Time-resolved Fluorescence Decay Research Articles

Synthesis and Photophysical Properties of a Chiral Carbon Nanoring Containing Rubicene.

Herein we report the construction of an inherently chiral carbon nanoring, cyclo[7]paraphenylene-2,9-rubicene ([7]CPPRu2,9), by combining rubicene with a C-shaped synthon through the Suzuki-Miyaura coupling reaction. The structure was fully confirmed by high-resolution mass spectroscopies (HR-MS) and various NMR techniques. The photophysical properties were investigated by UV-vis absorption and fluorescence spectroscopy as well as the time-resolved fluorescence decay. Moreover, two enantiomers (M)/(P)-[7]CPPRu2,9 were successfully resolved by recyclable HPLC and studied by CD and CPL spectra.

Refolding SDS-mediated partially-unfolded proteins: A distinguishing role of tetraalkylammonium ionic liquids via mixed micellar aggregation

The current study reports a new strategy for ionic liquid (ILs) assisted refolding of sodium dodecyl sulfate (SDS)-induced partially unfolded protein via mixed micellar aggregate formation between SDS and the ionic liquid. This approach can indeed be utilized to keep many essential and sensitive proteins as active and prolong their shelf life. For SDS-induced partially unfolded proteins, the ionic liquid has been identified to function as a refolding agent. The phenomenon has been observed by us for the first time and we have thoroughly investigated the same utilizing a variety of spectroscopic, microscopic approaches, and attempted to rationalize from computational techniques as well. The steady-state fluorescence emission spectra and time-resolved fluorescence decay show that both the intrinsic emission intensity and the average lifetime, respectively, of the surfactant-induced partially-unfolded protein increase in the presence of ionic liquid, indicating a possible reversal of unfolding (refolding) of the protein (up to ∼95 % revival of luminescence intensity and average lifetime with respect to the native protein). The CD and FTIR results also confirmed that the α-helical content of the pre-unfolded protein reverts substantially and is very close to that of the native protein. To understand the refolding process of SDS-induced partially-unfolded protein, we have further studied the structural recovery of urea-induced pre-denatured protein utilizing the same ionic liquid. Interestingly, no such refolding was observed in this case. From the experimental results, it appears that ionic liquid is involved in scavenging the unfolding surfactant monomers by forming mixed-micellar aggregates where the ion-ion attachment is likely to have impact on the said process.

Design of CdS/Covalent Organic Framework as an efficient heterojunction photocatalyst for enhanced photocatalytic H2 evolution

In this study, we design a CdS/Covalent Organic Framework (COF) heterojunction to enhance the photocatalytic H2 evolution. The results demonstrate that the 30% CdS/TTCOF heterojunction exhibits the highest H2 production activity of 21.8 mmol g−1 under visible light, surpassing that of pure CdS and TTCOF by 8.1 and 18.2 times, respectively. Additionally, time-resolved fluorescence decay and steady-state photoluminescence spectra indicate that the enhanced photocatalytic performance of the CdS/TTCOF heterojunction can be ascribed to fast charge carrier transfer between CdS and TTCOF.

A highly stable TiO2/covalent organic framework heterojunction photocatalyst boosting charge transfer for visible-light-driven CO2 reduction

In this study, we present a novel heterojunction photocatalyst (TiO2-TTCOF) boosting charge transfer for visible-light-driven CO2 to CO conversion without photosensitizer or sacrificial agents. The 10% TiO2-TTCOF heterojunction photocatalyst is able to catalyze CO2 conversion, resulting in a highest CO production rate of 139.1 μmol g−1 with a selectivity of 96% and O2 production rate of 73.1 μmol g−1. Additionally, time-resolved fluorescence decay spectra confirmed the heterostructure between TTCOF and TiO2 can promote photoelectron transfer. The ATR-IFTS spectra indicated the photocatalytic reaction pathway.

Carbon nitride coupled with carbon nanohorns for improved photocatalytic hydrogen production and dyes degradation

In the present study we attempted to develop photoactive nanocomposites via the facile coupling of carbon nitride (CN) with single walled carbon nanohorns (CNHs). Photocatalytic activity was evaluated for the degradation of Rhodamine B (RhB) and the production of H2. The CNHs content noticeably affected the photoactivity of the nanocomposites and the best performing material exhibited a 3-fold increase in photocatalytic H2 production compared to pristine CN using 1 wt% Pt as co-catalyst. A systematic study was undertaken to explain the mechanistic aspects of the photo-reaction process. The active species responsible for the photodegradation of RhB were identified using reference reactions. Such species were further studied using in-situ spin-trap EPR experiments. Photoluminescence and time-resolved fluorescence decay kinetics suggested faster transfer of photogenerated electron/hole pairs resulting in reduced charge recombination phenomena in the nanocomposites. The combined photocatalytic application and characterization of the prepared materials revealed that the promotion of the redox reactions in based on improvements on the charge separation efficiency.

Highly efficient broadband near-infrared luminescence phosphors Ca3MgSn0.5Zr0.5Ge3O12:Pr3+,Cr3+ for multifunctional applications in pc-LEDs field

Exploring high-performance broadband near-infrared (NIR) emitting materials is crucial for the development of NIR devices. In this study, Ca3MgSn0.5Zr0.5Ge3O12:Cr3+ and rare earth ion Pr3+ co-doped Ca3MgSn0.5Zr0.5Ge3O12:Pr3+,Cr3+ phosphors were successfully synthesized. By utilizing time-resolved emission spectroscopy (TRES), photoluminescence (PL) spectra, and fluorescence decay curve, the Ca3MgSn0.5Zr0.5Ge3O12:Cr3+ phosphor is determined to exhibit a broadband emission (650–1150 nm) with a peak at 795 nm due to Cr3+ occupying multiple cationic sites. Ca3MgSn0.5Zr0.5Ge3O12:0.1Cr3+ has excellent thermal stability (86%@425 K), and co-doping Pr3+ ions into Ca3MgSn0.5Zr0.5Ge3O12:0.1Cr3+ obtains highly efficient NIR emission. The Ca3MgSn0.5Zr0.5Ge3O12:0.01Pr3+,0.1Cr3+ phosphor has quantum yield of 89.4% thanks to the energy transfer effect from Pr3+ to Cr3+. The fabricated NIR phosphor-converted light emitting diodes (pc-LEDs) by integrating the blue chip with Ca3MgSn0.5Zr0.5Ge3O12:0.01Pr3+,0.1Cr3+ has diverse applications including night vision, non-destructive testing, and medical imaging.

Embedding In2.77S4 into NCDs-(g-C3N5) hybrid materials to enhance photocatalytic hydrogen production and rhodamine B degradation by constructing electron-highways

We propose a potential solution to the problem of severe recombination of photogenerated electron-hole pairs in composite catalysts. The g-C3N5 has better electronic properties and photocatalytic efficiency than g-C3N4, and In2.77S4 is a typically sulfur-deficient sulfide with stable structure and strong visible light absorption. However, the In2.77S4/g-C3N5 composite catalyst has severe recombination of photogenerated electron-hole pairs, which limits its performance. To solve this problem, we introduced NCDs (nitrogen-doped carbon dots) into g-C3N5 to prepare hybrid material, which subsequently combined with In2.77S4. The high-efficiency S-scheme In2.77S4/NCDs-(g-C3N5) heterojunction was prepared by electrostatic self-assembly to prevent the thermal decomposition of g-C3N5. Photocatalytic experiments show that In2.77S4/NCDs-(g-C3N5) composite has excellent photodegradation efficiency of rhodamine B (94.23 %), high photocatalytic H2 production (7134 μmol·g−1h−1), and good reusability in the visible light. The H2 evolution rate of In2.77S4/NCDs-(g-C3N5) composite is about 30.10, 3.89 and 3.08 folds than In2.77S4, g-C3N5 and In2.77S4/g-C3N5, respectively. The photoluminescence spectroscopy (PL) and the time-resolved fluorescence decay (TRF) indicated a substantial reduction in photogenerated carrier recombination of In2.77S4/NCDs-(g-C3N5) compared to In2.77S4/g-C3N5. Taking advantage of the high conductivity of NCDs, the electron-highways were constructed in heterojunctions, which accelerates the interfacial depletion of useless electron-hole pairs and reserved more strong redox carriers. In addition, we inferred a possible energy band structure for In2.77S4/NCDs-(g-C3N5) heterojunction based on the energy band bending theory. This work provides an expandable idea for improving the utilization efficiency of photogenerated carriers by constructing electron-highways in heterojunctions.

Spectroscopic and in silico evaluation on the interactive behavior between substituted β-2,3-dihydrofuran naphthoquinones and human serum albumin

The interactive profile between human serum albumin (HSA, the main carrier of endogenous and exogenous compounds in the human bloodstream) and five potential anticandidal agents, namely 2,3-dihydro-2-phenyl-naphtho[1,2-b]furan-4,5‑dione (1) and its derivatives 2–5 was studied by biophysical techniques, i.e., UV–vis, circular dichroism, steady-state and time-resolved fluorescence, combined with in silico calculations. The Stern-Volmer quenching constant (KSV) trend in three different temperatures and the bimolecular quenching rate constant (kq ≈ 1012 M−1s−1) values indicated a ground-state association HSA:1–5 which was confirmed by time-resolved fluorescence decays. Both KSV and modified Stern-Volmer binding constant (Ka) values are in the order of 104 M−1, indicating a moderate binding affinity, following the same reported trend for 1,4-naphthoquinones (the isomeric form of the naphthoquinones under study). There is only one main binding site for HSA:1–5, probably the subdomain IIA where the Trp-214 residue can be found. The association is driven both enthalpically and entropically, perturbing both the microenvironment around Trp-214 residue and weakly the α-helix content of albumin. Overall, the β-2,3-dihydrofuran naphthoquinones 1–5 showed favorable binding affinity to HSA to achieve their therapeutical potential and control of effective dosages.

S-doped g-C3N4 for fluorescence sensing of Fe3 + and photocatalytic dye degradation under solar light

Sulfur doped graphitic carbon nitride nanosheets were synthesized via polycondensation reaction of urea-thiourea mixture. Structure and morphology were characterized by XRD (X-ray diffraction), SEM (scanning electron microscope), and XPS (X-ray Photoelectron Spectroscopy). DRS (diffuse reflectance spectroscopy), PL (Photoluminescence spectroscopy) and time-resolved fluorescence decay spectra were used to study the optical characteristics. The photocatalytic dye degradation of Rhodamine B (RhB) in the presence of as-synthesized catalysts was investigated with the help of a UV–visible spectrophotometer. The photocatalytic activity of carbon nitride prepared from urea-thiourea mixture is almost three times higher than that of the pure sample. The detection of Fe3+ was also investigated by using the fluorescence sensing method. The as-synthesized samples hold greater selectivity and sensitivity for fluorescence sensing of Fe3+within a range of 0–3 µM. This range is comparable to the performance of other Fe3+ fluorescent probes previously reported.

Synthetic dimethoxyxanthones bind similarly to human serum albumin compared with highly oxygenated xanthones

Spectroscopic studies were carried out for the interaction of the bioactive compounds 2,3-dimethoxyxanthone (1) and 3,4-dimethoxyxanthone (2) with human serum albumin (HSA). The UV absorption, steady-state, and time-resolved fluorescence spectroscopy studies showed that 1 and 2 interact with HSA through a ground-state association. The decrease in the Stern-Volmer constant (KSV) values with increasing temperature, and the bimolecular quenching rate constant (kq) values in the order of 1012 M−1s−1 indicated a static fluorescence quenching mechanism, corroborating with time-resolved fluorescence decays. The association constant (Ka) values in the order of 104 M−1 indicated a moderate interaction between these xanthones and HSA. Circular dichroism experiments showed weak perturbation on the secondary structure of albumin after the interaction with 1 and 2. Thermodynamic parameters suggested that the binding is entropically (for HSA:1, ΔS° 0.012 ± 0.003 and for HSA:2 0.008 ± 0.002 J/molK) and enthalpically (for HSA:1, ΔH° -24.0 ± 0.99 and for HSA:2 -25.6 ± 0.67 kJ/mol) controlled, with a Gibbs free energy change (ΔG°) close to -28.0 kJ/mol in both cases. Competitive drug-displacement and molecular docking results showed that 1 and 2 could interact not only with subdomain IIA, where Trp-214 residue can be found, but also with subdomains IIIA and IB. Hydrogen bonding, electrostatic, and hydrophobic interactions were detected as the main binding forces to stabilize the association HSA:1 and HSA:2. Overall, the dimethoxyxanthones have similar binding affinity compared with highly oxygenated xanthones, e.g., mangiferin, gentiacaulein, and norswertianin.

Investigation of CO2 photoreduction mechanism over the Zn2V2O7/Zn3V2O8/ZnO Z-scheme system

CO2 photoreduction under mild conditions remains challenging, attributing to sluggish kinetics of complex coupling process of multi-electrons-protons and inefficient electron-hole pairs utilization. Herein, with Zn3V2O8 as a phase transformation material, we construct an effective Zn2V2O7/Zn3V2O8/ZnO (OVZn) Z-scheme system by partial decomposition of Zn3V2O8 into Zn2V2O7 and ZnO. Time-resolved fluorescence decay (TRFD) spectra investigation shows that the photogenerated electrons of Zn2V2O7 and ZnO recombine with the holes of Zn3V2O8, retaining more reductive electron of Zn3V2O8 for CO2 reduction. Moreover, in-situ Fourier-transform infrared spectroscopy suggests that the heterostructure can lower the energy barrier of CO desorption by changing bridge-bonded CO to linear-bonded CO and optimizing the energy barrier of CO production. Moreover, Cu, Ag and Au loading on OVZn greatly enhance light harvesting and promote photoelectric conversion, producing much photogenerated electron-hole pairs for CO2 reduction. OVZn and metal loaded OVZn have better photocatalytic performance, showing application superiority on CO2 photoreduction.

Initiator-Activation Strategy-Enabled Organocatalyzed Reversible-Deactivation Radical Polymerization Driven by Light.

Organocatalyzed reversible-deactivation radical polymerizations (RDRPs) are attractive for many applications. Here, we developed photoredox-mediated RDRP by activating (hetero)aryl sulfonyl chloride (ArSO2 Cl) initiators with pyridines and designing a novel bis(phenothiazine)arene catalyst. The in situ formed sulfonyl pyridinium intermediates effectively promote controlled chain-growth from ArSO2 Cl, enabling access to various well-defined polymers with high initiation efficiencies and controlled dispersities under mild conditions. This versatile method allows "ON/OFF" temporal control, chain-extension, facile synthesis of different polymer brushes via organocatalyzed grafting reactions from linear chains. Time-resolved fluorescence decay studies and calculations support the reaction mechanism. This work provides a transition-metal-free RDRP to tailor polymers with readily available aromatic initiators, and will promote the design of polymerization leveraged from photoredox catalysis.

Preparation of Laterally Chloro-Substituted Schiff Base Ester Liquid Crystals: Mesomorphic and Optical Properties

A new class of Schiff base/ester compounds: ICln, 4-((2′-chlorophenylimino)methyl)phenyl-4″-alkoxy benzoates, were synthesized and their mesophase characteristics and thermal behavior were evaluated. Differential scanning calorimetry (DSC) was used to study mesophase transitions, and polarized optical microscopy was carried out to identify the phases (POM). The results show that all compounds are monomorphic, and enantiotropic nematic (N) phases were seen at all side chains. It was found that lateral Cl atoms in the terminal benzene ring influence both conformation and mesomorphic properties. Comparisons between the present investigated lateral Cl derivatives and their laterally neat, as well as their isomeric, compounds have been briefly discussed. Results revealed that the insertion of lateral Cl substituent in the molecular structure impacts the type and stability of the formed mesophases. The exchanges of the ester-connecting moiety improve their thermal nematic stability than their previously prepared structurally isomeric derivatives. These compounds exhibit a broad absorption in the UV-Visible region, including a peak in UV region and a tail around 550 nm, and there were observed to be absorption tail increases and energy band gap decreases with the increase of the alkoxy side chain length. The photoluminescence (PL) intensity was noted to be quenched for the bulky alkoxy group ascribed to non-radiative recombination through the defect states. Moreover, time resolved fluorescence decay spectra reveal that both the radiative and non-radiative recombination lifetime increases with the increase of alkoxy side chain length.

Construction of a Chiral Fluorescent Probe for Tryptophan Enantiomers/Ascorbic Acid Identification.

Chiral recognition of amino acid enantiomers is critical in enhancing drug efficacy, detecting disease markers, and understanding physiological processes. Enantioselective fluorescent identification has gained attention among researchers due to its nontoxicity, easy synthesis, and biocompatibility. In this work, chiral fluorescent carbon dots (CCDs) were produced through a hydrothermal reaction followed by chiral modification. The fluorescent probe, Fe3+-CCDs (F-CCDs), was constructed by complexing Fe3+ with CCDs to differentiate between the enantiomers of tryptophan (Trp) and determine ascorbic acid (AA) through an "on-off-on" response. It is worth noting that l-Trp can greatly enhance the fluorescence of F-CCDs with a blue shift, whereas d-Trp does not have any effect on the fluorescence of F-CCDs. F-CCDs showed a low limit of detection (LOD) for l-Trp and l-AA, with an LOD of 3.98 and 6.28 μM, respectively. The chiral recognition mechanism of tryptophan enantiomers using F-CCDs was proposed based on the interaction force between the enantiomers and F-CCDs, as confirmed by UV-vis absorption spectroscopy and density functional theory calculations. The determination of l-AA by F-CCDs was also confirmed through the binding of l-AA to Fe3+ to release CCDs, as seen in UV-vis absorption spectra and time-resolved fluorescence decays. In addition, AND and OR gates were constructed based on the different responses of CCDs to Fe3+ and Fe3+-CCDs to l-Trp/d-Trp, demonstrating the significance of molecular-level logic gates in drug detection and clinical diagnosis.

Switching of the Polarity-Sensitive Aggregation Pattern of a Thiosemicarbazone-Based Anticancer Luminophore and Its Involvement in Cellular Apoptosis of the Human Lung Cancer Cell Line.

Elucidation of the photophysical and biochemical properties of small molecules can facilitate their applications as prospective therapeutic imaging (theragnostic) agents. Herein, we demonstrate the luminescence behavior of a strategically designed potential therapeutic thiosemicarbazone derivative, (E)-1-(4-(diethylamino)-2-hydroxybenzylidene)-4,4-dimethylthiosemicarbazide (DAHTS), accompanied by the illustration of its solvation and solvation dynamics using spectroscopic techniques and exploring its promising antitumor activities by adopting the necessary biochemical assays. Solvent-dependent photophysical properties, namely UV-vis absorption, fluorescence emission, and excitation profiles, concentration-dependent studies, and time-resolved fluorescence decays, serve as footprints to explain the existence of DAHTS monomers, its excited-state intramolecular proton transfer (ESIPT) product, and dimeric and aggregated forms. The emission intensity progressively intensifies with increasing polarity and proticity of the solvents up to MeOH, but in water, a sudden dip is seen. Solvent polarity and H-bonding modulate the fluorescence behavior of the primary emission peak and significantly influence the formation of the dimer and DAHTS aggregates. The designed luminophore (DAHTS) exhibits significant antiproliferative activity against the human lung cancer (A549) cell lines with inhibitory concentrations (IC50) of 16.88 and 11.92 μM for 24 and 48 h, respectively. DAHTS effectively reduces the cell viability and induces cytotoxicity with extensive morphological changes in A549 cells in the form of spikes when compared to the normal HEK cell lines. More importantly, it increases the p53 expression at the mRNA level that consolidates its potential therapeutic activity. The effect of DAHTS on apoptotic pathways against the A549 cell line has been investigated to determine its probable mechanism of cell death. Thus, the all-inclusive understanding of the photophysical properties and the necessary biochemical assays put forward important steps toward tailoring the thiosemicarbazone core structure for favorable cancer theragnostic applications in academic and pharmaceutical research.

Comparative studies on the aggregate formation of synthesized zwitterionic gemini and monomeric surfactants in the presence of the amphiphilic antipsychotic drug chlorpromazine hydrochloride in aqueous solution: an experimental and theoretical approach.

The formation of aggregates, which are widely used in the field of biochemistry and the medical industry, was studied with different compositions of alkyl betaine gemini surfactant (C14Ab) in conjugation with chlorpromazine hydrochloride (CPZ). The results were compared with those of a single-chain zwitterionic surfactant (C12DmCB) of the same type with CPZ. Dynamic light scattering (DLS), confocal laser scanning microscopy (CLSM), and transmission electron microscopy (TEM) methods were used to distinguish the aggregates for the CPZ/C14Ab system in aqueous solutions above a certain mole fraction of the drug CPZ (αCPZ = 0.2). Time-resolved fluorescence decay measurements of acridine orange revealed relative polarity near the head group regions of mixed micelle (CPZ/C14Ab and CPZ/C12DmCB) systems. The hydrophilic environment around the head group regions of the CPZ/C14Ab system was different from that in the case of the CPZ/C12DmCB system. On the other hand, several theoretical models were employed (Clint, Rubingh, Motomura, and SPB) for mixed micellar systems to elucidate the different interaction parameters. Such a systematic study of a zwitterionic gemini amphiphile and its interaction with other amphiphiles and an amphiphilic drug molecule is rare in the literature.

Rotational dynamics of 7-(dimethyl amino)-4-methoxy-1- methyl-1, 8-napthyridin-2(1H)-one in DMSO and acetonitrile solvents

Steady-State anisotropy and time-resolved fluorescence decay measurements have been carried out by varying temperatures in DMSO and acetonitrile solvents to study the rotational reorientation dynamics of 7-(dimethylamino)-4-methoxy-1-methyl-1,8-napthyridin-2(1H)-one(Quinolon-390). Experimentally determined rotational re-orientation time values in DMSO are found to be higher than acetonitrile, which implies that Qu-390 experiences more friction in DMSO than acetonitrile. To understand this friction, the theoretically measured rotational reorientation times using Stokes-Einstein’s-Debye (SED), Geirer-Wirtz (GW), and Dote-Kivelson and Schwartz (DKS) models are compared with experimental ones. Theoretically, estimated Qu-390 rotational reorientation times in DMSO and acetonitrile underestimate the experimental values which emphasize that mechanical friction contribution is less and dielectric friction contribution is more. Interestingly the experimental value and stick theoretical value 164 Ps at around 320 K is the same in DMSO.

Spectral analysis on the acceptor concentration-dependent fluorescence resonance energy transfer process in CuInS2@ZnS-SQ complexes.

Owing to the broad spectral response and flexible choices of donors and acceptors, fluorescence resonance energy transfer (FRET) system based on quantum dots (QDs) is a potential candidate for enhancing performance of solar cells and other optoelectronic devices. Thus it is necessary to develop such FRET systems with high efficiency and understand the involved photophysical dynamics. Here, with type I CuInS2@ZnS core-shell quantum dots as the energy donor, series of CuInS2@ZnS-SQ complexes are synthesized by adjusting the acceptor (squaric acid, SQ) concentration. The FRET dynamics of the samples is systematically investigated by virtue of steady-state emission, time-resolved fluorescence decay, and transient absorption measurements. The experimental results display a positive correlation between the energy transfer efficient (η). The best energy transfer efficient achieved from experimental data is 52%. This work provides better understanding of the photophysical dynamics in similar complexes and facilitates further development of new photoelectronic devices based on relevant FRET systems.

Construction of naphthalimide-based fluorescent amphiphilic aggregates and sensitive detection of persulfate and pyrophosphate anions

Detection of important anions is significant and challenging. Persulfate (S2O82-) and pyrophosphate (P2O74-) are two specific anions attracting extensive attentions as they have important effects on biological processes and environmental systems. A fluorescent amphiphilic molecule based on naphthalimide derivative was synthesized and it can form aggregates in aqueous solution. The fluorescent aggregates have shown selective fluorescence quenching responses to both S2O82- and P2O74- over a series of other anions. Moreover, the sensitivity is very high, and the detection limits of S2O82- and P2O74- are determined to be 5.2 nM and 19 nM, respectively. Time-resolved fluorescence decay measurements realized that the quenching is static in nature that could be due to the electrostatic interaction between the anions and cationic probes. Dynamic light scattering measurements revealed that the two anions have different effects on the aggregate size change, which could be further used to discriminate between the two anions with the aid of Tyndall effect test. Moreover, the probe aggregates can also detect the two anions in tap water and are used to prepare paper sensor for fast visual detection of the two anion analytes.

In-situ covalent bonding of carbon dots on two-dimensional tungsten disulfide interfaces for effective monitoring and remediation of chlortetracycline residue

• 2D WS 2 /CDs multifunctional nanomaterial was prepared by in-situ covalent bonding. • 2D WS 2 /CDs nanocomposite could be simultaneous detection and degradation of CTC. • The possible mechanisms for the detection and degradation of CTC were investigated. • This work is expected to provide a new idea for design of multifunctional platform. In view of the increasing threat of chlortetracycline (CTC) in water to human health and the ecological environment, how to detect and remove CTC in wastewater simply and effectively remains an important and challenging task. Herein, a multifunctional platform for the simultaneous detection and degradation of CTC is developed by in-situ synthesis of carbon dots (CDs) in the two-dimensional (2D) WS 2 interface by covalent bonding. The as-prepared 2D WS 2 /CDs nanocomposites can not only be used as an intelligent fluorescence probe for CTC detection with good sensitivity (LOD = 7.5 nM) and selectivity but also has good photodegradation ability for CTC (degradation efficiency attained 85.58%). Moreover, the possible mechanisms for the detection and photodegradation of CTC by 2D WS 2 /CDs were also investigated by theoretical calculations, time-resolved fluorescence decay curves, and electron spin resonance (ESR) analyses. The exceptional photoelectric properties of 2D WS 2 /CDs are ascribed to the CDs bound onto the 2D WS 2 interface by covalent bonding forming heterojunctions, which effectively promote strong interfacial interactions between CDs and 2D WS 2 , thereby providing more effective charge transfer and enhancing the detection efficiency and photocatalytic activity. In addition, the possible degradation pathway for CTC was speculated via identification of intermediates and frontier electron density calculation. Overall, this study not only proves that the 2D WS 2 /CDs nanocomposites have great potential for the simultaneous detection and degradation of CTC in aquatic environments but also provides a novel idea for the efficient and stable design of multifunctional nanomaterials for environmental pollution monitoring and purification, which is of great significance to both practical applications and basic research.