Molecular Orbital States Research Articles

Molecular design of furanoacene-based singlet fission sensitizers combining diradical character and cross-substitution

Singlet fission (SF) suffers from the scarcity of available SF chromophores and sensitizers. Tetracene, pentacene and their derivatives, are two typical model systems for the study of SF photophysical phenomena. Herein, the analogues of polyacenes, furanoacenes and their derivatives, were evaluated as potential SF chromophores and sensitizers through a theoretical study. The primary photostability were evaluated by the frontier molecular orbital energy levels, diradical characters and SF relevant excited state energies according to the type-I and −II photodegradation mechanisms. The cross-substitutions by combining central substitutions with triple bonds and terminal substituents enhance photostability, tune the SF relevant excited states efficiently, and give more appropriate E(T1) to be SF sensitizers. This work helps to give better understanding of the electronic structures and SF capability of furanoacenes.

Spin polarization and transport of hybrid interface states in π-stacked magnetic molecular junctions

Based on the first-principles method, the spin polarization and transport properties of the hybrid interface states (HIS) in π-stacked three-layer triphenylene molecular junction are studied theoretically. By rotating the torsion angle between two neighbor layers, the π-π interaction strength is adjusted. The results demonstrate that the HIS, generated by strong pz-d hybridization between molecules and ferromagnetic electrodes, can easily transfer to the central layer via a strong π-π interaction with similar spin polarization. A weak π-π interaction will block the transfer of the HIS, where the discrete molecular orbital states dominate the central molecule. However, an enhancement of the spin polarization for the molecular frontier orbital states is observed. The transport calculation shows that efficient transport of the HIS is realized in the π-stacked system, where the largest current appears at a strong π-π interaction but a significant current spin polarization appears at a weak π-π interaction. This work deepens our understanding of the role of the HIS in π-stacked organic systems.

Fluorinated silane self-assembled monolayer modification of V2O5 for enhanced hole injection and device efficiency

This study introduces a new approach to enhance hole injection in organic light-emitting diodes (OLEDs) by modifying the energy band alignment. This enhancement is achieved by incorporating gap states near the Fermi level through the application of a 1H,1H,2H,2H-perfluorooctyltriethoxysilane self-assembled monolayer (F8SAM) coating on V2O5. Compared to thermally evaporated V2O5, the F8SAM coating induces greater oxygen deficiency, reducing the V2O5 (V5+) content from 84.2 % to 76.9 % and increasing the VO2 (V4+) content from 15.7 % to 23.0 %. This modification causes both the highest occupied molecular orbital and gap state levels to move closer to the Fermi level, facilitated by increased oxygen vacancies, high carrier concentration, and delocalized free electrons. The alteration in the gap state provides a more accessible pathway for efficient hole injection, as confirmed in optoelectronic green light devices, which demonstrate a wavelength of 530 ± 5 nm. Significantly, devices incorporating a double-layer hole-injection layer exhibit a 5-fold increase in maximum luminance, a 1.6-fold increase in current efficiency, and a 1.7-fold increase in power efficiency compared to devices with an unmodified V2O5 film. The enhanced performance is attributed to the well-aligned F8SAM on V2O5, which increases the density of hole states and thereby improves device performance. This study demonstrates a practical method for modulating the cation valence state of V2O5, offering a pathway toward improved hole injection and, consequently, more efficient and functional OLED devices.

Rapid Prediction of Energy Level Alignment and Conductance of Single‐Molecule Junctions Through Intramolecular Dipole Moment

AbstractHow substituents affect the conductance of single‐molecule junctions has been a subject of ongoing debate. Here, a comparative study on the transport properties across a broader range of experimentally proposed and representative π‐conjugated molecular systems, each characterized by prototypical backbone motifs with distinct terminal groups and featuring a range of substituents is conducted. Employing the non‐equilibrium Green's function method within density functional theory, this investigation reveals a significant impact on junction conductance due to asymmetric characteristics arising from both electronic and spatial effects induced by the di‐substituents of phenanthrene analogs with C═C or B─N motifs. Remarkably, a linear correlation is uncovered, either negative or positive, between the dipole moment of the molecules and the junction conductance, contingent upon whether the transport is governed by the highest occupied molecular orbital (HOMO) or lowest unoccupied molecular orbital (LUMO) states. Furthermore, the validity of this proposed dipole moment descriptor is substantiated across various substituted series, including 2,7‐dipyridylfluorene, oligo(phenylene ethynylene), and 1,4‐diaminobenzene. These findings underscore the pivotal role of individual molecular dipole moment, easily determinable, in offering precise predictive insight into the conductance of intricate molecular junctions.

Partial molecular orbitals in face-sharing 3d manganese trimer: Comparative studies on Ba4TaMn3O12 and Ba4NbMn3O12

We present a molecular orbital candidate Ba4TaMn3O12 with a face-sharing octahedra trimer, by comparing it with a related compound Ba4NbMn3O12. The synthesis of the polycrystalline powder is optimized by suppressing the secondary impurity phase via x-ray diffraction. Magnetic susceptibility measurements on the optimized samples reveal a weak magnetic hysteresis with magnetic transitions consistent with heat capacity results. The effective magnetic moments from susceptibility indicate a strongly coupled S=2 antiferromagnetic trimer at around room temperature, whereas the estimated magnetic entropy from heat capacity suggests the localized S=3/2 timer. These results can be explainable by a partial molecular orbital state, in which three t2g electrons are localized in each Mn ion and one eg electron is delocalized over two-end Mn ions of the trimer based on density functional theory calculations. This unconventional 3d orbital state is comprehended as a consequence of competition between the hybrid interatomic orbitals within the Mn trimer and the local moment formation by on-site Coulomb correlations. Published by the American Physical Society 2024

X-ray Photoelectron Spectroscopy and Optical Studies of Assembled Gold Clusters

The electronic structures and optical properties of assembled gold nanoclusters prepared through wet chemical method have been investigated. The scanning electron microscopic analysis revealed gold clusters growing into beaded nanowires. The core level electronic states of the samples analyzed using X-ray Photoelectron spectroscopy, confirm the presence of gold. Further, the shift of core 4f orbitals towards higher energy indicates the interaction between Au and ligand in comparison with the bulk counterpart. The appearance of a sharp peak at 371 nm in the optical absorption spectrum refers to the excitonic transition between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) states. The luminescence peak observed at 403 nm and 615 nm may be due to the transitions between HOMO-LUMO gaps and the surface states and/or states originating from cluster-ligand interactions, respectively.

Superatom Molecular Orbitals of Endohedral C82.

Understanding superatom molecular orbital (SAMO) states in fullerene derivatives has been in the limelight ever since the first discovery of SAMOs owing to the fundamental interest in this topic as well as to the possible applications in molecular switches and other organic electronics. Nevertheless, very few reports have been published on SAMO states of larger fullerenes so far. Using density functional theory, we attempt to partially remedy this situation by presenting a study on SAMO states in C82 and its Ca and Sc endohedrally doped derivatives, comparing results with previous relevant findings for C60. We find that C82 possesses higher SAMO energies compared to C60, as associated with the symmetry of the molecule, and that endohedral doping leads to energetically favorable side positions of Ca and Sc inside the C82 cage. Among the two, Sc@C82 has more stable SAMO states compared to Ca@C82 as reflected by the shift in the density of states, while the charge states are found to be similar. In the case of the monolayer form, the pz- and 2s-SAMO orbitals overlap with the nearest neighbors, causing parabolic band dispersion with the formation of near free electron states and that the SAMO state energies move closer to the Fermi energy compared to the related molecules. These findings provide promising information about the distribution of SAMO states in C82 fullerene, which can be further relevant in studies of SAMO states of higher fullerenes and for coming applications of these systems.

Electronic and Structural Properties of Core-Shell Amino-Silica Nanoparticles: DFT And SCC-DFTB Calculation

Introduction: Silica nanoparticles (SNP) are extremely promising tools in nanotechnology and nano medicine. In most of applications such as capture and release of bacteriophage viruses the nano-structures of silica are coated by bio-compatible groups such as amine compounds. The presence of amino groups on the surface of the biosensors enables the installation of analyte receptors and antifouling agents such as oligo (ethylene oxide). Therefore, in this study, the electronic and structural properties of Core-Shell amino- Silica Nanoparticles are investigated.Material and Methods: In this investigation, we aim at obtaining the optimized structures and evaluate the geometries of the ground state for (SiO2) n (n=16, 20) nanoclusters. The electronic properties computed by density functional theory with GGA approximation and SCC-DFTB with hybrid Slater-Koster files are investigated and the effect of functionalization on such properties is discussed.Results: Solvolysis of studied structures is examined and it is shown that the highest occupied and lowest unoccupied molecular orbital states shift to obviously higher energy levels, which lead to more stable hydrogenated nanoclusters. The stability of nanoclusters rises by functionalization with amino and methylamine groups. Charge analysis of functionalized systems indicates the reactivity of nanoclusters. The results obtained in this paper are useful for chemical and biochemical applications of silica nanostructures.Conclusion: Results show that the length of amine hydrocarbon chain can control the electronic and magnetic properties of studied silica nanocluster (SNP) with different number of SiO2 unit. Pure ultra-small nanocluster shows the impressive spin splitting around the Fermi level, which is due to the spin splitting of outer silicon atoms. This feature of silica nanoclusters may be notable for applications in electronics.

Matrix of orthogonalized atomic orbital coefficients representation for radicals and ions.

Chemical (molecular, quantum) machine learning relies on representing molecules in unique and informative ways. Here, we present the matrix of orthogonalized atomic orbital coefficients (MAOC) as a quantum-inspired molecular and atomic representation containing both structural (composition and geometry) and electronic (charge and spin multiplicity) information. MAOC is based on a cost-effective localization scheme that represents localized orbitals via a predefined set of atomic orbitals. The latter can be constructed from such small atom-centered basis sets as pcseg-0 and STO-3G in conjunction with guess (non-optimized) electronic configuration of the molecule. Importantly, MAOC is suitable for representing monatomic, molecular, and periodic systems and can distinguish compounds with identical compositions and geometries but distinct charges and spin multiplicities. Using principal component analysis, we constructed a more compact but equally powerful version of MAOC-PCX-MAOC. To test the performance of full and reduced MAOC and several other representations (CM, SOAP, SLATM, and SPAHM), we used a kernel ridge regression machine learning model to predict frontier molecular orbital energy levels and ground state single-point energies for chemically diverse neutral and charged, closed- and open-shell molecules from an extended QM7b dataset, as well as two new datasets, N-HPC-1 (N-heteropolycycles) and REDOX (nitroxyl and phenoxyl radicals, carbonyl, and cyano compounds). MAOC affords accuracy that is either similar or superior to other representations for a range of chemical properties and systems.

Synergistic effect of Zn2GeO4 nanorod decorated metal organic framework ZIF-67 and its metal ligand charge transfer effect towards the photocatalytic CO2 reduction and C–C coupling

Metal-organic framework (MOF) especially zeolitic imidazole framework (ZIF-67) has shown tremendous efficiency in the field of CO2 adsorption, storage, and conversion due to its huge surface area and metal ligand charge transfer effect. A metal organic imidazole framework-based heterojunction, Zn2GeO4/ZIF-67 nanocomposite has been successfully synthesized where Zn2GeO4 nanorod deposited on the surface of high crystalline ZIF-67 to form an electronic Z scheme mechanism. The Zn2GeO4/ZIF-67 nanocomposite containing 20% Zn2GeO4 nanorod exhibit at about 1.62 times higher methanol production (41.16 μmol/g) than pure ZIF-67 (25.39 μmol/g) and the highest ethanol production was 1.53 times higher (32.66 μmol/g) than pure ZIF-67 (21.34 μmol/g) after 8 h of light irradiation. The electronic interaction of ZIF-67 and Zn2GeO4 has been studied theoretically using density functional theory calculation. Molecular orbital transition and excitation states were also calculated using time-dependent density functional theory calculation. The reaction pathway for CO2 reduction was determined by calculating free energy for each charge transfer intermediates.

Machine-Learned Electronically Excited States with the MolOrbImage Generated from the Molecular Ground State.

We present a general machine learning framework for probing the electronic state properties using the novel quantum descriptor MolOrbImage. Each pixel of the MolOrbImage records the quantum information generated by the integration of the physical operator with a pair of bra and ket molecular orbital (MO) states. Inspired by the success of deep convolutional neural networks (NNs) in computer vision, we have implemented the convolutional-layer-dominated MO-NN model. Using the orbital energy and electron repulsion integral MolOrbImages, the MO-NN model achieves promising prediction accuracies against the ADC(2)/cc-pVTZ reference for transition energies to both low-lying singlet [mean absolute error (MAE) < 0.16 eV] and triplet (MAE < 0.14 eV) states. An apparent improvement in the prediction of oscillator strength, which has been shown to be challenging previously, has been demonstrated in this study. Moreover, the transferability test indicates the remarkable extrapolation capacity of the MO-NN model to describe the out of data set systems.

Synthesis and Unexpected Optical Properties of Ionic Phosphorus Heterocycles with P-Regulated Noncovalent Interactions.

Optoelectronic properties of organic chromophores (OCPs) are to a large extent dictated by the chemical structures. Herein, we synthesized a new series of ionic phosphorus(P)-heteropines via the methylation of the P(III) center. Our studies revealed that methylation is highly dependent on the P(III) environments (NPN, NPC, and CPC), in which adjacent nitrogen atoms greatly withdraw electron density of the P(III) center. The observation of noncovalent interactions between solvent molecules and the molecular backbones of the related P-heterocycle in the single crystal structure implied tunable molecular conformations. Different from the red-shifted absorption and emission spectra of ionic P-OCPs induced by either decreased lowest unoccupied molecular orbital (LUMO) or intramolecular charge transfer (ICT) state in previous studies, current ionic P-heterocycles exhibit blue-shifted absorption and emission spectra compared to the nonionic counterparts. Our experimental and theoretical studies suggest that the unexpected photophysical characters are probably due to the counter-anion induced structure twisting via intermolecular noncovalent interactions between NH-indole and O(OTf), and/or strong intermolecular O···F bonding between O(MI) and F(OTf). Our studies also revealed that the P-environments (NPN, NPC, and CPC) conjunctly impact the photophysical properties of the ionic P-heteropines. Overall, the fact that the P-environment-regulated noncovalent interactions induce the rich structure dynamics and photophysics offers us with a new and effective strategy to fine-tune the optical properties of OCPs.

Universal Band Alignment Rule for Perovskite/Organic Heterojunction Interfaces

In contrast with the band alignment rule governing conventional semiconductor heterojunctions, the Fermi level position (i.e., work function, ϕpsk) of the perovskite and the differences in ionization energies of the organics are shown to dictate the band alignment and band offsets at perovskite/organic heterojunction interfaces. The experimental data show that the interface band alignments follow a universal alignment rule with three different energy windows: pinning of unoccupied molecular orbital states (LUMO) to the perovskite Fermi level, band offsets mediated by perovskite work functions, and pinning of occupied molecular orbital states (HOMO) to the perovskite Fermi level. The surface-passivated perovskites and several common native perovskites are all found to follow the same band alignment rule. Data scattering in measured band offsets, however, is observed on the same type of perovskites without proper surface passivation treatment. Solar cells made on the perovskites without surface passivation are also found to exhibit a large dispersive distribution in energy conversion efficiencies.

Three-Electron Two-Centered Bond and Single-Electron Transfer Mechanism of Water Splitting via a Copper–Bipyridine Complex

We report the atomistic and electronic details of the mechanistic pathway of the oxygen-oxygen bond formation catalyzed by a copper-2,2'-bipyridine complex. Density functional theory-based molecular dynamics simulations and enhanced sampling methods were employed for this study. The thermodynamics and electronic structure of the oxygen-oxygen bond formation are presented in this study by considering the cis-bishydroxo, [CuIII(bpy)(OH)2]+, and cis-(hydroxo)oxo, [CuIV(bpy)(OH)(═O)]+, complexes as active catalysts. In the cis-bishydroxo complex, the hydroxide transfer requires a higher kinetic barrier than the proton transfer process. In the case of [CuIV(bpy)(OH)(═O)]+, the proton transfer requires a higher free energy than the hydroxide one. The peroxide bond formation is thermodynamically favorable for the [CuIV(bpy)(OH)(═O)]+ complex compared with the other. The hydroxide ion is transferred to one of the Cu-OH moieties, and the proton is transferred to the solvent. The free energy barrier for this migration is higher than that for the former transfer. From the analysis of molecular orbitals, it is found that the electron density is primarily present on the water molecules near the active sites in the highest occupied molecular orbital (HOMO) state and lowest unoccupied molecular orbital (LUMO) of the ligands. Natural bond orbital (NBO) analysis reveals the electron transfer process during the oxygen-oxygen bond formation. The σ*Cu(dxz)-O(p) orbitals are involved in the oxygen-oxygen bond formation. During the bond formation, three-electron two-centered (3e--2C) bonds are observed in [CuIII(bpy)(OH)2]+ during the transfer of the hydroxide before the formation of the oxygen-oxygen bond.

High reactive oxygen species produced from fluorescence carbon dots for anticancer and photodynamic therapies: A review.

High-photoluminescence carbon dots (CDs) were synthesized from various sources and various methods using two approaches, namely bottom up and top down, with emission-dependent excitation wavelength. Electronic transition from the higher-occupied molecular orbital (HOMO) state to the lowest-unoccupied molecular orbital(LUMO) state, surface defect states, wider excitation spectrum, higher quantum yield, efficient energy transfer, and element doping affected the fluorescence properties of CDs. Using 102 references listed in this review, the authors studied the relationship between fluorescence mechanism and reactive oxygen species (ROS) produced for photodynamic therapy (PDT) and materials anticancer applications. We described how the radical atom or ROS work as anticancer therapy and PDT and described the chemical reaction of high-resolution fluorescence CDs. We summarized experimental techniques that are used for producing CDs and discussed their characteristics. Finally, conclusions and future prospects in this field are also discussed. The important characteristics of CD-based design for high ROS may usher in new prospects and challenges for high efficiency and stability of PDT and anticancer therapy. In conclusion, we have provided perspectives and challenges of the future development of CD s.

DFT guided substitution effect on azomethine reactive center in newly synthesized Schiff base aromatic scaffolds; syntheses, characterization, single crystal XRD, Hirshfeld surface and crystal void analyses

This paper aims to unfold the effect of substitution (ring A & B) on reactivity of newly synthesized crystalline azomethine linked aromatic compounds/Schiff bases (3a-c). Condensation reaction between 2-iodo-4-chloro substituted aniline with various suitably substituted aromatic aldehydes under acidic catalyzed reaction conditions gave crystalline compounds (3a-c) in good yields. The synthesized compounds were initially investigated in the solid state by single crystal X-ray crystallography besides other structural characterizations. Possible reactivity of azomethine pharmacophore is explained based on the electronic features of attached substituents on the aromatic rings A and B. DFT calculations further backed up the reactivity profile translated for compounds (3a-c) based on electronic grounds, while mechanistic investigation for further chemical reactivity is unfolded via frontier molecular orbital calculations and transition state predictions. Prominent nucleophilic character based on DFT study has been attributed to the halo i,e., -Cl and -I substituents on aromatic ring (ring A) in all the synthesized derivatives (3a-c) with pronounced effect in 3c due to added nucleophilic behavior depicted by cyano substitution in ring B. However, HOMO orbital energy values for (3a-c) predict electron donor behavior of substituents (-CH3, -N(CH3)2, -C=N) on ring B with higher donation capacity predicted for 3b, thus indicating its oxidation in possible chemical transformations. Hirshfeld surface analysis revealed the prevalence of potential van der Waals interactions and hydrogen bonding as major intermolecular interactions in their (3a-c) crystal packings. In addition, crystal void analyses depicted high mechanical stabilities for (3a-c) due to absence of large cavities in their crystal packings. Moreover, reaction scope guided by the joint DFT and electronic explanations for the effect of substituents used on azomethine linkage has also been proposed/predicted as part of the study.

Enhanced SHG performance of Cd 2+ doped DAST crystal featuring charge exchange owing metal ion-organic ligand for NLO applications

The slow evaporation solution (SEST) technique was used to grow a CdSO4 (5 %) doped DAST (CdS5-DAST) single crystal. The structural properties of the grown CdS5-DAST single crystal were investigated using single crystal X-ray Diffraction (SXRD) analysis. The SXRD data reveals that the CdS5-DAST crystal is non-centrosymmetric with a monoclinic (Cc) space group. The existence of a metal–organic 5 % of CdSO4 in DAST was affirmed by energy dispersive spectroscopy analysis (EDAX). The optical property of the grown single crystal was investigated by a UV–vis-NIR spectrometer, which showed the absorption cut-off wavelength is 380 nm. As a result, the electronic transition from non-bonding molecular orbital (ground) states to antibonding molecular orbital (excited) states corresponds to the absorption λ maximum. The energy (ΔE) requirement is small enough for electrons to transition from n-π* states. The optical bandgap (Eg), refractive index and extinction coefficient of the CdS5-DAST single crystal are calculated. As a result, crystals have an optical bandgap of 2.1 eV. Cd2+ doped DAST crystal enhances SHG performance significantly, owing to charge exchange facilitated by the metal ion-organic ligand and electron density. The grown CdS5-DAST crystal has a best SHG response and compared to the some organic NLO crystals. The PL spectrofluorometer study substantiates that green emission features at a wavelength of 527 nm. TG-DTA was being used to analyze the thermal characteristics of the crystal was thermally stable up to 259.95 °C.

Size Engineering of Trap Effects in Oxidized and Hydroxylated ZnSe Quantum Dots.

Environmentally friendly blue-emitting ZnSe quantum dots (QDs) are in high demand for next-generation light-emitting devices. Yet, they suffer longstanding optical instability issues under aerobic conditions. Herein, we have demonstrated the existence of oxidization or hydroxylation on the QD surface when QDs are subjected to oxygen exposure, which potentially introduces highly localized in-gap states. Those states result in a dense number of surface-related, weak-intensity "dark" exciton states at the emission edge. Remarkably, there exists a critical diameter (Dc ≈ 8.5 nm) at which the deepest trap level reaches resonance with the highest occupied molecular orbital state. Beyond this critical diameter, the effects of those trap states are minimized, and the emission edge is dominated by high-intensity, bulk-to-bulk-like "bright" exciton states. The present work provides a novel strategy for designing highly stable QD emitters via size engineering, which are broadly applicable to other closely related QD systems.

Modulating Non‐Radiative Deactivation via Acceptor Reconstruction to Expand High‐Efficient Red Thermally Activated Delayed Fluorescent Emitters

AbstractThe development of high‐efficient red thermally activated delayed fluorescent (TADF) materials is crucial to expanding their applications. Here, the acceptor reconstruction strategies of acceptor bonding and acceptor fusing in donor–acceptor‐type materials to modulate their nonradiative deactivation process and emission color for expanding high‐efficient red TADF emitters are presented. They are applied to design novel red TADF emitters TXO‐b‐TPA and TXO‐f‐TPA based on non‐red thioxanthone oxide (TXO) acceptor. Compared to TXO‐based emitter TXO‐TPA, these acceptor reconstruction strategies enable red‐shifted (48–88 nm) and efficient red TADF emission (600–640 nm). Their radiative and nonradiative transition processes can be modulated by the different molecular orbital and excited state distributions based on their acceptor structural differences, which results in a dramatic enhancement of their organic light‐emitting diode (OLED) device efficiencies from 1.21/3.63% (TXO‐f‐TPA) to 20.9% (TXO‐b‐TPA). These results confirm that the acceptor reconstruction strategies provide a viable solution for overcoming the limitations of previous red TADF emitters. Moreover, the retrieval of reported TADF materials can further demonstrate that these acceptor reconstruction strategies can be transferrable to more non‐red TADF materials to expand high‐efficient red‐shift and/or red TADF materials.

Rapid analysis of quinoxalines in feeds by a fluorescence sensor based on tetraphenylmethane porous organic framework membrane

In this work, a tetraphenylmethane porous organic framework (TPOF) membrane was prepared by mixing fluorescent TPOF into poly (vinylidene fluoride) (PVDF). Combining the advantages of membrane and TPOF, the TPOF membrane exhibited a continuous porous structure, good flexibility, hydrophobic properties and excellent fluorescence performance. Owing to the remarkable selectivity towards quinoxalines, the TPOF membrane was used as a fluorescence sensor for rapid quinoxalines analysis. The mechanism of the TPOF selectivity was studied by density functional theory (DFT) calculation experiments. Compared to other growth promoting drugs, the lowest unoccupied molecular orbital (LUMO) energy state difference between TPOF and quinoxalines was the largest. The linear ranges for the determination of carbadox and olaquindox were 0.3–20.0 and 0.6–20.0 μmol/L with the correlation coefficients (R2) of 0.9904 and 0.9943, respectively. The limit of detection (LOD, S/N = 3) were 96 and 182 nmol/L, respectively. Furthermore, this fluorescence sensor was used for olaquindox determination in feed samples, and the recoveries were varied from 97.4% to 107.7%. The results obtained by the proposed fluorescence method showed a good agreement with that obtained from HPLC method. Overall, this fluorescence sensor has been confirmed excellent performance in the quinoxalines analysis, which reveals extensive application in rapid residual quinoxalines analysis in feed samples.