level in living and apoptotic cells by a single fluorescent probe

To understand the entangled relationship between reactive oxygen species (ROS) and apoptosis, there is urgent need for simultaneous dynamic monitoring of these two important biological events. In this study, we have developed a fluorescent probe, pep4-NP1, which can simultaneously detect H2O2 and caspase 3, the respective markers of ROS and apoptosis. The probe contains a H2O2 fluorescence reporter (NP1) and Cy5 fluorescent chromophore connected by a caspase 3 specific recognition peptide. The detecting strategy was realized through a controllable fluorescence resonance energy transfer (FRET) process between NP1 and Cy5 of pep4-NP1, after reaction with H2O2, which was verified by molecular calculation and in vitro spectral studies. In the absent of caspase 3, the accumulation of H2O2 induces red fluorescence of pep4-NP1 centered at 663nm in living cells due to the existence of FRET. In contrast, FRET is inhibited in apoptotic cells due to cleavage of the peptide spacer of pep4-NP1 by over-expressed caspase 3. Consequently, green fluorescence (555nm) predominated when labelling production of H2O2 in apoptotic cells. Moreover, Pep4-NP1 shows excellent selectivity towards H2O2 and caspase 3 on their respective reaction sites. Therefore, pep4-NP1 can distinguish endogenously generated H2O2 between living cells and apoptotic cells with different fluorescence wavelengths, providing additional information on the ROS production pathways.

Amphiphilic carbon dots for sensitive detection, intracellular imaging of Al3+

In this paper, a simple and effective method was designed to synthesize hydrophobic carbon dots. Subsequently, amphiphilic fluorescent carbon dots (A-CDs) were synthesized by further surface modification. The result A-CDs show excellent optical properties with a quantum yield of 16.9%. It was interestingly found that morin (MR) and its fluorescent metal-ion complex (MR-Al3+) can successfully coordinate on the surface of A-CDs, the emission of A-CDs completely overlapped the absorption peak of MR-Al3+. Thus, the prepared A-CDs can be used as an effective fluorescent probe for Al3+ based on a fluorescence resonance energy transfer process. The sensing platform can realize real-time detection of Al3+ within 0.5 min. The fluorescence signals of the system were linearly correlated with the concentration of Al3+ over a range of 8–20 μM, with a detection limit of 0.113 μM. The method was also successfully applied to image the distribution of Al3+ in Human Umbilical Vein Endothelial Cells.

A theranostic prodrug based on FRET for real-time drug release monitoring in response to biothiols

The clinical applications of tradition prodrug are restricted to a certain extent due to its some defects such as side effects, low selectivity and single function. Herein, we designed a theranostic strategy based on the fluorescence resonance energy transfer (FRET) mechanism. The theranostic prodrug was constructed with an anticancer drug camptothecin (CPT), a cleavable linker based on disulfide bonds (SS) and a fluorophore naphthalimide derivative (NAP). For this drug delivery and reporting system (NAP-SS-CPT), FRET occurs between CPT (energy donor) and NAP (energy receptor); and upon cellular uptake by GSH-overexpressing cancer cells, disulfide bonds could be successfully cleaved by the high concentration of GSH, and FRET process was interrupted to achieve dual fluorescence response and specifically release of CPT. The drug delivery system features some favorable properties, like excellent pH-stability, high selectivity and cytotoxicity towards GSH-overexpressing cells and relatively lower cytotoxicity towards normal cells. Fluorescence analysis reveals that NAP-SS-CPT shows a ratiometric fluorescence signal under excitation at 400nm for quantitative detection of GSH. Intracellular fluorescence imaging studies indicate that the prodrug can be efficiently internalized in HeLa cells and used for real-time monitoring of drug release. Moreover, MTT and flow cytometry assay indicate that NAP-SS-CPT exhibits high pro-apoptotic effect for cancer cells. This strategy may provide a new approach for cancer diagnosis and therapy.

Covalent Surface Functionalization of Semiconducting Polymer Dots with β-Cyclodextrin for Fluorescent Ratiometric Assay of Cholesterol through Host-Guest Inclusion and FRET.

Special functionalization of semiconducting polymer dots (Pdots) is highly desired to expand their applications in chemo/biosening. Herein, carboxyl-functionalized poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1',3}-thiadiazole)] dots covalently tagged with aminated β-cyclodextrin (NH2-CD) have been designed to construct a ratiometric sensor for cholesterol (Cho). Using CD-Pdots as energy donors with rhodamine B (RB) as energy acceptors, a fluorescence resonance energy transfer (FRET) pair has been built because the host-guest interaction between RB and CD attached to Pdots brings donors and acceptors into close proximity. In the presence of Cho, the acceptors will depart from the donors because of the competitive inclusion interaction between Cho and RB with CD, resulting in the hindering of the FRET process between CD-Pdots and RB. On the basis of the turn-on fluorescence of CD-Pdots and turn-off fluorescence of RB, a sensitive ratiometric method for the determination of Cho in the concentration range from 25 to 350 nM with a detection limit of 4.9 nM was achieved. The proposed method was validated to determine free Cho in human serum samples with satisfactory results.

Combining Two-Photon-Activated Fluorescence Resonance Energy Transfer and Near-Infrared Photothermal Effect of Unimolecular Micelles for Enhanced Photodynamic Therapy.

Recent years have witnessed significant progress in the field of two-photon-activated photodynamic therapy (2P-PDT). However, the traditional photosensitizer (PS)-based 2P-PDT remains a critical challenge in clinics due to its low two-photon absorption (2PA) cross sections. Here, we propose that the therapeutic activity of current PSs can be enhanced through a combination of two-photon excited fluorescence resonance energy transfer (FRET) strategy and photothermal effect of near-infrared (NIR) light. A core-shell unimolecular micelle with a large two-photon-absorbing conjugated polymer core and thermoresponsive shell was constructed as a high two-photon light-harvesting material. After PSs were grafted onto the surface of a unimolecular micelle, the FRET process from the conjugated core to PSs could be readily switched "on" to kill cancer by the collapsed thermoresponsive shell due to the photothermal effect of NIR light. Such NIR-triggered FRET leads to an enhanced 2PA activity of the traditional PSs and, in turn, amplifies their cytotoxic singlet oxygen generation. Eventually, both in vitro and in vivo PDT efficiencies treated with the thermoresponsive micelles were dramatically enhanced under NIR light irradiation, as compared to pure PSs excited by traditional visible light. Such a facile and simple methodology for the enhancement of the photodynamic antitumor effect holds great promises for cancer therapy with further development.

Multi-dimensional, light-controlled switch of fluorescence resonance energy transfer based on orderly assembly of 0D dye@micro-micelles and 2D ultrathin-layered nanosheets

Fluorescence resonance energy transfer (FRET) systems have broad applications in visual detection, intelligent materials, and biological imaging, all of which favor the transmission of light through multiple dimensions and in diverse directions. Herein, we have demonstrated multi-dimensional (0D and 2D) FRET within a multi-layer ultrathin film (UTF) by employing a layer-by-layer (LBL) assembly technique. The anionic block copolymer micelle poly(tert-butyl acrylate-co-ethyl acrylate-co-methacrylic acid) (PTBEM) is chosen as a molecular carrier for the incorporation of bis(8-hydroxyquinolate) zinc (Znq2) and open-ring merocyanine (MC) (denoted as (Znq2/MC)@PTBEM). Alternatively, electrostatic assembly is performed with cationic layered double hydroxide (LDH) nanosheets (denoted as [(Znq2/MC)@PTBEM/LDH]n). This [(Znq2/MC)@PTBEM/LDH]n system offers a multi-dimensional propagation medium and ensures that the FRET donor and acceptor are located within their Forster radii in each direction. The system demonstrates a FRET process that can be switched via alternating ultraviolet/visible (UV/vis) irradiation, with tunable blue–green/red fluorescence, resulting in a FRET efficiency as high as 81.7%. It is expected that this assembly method, which uses 0D micelles on a 2D layered material, can be extended to other systems for further development of multi-dimensional FRET.

Fluorescent Peptide Beacons for the Selective Ratiometric Detection of Heparin.

Heparin is extensively used as an anticoagulant drug during surgery. Two fluorophore-functionalized cationic oligopeptides HS 1 and HS 2 were developed to monitor heparin ratiometrically in aqueous media. Upon binding to heparin, HS 1 and HS 2 undergo a conformational change from an open form to a folded form, which leads to a distinct change in the fluorescence properties. HS 1 switches from pyrene monomer emission to an excimer emission. For HS 2, a fluorescence resonance energy transfer (FRET) process is enabled between a naphthalene donor and a dansyl acceptor. This method is highly selective for heparin relative to other similar biological analytes such as hyaluronic acid or chondroitin sulfate. HS 1 and HS 2 could also detect heparin ratiometrically in diluted bovine serum. The strong ratiometric emission color change can also be observed by the naked eye. Addition of the polycationic protein protamine releases both HS 1 and HS 2 from their heparin complex, which simultaneously restores pyrene monomer emission for the first case and decreases the FRET process for the latter case, respectively. Dynamic light scattering (DLS) and AFM studies confirm aggregate formation of heparin with HS 1 and HS 2.

A new fluorescence probe based on fluorescein-diarylethene fluorescence resonance energy transfer system for rapid detection of Cd2+

A novel diarylethene derivative 1O with fluorescein-quinoline unit was designed and synthesized successfully. Under the stimulation of light and chemical, the diarylethene molecule exhibited multi-responsive photoswitchable properties. Moreover, the compound was a potential ‘naked eye’ chemosensor with significant color and fluorescence changes in the recognition of Cd2+ in tetrahydrofuran (THF). When the fluorescein spirolactam ring-opened form was triggered with Cd2+, an obvious red shift from 459 nm to 560 nm (101 nm) was observed in complex 1O′, and the emission intensity was enhanced by 8 fold with a concomitant fluorescence color change from dark to bright yellow. Significantly fluorescent quenching was observed in ring-closed isomer 1C′ due to the FRET (fluorescence resonance energy transfer) processes between fluorescein moiety and the ring-closed diarylethene moiety. The interference from other effective metal ions, particularly Zn2+, had not been observed. Finally, a molecular logic circuit was constructed with both light and chemical stimuli as inputs and fluorescence intensity at 560 nm as output.

Dual-Shell Fluorescent Nanoparticles for Self-Monitoring of pH-Responsive Molecule-Releasing in a Visualized Way.

The rational design and controlled synthesis of a smart device with flexibly tailored response ability is all along desirable for bioapplication but long remains a considerable challenge. Here, a pH-stimulated valve system with a visualized "on-off" mode is constructed through a dual-shell fluorescence resonance energy transfer (FRET) strategy. The dual shells refer to carbon dots and fluorescent molecules embedded polymethacrylic acid (F-PMAA) layers successively coating around a SiO2 core (ca. 120 nm), which play the roles as energy donor and acceptor, respectively. The total thickness of the dual-shell in the solid composite is ca. 10 nm. The priorities of this dual-shell FRET nanovalve stem from three facts: (1) the thin shell allows the formation of efficient FRET system without chemical bonding between energy donor and acceptor; (2) the maximum emission wavelength of CD layer is tunable in the range of 400-600 nm, thus providing a flexible energy donor for a wide variety of energy acceptors; (3) the outer F-PMAA shell with a pH-sensitive swelling-shrinking (on-off) behavior functions as a valve for regulating the FRET process. As such, a sensitive and stable pH ratiometric sensor with a working pH range of 3-6 has been built by simply encapsulating pH-responsive fluorescein isothiocyanate (FITC) into PMAA; a pH-dependent swelling-shrinking shuttle carrier with a finely controllable molecule-release behavior has been further fabricated using rhodamine B isothiocyanate (RBITC) as the energy donor and model guest molecule. Significantly, the controlled releasing process is visually self-monitorable.

Supramolecular FRET modulation by pseudorotaxane formation of a ditopic stilbazolium dye and carboxylato-pillar[5]arene

In this paper we introduce a new approach towards the modulation of fluorescence resonance energy transfer (FRET). Two stilbazolium dyes (A, D) exhibiting opposite fluorescence responses upon complexation with anionic, water soluble carboxylato-pillar[5]arene (WP5) were covalently linked via click chemistry, yielding a FRET-capable ditopic indicator (G). The pseudorotaxane formation of G with WP5 in pure water induced fluorescence enhancement combined with the modulation of the FRET process due to the interaction of the macrocycle with the two fluorophore units.

N, B-doped carbon dots as a sensitive fluorescence probe for Hg2 + ions and 2,4,6-trinitrophenol detection for bioimaging

Nitrogen and boron co-doped carbon dots (BCNDs1–3) were prepared from three kinds of borate via a facile hydrothermal method. The as-prepared BCNDs did not shift with the change of excitation wavelength and possess good water dispersibility, strong fluorescence emission with high fluorescent quantum yield of 29.01%, 51.42%, 68.28%, respectively. Subsequently, these BCNDs were exploited as excellent Hg2+ ion and 2,4,6-trinitrophenol (TNP) probe. The efficient selective detection of Hg2+ can be attributed to non-radiative electron/hole recombination annihilation through an effective electron transfer process and the detection of TNP can be attributed to the fluorescence resonance energy transfer process (FRET). The results show that the BCNDs2 is the most sensitive fluorescence probe for Hg2+ ions and TNP detection as low as Hg2+ 7.3nM and TNP 0.35μM compared with BCNDs1 and BCNDs3. The as-prepared BCNDs possess the advantages of good selectivity, fast response and a broad linear detection. They were applied to sensing and imaging of human umbilical vein endothelial cells, showing low cytotoxicity and good biocompatibility.