Near-infrared Research Articles

Trackable Liposomes for In Vivo Delivery Tracing toward Personalized Medicine Care under NIR Light on Skin Tumor.

We report an near-infrared (NIR)-trackable and therapeutic liposome with skin tumor specificity. Liposomes with a hydrodynamic diameter of ∼20 nm are tracked under the vein visualization imaging system in the presence of loaded paclitaxel and NIR-active agents. The ability to track liposome nanocarriers is recorded on the tissue-mimicking phantom model and in vivo mouse veins after intravenous administration. The trackable liposome delivery provides in vitro and in vivo photothermal heat (∼40 °C) for NIR-light-triggered area-specific chemotherapeutic release. This approach can be linked with a real-time vein-imaging system to track and apply area-specific local heat, which hitchhikes liposomes from the vein and finally releases them at the tumor site. We conducted studies on mice skin tumors that indicated the disappearance of tumors visibly and histologically (H&E stains). The ability of nanocarriers to monitor after administration is crucial for improving the effectiveness and specificity of cancer therapy, which could be achieved in the trackable delivery system.

The GAPS Programme at TNG LVI. Characterisation of the low-density gas giant HAT-P-67 b with GIARPS

Context is one of the lowest-density gas giants known to date, making it an excellent target for atmospheric characterisation through the transmission spectroscopy technique. Aims . In the framework of the GAPS large programme, we collected four transit events of \, with the aim of studying the exoplanet atmosphere and deriving the orbital projected obliquity. Methods . We exploited the high-precision GIARPS (GIANO-B + HARPS-N) observing mode of the Telescopio Nazionale Galileo (TNG) along with additional archival TESS photometry to explore the activity level of the host star. We performed transmission spectroscopy, both in the visible (VIS) and in the near-infrared (NIR) wavelength range, and we analysed the RML effect when fitting both the radial velocities and the Doppler shadow. Based on the TESS photometry, we redetermined the transit parameters of Results . By modelling the RML effect, we derived a sky-projected obliquity of ($2.2 circ $, indicating an aligned planetary orbit. The chromospheric activity index $ prime HK $, the CCF profile, and the variability in the transmission spectrum of the H$ line suggest that the host star shows signatures of stellar activity and/or pulsation. We found no evidence of atomic or molecular species in the optical transmission spectra, with the exception of pseudo-signals corresponding to Cr I Fe I H$ Na I and Ti I . In the NIR range, we found an absorption signal of the triplet of $<!PCT!> (19.0sigma ), corresponding to an effective planetary radius of sim 3 $R (where $R 2 $R which extends beyond the planet's Roche lobe radius. Conclusions . Owing to the stellar variability and the high uncertainty of the model, we could not confirm the planetary origin of the signals found in the optical transmission spectrum. On the other hand, we were able to confirm previous detections of the infrared triplet, providing a 19.0sigma detection. Our finding indicates that the planet's atmosphere is evaporating.

2D-3D heterostructure of PtS2-x/Ga2O3 and their band alignment studies for high performance and broadband photodetector.

For deep ultraviolet (UV-C) photodetectors, Gallium oxide (Ga2O3) is a suitable candidate owing to its intrinsic ultra-wide band gap and high stability. However, its detection is limited within the UV-C region, which restricts it to cover a broad range, especially in visible and near-infrared (NIR) region. Therefore, constructing a heterostructure of Ga2O3 with an appropriate material having a narrow band gap is a worthwhile approach to compensate for it. In this category, PtS2 group-10 transitional metal dichalcogenide (TMDC) stands at the top owing to its narrow band gap (0.25-1.65 eV), high mobility, and stability for heterostructure synthesis. Moreover, heterostructure with Ga2O3 sensing in UV and PtS2 broad response in visible and IR range can broaden the spectrum from UV to NIR and to build broadband photodetector. In this work, we fabricated a 2D-3D PtS2-x/Ga2O3 heterostructure based broadband photodetector with detection from UV-C to NIR region. In addition, the PtS2-x/Ga2O3 device shows a high responsivity of 38.7 AW 1 and detectivity of 4.8×1013 Jones under 1100 nm light illumination at 5V bias. A fast response of 90 ms /86 ms illustrates the device's fast speed. An interface study between the PtS2-x and Ga2O3 was conducted using X-ray photoelectron spectroscopy and Ultraviolet photoelectron spectroscopy (UPS) which confirmed type-I band alignment. Finally, based on their band alignment study, a carrier transport mechanism was proposed at the interface. This work offers a new opportunity to fabricate large-area high-performance 2D-3D heterostructures based photodetectors for future optoelectronics devices.

Synergistic luminescent radicals and precursors as type-I photosensitizers for near-infrared fluorescence-guided tumor therapy

Near-infrared (NIR) fluorescence-guided photodynamic therapy (PDT) shows great potential as a cancer treatment modality. However, its application in solid tumors is limited by the scarcity of NIR molecules and the oxygen dependence of conventional photosensitizers. Here, two novel radical nanoparticles (TTM-3PDMAC:HTTM-3PDMAC@NPs and TTM-PDMAC:HTTM-PDMAC@NPs) are developed as type-I photosensitizers by combining luminescent radicals and their precursors. The unique encapsulation of these nanoparticles effectively addresses the limitations of radicals being insoluble and non-fluorescent in water, thus preserving the NIR emission of the radicals. Notably, the superoxide radicals generated by these nanoparticles upon light irradiation have been demonstrated to originate from both the radicals and their precursors. In vivo experiments demonstrated that TTM-3PDMAC:HTTM-3PDMAC@NPs exhibit significant efficacy in treating hypoxic tumor with minimal side effects. Overall, this PDT strategy based on synergistic combination of luminescent radicals and precursors provides novel insights for achieving accurate and efficient PDT under NIR fluorescence guidance.

A Self-Delivery Nanodrug Simultaneously Inhibits COX-2/PGE2 Mediated Inflammation and Downregulates PD-L1 to Boost Photoimmunotherapy.

Phototherapy promotes anti-tumor immunity by inducing immunogenic cell death (ICD), However, the accompanying inflammatory responses also trigger immunosuppression, attenuating the efficacy of photo-immunotherapy. Herein, they co-assembled a cell-membrane targeting chimeric peptide C16-Cypate-RRKK-PEG8-COOH (CCP) and anti-inflammatory diclofenac (DA) to develop a nanodrug (CCP@DA) that both enhances the immune effect of phototherapy and weakens the inflammation-mediated immunosuppression. CCP@DA achieves cell membrane-targeting photodynamic and photothermal synergistic therapies to damage programmed death ligand 1 (PD-L1) and induce a strong ICD to activate anti-tumor response. Simultaneously, the released DA inhibits the cycoperoxidase-2 (COX-2)/prostaglandin E2 (PGE2) pathway in tumor cells to inhibit pro-tumor inflammation and further down-regulate PD-L1 expression to relieve the immunosuppressive microenvironment. CCP@DA significantly inhibitedtumor growth and inflammation both in vitro and in vivo, while maintaining a potent anti-tumor immune response. Additionally, it exhibits excellent anti-metastatic capabilities and prolongs mouse survival time with a single dose and low levels of near-infrared (NIR) light exposure. This work provides a valuable strategy to control the therapy-induced inflammation for high-efficiency photoimmunotherapy.

Evaluating resistance drilling and NIR spectroscopy for quantifying wood quality of young eucalypts grown in Guangxi province in southern China

Cost-effective, non-destructive means of estimating wood properties of eucalypts grown in Guangxi, China, were evaluated using near infrared (NIR) spectroscopy and resistance drilling. For this evaluation, wood samples for NIR analysis and resistance drill measurements were collected from 581 trees, representing eight plantation Eucalyptus taxa across five sites. The near infra-red (NIR) spectra collected from the 581 wood samples were analysed using existing calibrations for kraft pulp yield, cellulose content, hot water extractives and Klason lignin. These spectra and calibrations were effective in predicting over 60% of the variance in total carbohydrates and over 80% of the extractives and lignin values from independent laboratory analysis of a subset of 100 samples. Resistance drilling combined with software developed for processing the drill data proved to be a quick, low cost and effective means of quantifying wood density (as amplitude of the drill torque), stem diameter and bark thickness.

Simultaneous NIR Emission and Thermal Stability Enhancement in Garnet‐Type NIR Phosphors through the Synergistic Effect of Lattice Distortion and Enhanced Rigidity

AbstractEven though there have been significant advancements in the development of Cr3+‐activated near‐infrared (NIR) phosphors, the challenge still remains to develop highly efficient and thermally stable NIR phosphors. Here, the Ca4‐xZnxHfGe3O12:0.03Cr3+ solid solution phosphors with 834–806 nm NIR emission are constructed by substituting Zn2+ for Ca2+, thereby facilitating the formation of [ZnO6] luminescence site. The coexistence of [HfO6] and [Zn/CaO6] luminescence centers is confirmed through DFT calculation, time‐resolved photoluminescence (TRPL) spectroscopy, and low‐temperature‐photoluminescence (77 K) spectroscopy. The formation of [ZnO6] effectively resolves the issue of lattice mismatch between Cr3+ and Ca2+. Furthermore, the simultaneous enhancement of luminescence intensity and thermal stability is realized through a synergistic combination of lattice distortion and rigidity enhancement. By optimizing the substitution concentration of Cr3+, the internal quantum efficiency (IQE) of 92% and an external quantum efficiency (EQE) of 29% are finally achieved. Meanwhile, the thermal stability is also enhanced from 59%@400 K (x = 0) to 81%@400 K (x = 0.8). The developed NIR phosphor‐converted light‐emitting diodes (pc‐LEDs) exhibit promising prospects in the fields of security, biomedicine, non‐destructive testing and rapid identification.

Early feasibility study with an implantable near-infrared spectroscopy sensor for glucose, ketones, lactate and ethanol.

To evaluate the safety and performance of an implantable near-infrared (NIR) spectroscopy sensor for multi-metabolite monitoring of glucose, ketones, lactate, and ethanol. This is an early feasibility study (GLOW, NCT04782934) including 7 participants (4 with type 1 diabetes (T1D), 3 healthy volunteers) in whom the YANG NIR spectroscopy sensor (Indigo) was implanted for 28 days. Metabolic challenges were used to vary glucose levels (40-400 mg/dL, 2.2-22.2 mmol/L) and/or induce increases in ketones (ketone drink, up to 3.5 mM), lactate (exercise bike, up to 13 mM) and ethanol (4-8 alcoholic beverages, 40-80g). NIR spectra for glucose, ketones, lactate, and ethanol levels analyzed with partial least squares regression were compared with blood values for glucose (Biosen EKF), ketones and lactate (GlucoMen LX Plus), and breath ethanol levels (ACE II Breathalyzer). The effect of potential confounders on glucose measurements (paracetamol, aspartame, acetylsalicylic acid, ibuprofen, sorbitol, caffeine, fructose, vitamin C) was investigated in T1D participants. The implanted YANG sensor was safe and well tolerated and did not cause any infectious or wound healing complications. Six out 7 sensors remained fully operational over the entire study period. Glucose measurements were sufficiently accurate (overall mean absolute (relative) difference MARD of 7.4%, MAD 8.8 mg/dl) without significant impact of confounders. MAD values were 0.12 mM for ketones, 0.16 mM for lactate, and 0.18 mM for ethanol. The first implantable multi-biomarker sensor was shown to be well tolerated and produce accurate measurements of glucose, ketones, lactate, and ethanol. Clinical trial identifier: NCT04782934.

A Dual-Mode Near-Infrared Optical and Photoacoustic Imaging Agent Based on a Low Energy Absorbing Ytterbium Complex.

Near-infrared (NIR) luminescence and photoacoustic (PA) imaging have attracted increasing attention for the real-time monitoring of biological samples due to high sensitivity, resolution, and pronounced signal detection depth, respectively. For improved contrast, both techniques require imaging agents possessing high absorption in the red-NIR range. Herein, we took advantage of a ternary complex formed with the anionic ytterbium(III) tetrakis(2-thenoyltrifluoroacetonate) ([Yb(tta)4]-) and the cationic NIR-absorbing chromophore, 1,1'-diethyl-2,2'-dicarbocyanine (Cy+), to evaluate its potential to act as a dual-mode NIR luminescence and PA imaging agent. We demonstrated that, upon excitation with red-NIR light, Cy[Yb(tta)4] encapsulated into polystyrene nanoparticles is able to generate both NIR Yb3+ emission and a PA signal in an imaging experiment performed in a tissue-mimicking phantom.

Gold Nanoparticles Confined in Mesoporous Bioactive Glass for Periodontitis Therapy.

Periodontitis is a chronic disease caused by bacterial infection and is characterized with alveolar bone resorption. Bone regeneration in periodontitis remains a critical challenge because bacterial infection induced an unfavorable microenvironment for osteogenesis. Therefore, it is necessary to design proper therapeutic platforms to control bacterial infection and promote bone regeneration. Herein, mesoporous bioactive glass (MBG) with different pore sizes (3.0, 4.3, and 12.3 nm) was used as an in situ reactor to confine the growth of gold nanoparticles (Au NPs), forming MBG@Au hybrids which combine the osteoconductivity of MBG and antibacterial properties of Au NPs. Upon near-infrared (NIR) irradiation, the MBG@Au NPs showed efficient antibacterial properties both in vitro and in vivo. Besides, the osteogenesis properties of MBG@Au also improved under NIR irradiation. Furthermore, the in vivo results demonstrated that MBG@Au can effectively promote alveolar bone regeneration and realize the healing of serious periodontitis.

Alkali metal ion passivation of lead-free perovskite film for high responsivity self-powered broadband photodetectors

All-inorganic lead-free bismuth-based perovskites have attracted great interest in the optoelectronic applications due to their low toxicity and excellent stability. However, the inherent polycrystalline (PC) of perovskite films suffers severe charge recombination due to the large numbers of trap density. Herein, high-quality Cs3Bi2I9 (CBI) PC thin films are prepared by solution process with alkali sodium (Na+) cation doping strategy, resulting large grain size and lower trap density. Afterward, the photoelectrochemical-type detectors based on Na+ doped CBI thin film is constructed for the first time. The photodetector displays a broadband photoresponse covering ultraviolet (UV), visible and near-infrared (NIR) ranges. Significantly, by precisely controlling Na+ doping concentration, the performance of photodetector can be largely enhanced with the highest responsivity of 53.38 mA/W and detectivity of 5.99 × 109 Jones without bias, and these results exceed the performance of most reported CBI PC thin film based photodetectors. In addition, the photodetector exhibits an obvious increase in photoresponse and outstanding photo-stability after more than 150 on/off cycles. Finally, the mechanism of Na+ doping is further discussed. These results provide an outstanding example for the preparing high-quality CBI PC thin film and also demonstrate the great potential of CBI in the application of self-powered broadband photodetectors.

Fabrication of Rhenium Disulfide/Mesoporous Silica Core-Shell Nanoparticles for a pH-Responsive Drug Release and Combined Chemo-Photothermal Therapy.

A stimuli-responsive drug delivery nanocarrier with a core-shell structure combining photothermal therapy and chemotherapy for killing cancer cells was constructed in this study. The multifunctional nanocarrier ReS2@mSiO2-RhB entails an ReS2 hierarchical nanosphere coated with a fluorescent mesoporous silica shell. The three-dimensional hierarchical ReS2 nanostructure is capable of effectively absorbing near-infrared (NIR) light and converting it into heat. These ReS2 nanospheres were generated by a hydrothermal synthesis process leading to the self-assembly of few-layered ReS2 nanosheets. The mesoporous silica shell was further coated on the surface of the ReS2 nanospheres through a surfactant-templating sol-gel approach to provide accessible mesopores for drug uploading. A fluorescent dye (Rhodamine B) was covalently attached to silica precursors and incorporated during synthesis in the mesoporous silica walls toward conferring imaging capability to the nanocarrier. Doxorubicin (DOX), a known cancer drug, was used in a proof-of-concept study to assess the material's ability to function as a drug delivery carrier. While the silica pores are not capped, the drug molecule loading and release take advantage of the pH-governed electrostatic interactions between the drug and silica wall. The ReS2@mSiO2-RhB enabled a drug loading content as high as 19.83 mg/g doxorubicin. The ReS2@mSiO2-RhB-DOX nanocarrier's cumulative drug release rate at pH values that simulate physiological conditions showed significant pH responsiveness, reaching 59.8% at pH 6.8 and 98.5% and pH 5.5. The in vitro testing using HeLa cervical cancer cells proved that ReS2@mSiO2-RhB-DOX has a strong cancer eradication ability upon irradiation with an NIR laser owing to the combined drug delivery and photothermal effect. The results highlight the potential of ReS2@mSiO2-RhB nanoparticles for combined cancer therapy in the future.

Plasmon-Induced Ultrafast Hot Hole Transfer in Nonstoichiometric CuxInyS/CdS Heteronanocrystals.

Plasmonic semiconductors are promising candidates for developing energy conversion devices due to their tunable band gap, cost-effectiveness, and nontoxicity. Such materials exhibit remarkable capabilities for harvesting infrared photons, which constitute half of the solar energy spectrum. Herein, we have synthesized near-infrared (NIR) active CuxInyS nanocrystals and CuxInyS/CdS heterostructure nanocrystals (HNCs) to investigate plasmon-induced charge transfer dynamics on an ultrafast time scale. Employing femtosecond transient absorption spectroscopy, we demonstrate that upon exciting the HNCs with sub-band gap NIR photons (λ = 840 nm), the hot holes are generated in the valence band of plasmonic CuxInyS and transferred to the adjacent semiconductor. The decreased signal intensity and accelerated hole phonon relaxation dynamics for HNCs reveal efficient transfer of plasmon-induced hot carriers from CuxInyS to CdS under both 840 and 350 nm laser excitations, providing a pathway for enhanced carrier utilization. These findings shed light on the potential of ternary chalcogenides in plasmonic applications, highlighting efficient hot carrier extraction to adjacent semiconductors.

Electrospun photothermal tellurium nanosheet-loaded polycaprolactone/gelatin nanofibers to promote wound healing

Low-cost and biodegradable photothermal wound dressings with remarkable therapeutic effects are highly desirable for next-generation wound healing. Herein, we report an efficient photothermal wound dressing mat made of tellurium nanosheet (TeNS)-loaded electrospun polycaprolactone/gelatin (PCL/GEL) nanofibers. The TeNS-loaded PCL/GEL nanofibrous architectures showed antibacterial efficacy against Escherichia coli and Staphylococcus aureus of 87.68% and 94.57%, respectively. Under near-infrared (NIR) light illumination, they can facilitate cell proliferation as revealed by in vitro scratch assay. The results from in vivo skin wounds combined with tissue staining experiments further showed that the TeNS-loaded dressing could substantially promote wound healing under photothermal conditions. Using immunohistochemical analysis, we found that the TeNS-loaded PCL/GEL nanofibers [Formula: see text] NIR group have a high expression of specific antigens in epidermal growth factor (EGF) ([Formula: see text]) and endothelial cell adhesion molecule-31 (CD31, [Formula: see text]), verifying that the nanofibrous mat can stimulate EGF generation and microvessel proliferation. Furthermore, the PCL/GEL/Te[Formula: see text]NIR group has the lowest expression in endothelial cell adhesion molecule-68 (CD68, [Formula: see text]), suggesting that the nanofibrous mats have a high anti-inflammatory efficiency. Our work sheds light on the development of novel nonanti-inflammatory wound dressings via photothermal sterilization and the promotion of cell growth using two-dimensional (2D) nanosheets.

Prediction of cyanidin 3-rutinoside content in Michelia crassipes based on near-infrared spectroscopic techniques.

Currently the determination of cyanidin 3-rutinoside content in plant petals usually requires chemical assays or high performance liquid chromatography (HPLC), which are time-consuming and laborious. In this study, we aimed to develop a low-cost, high-throughput method to predict cyanidin 3-rutinoside content, and developed a cyanidin 3-rutinoside prediction model using near-infrared (NIR) spectroscopy combined with partial least squares regression (PLSR). We collected spectral data from Michelia crassipes (Magnoliaceae) tepals and used five different preprocessing methods and four variable selection algorithms to calibrate the PLSR model to determine the best prediction model. The results showed that (1) the PLSR model built by combining the blockScale (BS) preprocessing method and the Significance multivariate correlation (sMC) algorithm performed the best; (2) The model has a reliable prediction ability, with a coefficient of determination (R2) of 0.72, a root mean square error (RMSE) of 1.04%, and a residual prediction deviation (RPD) of 2.06. The model can be effectively used to predict the cyanidin 3-rutinoside content of the perianth slices of M. crassipes, providing an efficient method for the rapid determination of cyanidin 3-rutinoside content.

Theoretical investigation of energy levels and transitions for Ce iii with applications to kilonova spectra

ABSTRACT Doubly ionized cerium (Ce2+) is one of the most important ions to understand the kilonova spectra. In particular, near-infrared (NIR) transitions of Ce iii between the ground (5p6 4f2) and first excited (5p6 4f 5d) configurations are responsible for the absorption features around 14 500 Å. However, there is no dedicated theoretical studies to provide accurate transition probabilities for these transitions. We present energy levels of the ground and first excited configurations and transition data between them for Ce iii. Calculations are performed using the grasp2018 package, which is based on the multiconfiguration Dirac–Hartree–Fock and relativistic configuration interaction methods. Compared with the energy levels in the NIST data base (Kramida et al. 2024), our calculations reach the accuracy with the root-mean-square (rms) of 2732 or 1404 cm−1 (excluding one highest level) for ground configuration, and rms of 618 cm−1 for the first excited configuration. We extensively study the line strengths and find that the Babushkin gauge provides the more accurate values. By using the calculated gf values, we show that the NIR spectral features of kilonova can be explained by the Ce iii lines.

Longitudinal Extension of Double π-Helix Enables Near-Infrared Amplified Dissymmetry and Chiroptical Response.

Near-infrared (NIR) circularly polarized light absorbing or emitting holds great promise for highly sensitive and precise bioimaging, biosensing, and photodetectors. Aiming at designing NIR chiral molecular systems with amplified dissymmetry and robust chiroptical response, herein, we present a series of double π-helical dimers with longitudinally extended π-entwined substructures via Ullmann or Yamamoto homocoupling reactions. Circular dichroism (CD) spectra revealed an approximate linear bathochromic shift with the rising number of naphthalene subunits, indicating a red to NIR chiroptical response. Particularly, the terrylene diimide-entwined dimers exhibited the strongest CD intensities, with the maximal |Δε| reaching up to 393 M-1 cm-1 at 666 nm for th-TDI[2]; and a record-high chiroptical response (|ΔΔε|) between the neutral and dianionic species of 520 M-1 cm-1 at 833 nm for th-TDI[2]Cl was achieved upon further reduction to its dianionic state. Time-dependent density functional theory (TDDFT) calculations suggested that the pronounced intensification of the CD spectra originated from a simultaneous enhancement of both electric (μ) and magnetic (m) transition dipole moments, ultimately leading to an overall increase in the rotatory strength (R). Notably, the circularly polarized luminescence (CPL) brightness (BCPL) reached 77 M-1 cm-1 for th-TDI[2]Cl, among the highest values reported for NIR-CPL emitters. Furthermore, all chiral dianions exhibited excellent air stability under ambient conditions with half-life times of up to 10 days in N-methylpyrrolidone (NMP), which is significant for future biological applications and chiroptic switches.

Two-Site Occupation for Constructing Double Perovskite BaLaMgNbO6:Cr3+ Ultrabroadband NIR Phosphors.

Given the escalating significance of near-infrared (NIR) spectroscopy across industries, agriculture, and various domains, there is an imminent need to address the development of a novel generation of intelligent NIR light sources. Here, a series of Cr3+-doped BaLaMgNbO6 (BLMN) ultrabroadband NIR phosphor with a coverage range of 650-1300 nm were developed. The emission peak locates at 830 nm with a full width at half maximum of 210 nm. This ultrabroadband emission originates from the 4T2→4A2 transition of Cr3+ and the simultaneous occupation of [MgO6] and [NbO6] octahedral sites confirmed by low photoluminescence spectra (77-250 K), time-resolved photoluminescence spectra, and electron paramagnetic resonance spectra. The fluxing strategy improves the luminescence intensity and thermal stability of BLMN:0.02Cr3+ phosphors. The internal quantum efficiency (IQE) is 51%, external quantum efficiency (EQE) can reach 33%, and thermal stability can be maintained at 60%@100 °C. Finally, we successfully demonstrated the application of BLMN:Cr3+ ultrabroadband in the qualitative analysis of organic matter and food freshness detection.

Correction of the Effect of Humic Acids on the Fluorescence Detection of Polycyclic Aromatic Hydrocarbons by Combination Spectroscopy.

Polycyclic aromatic hydrocarbons (PAHs) are widely distributed in soil and water, but fluorescence spectroscopy for PAHs is often interfered with organic matter in the environment. The aim of this paper is to evaluate a correction method using combined spectral technology in an environment where humic acids and PAHs coexist. In the present work, humic acids and benzo[ghi]perylene were analyzed in various concentrations using fluorescence and near-infrared (NIR) spectroscopy from single and mixed samples. The NIR prediction model of humic acids in mixed samples was established based on synergy interval partial least squares, and the standard curve of fluorescence spectra for humic acids was established at 478 nm (characteristic wavelength of benzo[ghi]perylene). The fluorescence intensity of humic acids in the mixed sample was predicted from the content derived from the NIR spectra. The final correction was carried out by their exclusion from the fluorescence of the mixture at the same wavelength. The corrected fluorescence intensity was linearly correlated with the concentration of benzo[ghi]perylene with R2 = 0.8362, while R2 = 0.3538 before correction. These results give a new insight into the calibration modeling of the combined spectral method.

Rapid determination of residual pefloxacin in mutton based on hyperspectral imaging and data fusion

Non-destructive detection of veterinary drug residues in meat products is critical for ensuring food safety and human health. The feasibility of using visible near-infrared (Vis-NIR) and near-infrared (NIR) hyperspectral imaging (HSI) system combined with data fusion for the prediction of pefloxacin residues in mutton was investigated in this study. A partial least squares regression optimization model was developed by multivariate data processing methods. The results showed that the low-level fusion (LLF) produced better results with R2P = 0.907 and RMSEP = 0.462 as compared to individual data blocks. Furthermore, intermediate-level fusion (ILF) based on iterative retention of informative variables algorithm showed the best results with R2P = 0.940 and RMSEP = 0.375. Finally, the visualized distributions of Vis-NIR and NIR based on the optimal model combination were mapped. The results have demonstrated that a combination of HSI with data fusion may be applied to rapidly and non-destructively detect pefloxacin residues in mutton.