Search Results (339)

A novel near-infrared (NIR) squaraine-based chemosensor, SQ-68, has been designed and synthesized for the sensitive and selective detection of Cu²⁺ and Ag⁺ ions, offering a compact solution for multi-analyte sensing. SQ-68 demonstrates high selectivity, with its performance influenced by the solvent environment: It selectively detects Cu²⁺ in acetonitrile and Ag⁺ in an ethanol–water mixture. Upon binding with either ion, SQ-68 undergoes significant absorption changes in the NIR region, accompanied by visible color changes, enabling naked-eye detection. Spectroscopic studies confirm a 1:1 binding stoichiometry with both Cu²⁺ and Ag⁺, accompanied by hypochromism. The detection limits are 0.09 μM for Cu²⁺ and 0.38 μM for Ag⁺, supporting highly sensitive quantification. The sensor’s practical applicability was validated in real water samples (sea, lake, and tap water), with recovery rates ranging from 73–95% for Cu²⁺ to 59–99% for Ag⁺. These results establish SQ-68 as a reliable and efficient chemosensor for environmental monitoring and water quality assessment. Its dual-analyte capability, solvent-tunable selectivity, and visual detection features make it a promising tool for rapid and accurate detection of heavy metal ions in diverse aqueous environments. Full article

Background/Objective: Thrombosis is the leading cause of graft failure and immediate hysterectomy following uterus transplantation (UTx). Currently, there is no standardized method for real-time assessment of UTx graft perfusion. This feasibility study aims to evaluate the utility of a near-infrared spectroscopy (NIRS) probe for non-invasive monitoring of local cervical tissue oxygenation (StO₂) during UTx. As proof-of-concept for the NIRS device, cervical StO₂ was also measured during non-donor hysterectomy and bilateral salpingo-oophorectomy to establish its capacity to reflect perfusion changes corresponding to vascular ligation. Methods: The ViOptix T. Ox Tissue Oximeter NIRS probe was attached to four uterine cervices during hysterectomy procedures and three separate donor cervices during UTx. Real-time StO₂ measurements were recorded at critical surgical steps: baseline, ovarian vessel ligation, contralateral ovarian vessel ligation, uterine vessel ligation, contralateral uterine vessel ligation, and colpotomy for hysterectomy; donor internal iliac vein anastomosis to recipient external iliac vein, donor internal iliac artery anastomosis to recipient external iliac artery, contralateral donor internal iliac vein anastomosis to recipient external iliac vein, contralateral donor internal iliac artery anastomosis to recipient external iliac artery, and donor and recipient vagina anastomosis for UTx. Results: During hysterectomy, average StO₂ levels sequentially decreased: 70.2% (baseline), 56.7% (ovarian vessel ligation), 62.1% (contralateral ovarian vessel ligation), 50.5% (uterine vessel ligation), 35.8% (contralateral uterine vessel ligation), and 8.5% (colpotomy). Conversely, during UTx, StO₂ progressive increased with each anastomosis: 8.9% (internal iliac vein- external iliac vein), 27.9% (internal iliac artery-external iliac artery), 56.9% (contralateral internal iliac vein-contralateral external iliac vein), 65.9% (contralateral internal iliac artery-contralateral external iliac artery), and 65.2% (vaginal anastomosis). Conclusions: The inverse correlation between StO₂ and vascular ligation during hysterectomy and the progressive rise in StO₂ during UTx suggests that cervical tissue oximetry may serve as a non-invasive modality for monitoring uterine graft perfusion. Further studies are warranted to determine whether these devices complement current assessments of uterine graft viability and salvage thrombosed grafts. Full article

Photodynamic therapy (PDT) using indocyanine green (ICG) has gained attention as an adjunctive treatment for periodontitis due to its antimicrobial and anti-inflammatory properties and its ability to penetrate deep periodontal tissues via near-infrared light activation. We aimed to evaluate the clinical and microbiological efficacy of ICG-mediated PDT as an adjunct to conventional periodontal therapy in patients with periodontitis based on data from randomized controlled trials (RCTs). A systematic search of PubMed, Embase, Scopus, and the Cochrane Library was conducted to identify randomized controlled trials (RCTs) exclusively investigating ICG-PDT in periodontitis based on predefined eligibility criteria. Studies were selected based on predefined inclusion criteria, and methodological quality was assessed using a 14-point scoring system. Data were extracted on clinical outcomes (e.g., probing depth, clinical attachment level) and microbiological changes. Sixteen RCTs met the inclusion criteria. Most studies reported improvements in probing depth, clinical attachment level, and microbial reduction following ICG-aPDT; however, some trials found no significant differences compared to control groups. These discrepancies may be attributable to variations in laser settings, ICG concentration, treatment frequency, or initial disease severity. Microbiological benefits included significant reductions in key periodontal pathogens. The therapy was well tolerated, with no adverse effects reported. However, variability in treatment protocols and limited long-term follow-up restricted the ability to draw definitive conclusions. ICG-mediated PDT is a promising, safe, and effective adjunct in periodontal therapy. Future trials should aim for protocol standardization and long-term outcome assessment to strengthen clinical guidance. Full article

Lymph node metastases are common in advanced ovarian cancer and are associated with poor prognosis. Accurate intraoperative identification of lymph node metastases remains a challenge in ovarian cancer surgery due to the lack of tumor-specific intraoperative imaging tools. Here, we developed a gonadotropin-releasing hormone receptor (GnRHR)-targeted near-infrared (NIR) fluorescent probe, GnRHa-PEG-Rh760, through conjugation of a GnRH analog peptide with the Rh760 fluorophore and polyethylene glycol (PEG). A non-targeted probe (PEG-Rh760) served as control. In mouse models of subcutaneous xenografts, peritoneal and lymph node metastases derived from ovarian cancer cells, GnRHa-PEG-Rh760 showed superior tumor-specific accumulation. NIR fluorescence imaging revealed strong fluorescence signals localized to primary tumors, peritoneal lesions, and metastatic lymph nodes with no off-target signals in normal lymph nodes. The spatial co-localization between the NIR fluorescence of GnRHa-PEG-Rh760 and tumor-derived bioluminescence clearly confirmed the probe’s target specificity. GnRHa-PEG-Rh760 mainly accumulated in the tumor and liver and was gradually cleared at 96 h post-injection. The retention of fluorescence signals in normal ovary tissue further validated GnRHR-mediated binding of the probe. Notably, GnRHa-PEG-Rh760 exhibited excellent biocompatibility with no observed systemic toxicity as evidenced by hematologic and histopathologic analyses. These data demonstrate the potential of GnRHa-PEG-Rh760 as an intraoperative imaging agent, providing real-time fluorescence imaging guidance to optimize surgical precision. This study highlights the value of receptor-targeted molecular imaging probes in precision cancer surgery. Full article

Background: Rectal cancer (RC) patients with a clinical complete response (cCR) after neoadjuvant chemoradiotherapy (nCRT) may qualify for a watch-and-wait (W&W) approach. However, a 20–30% local tumor regrowth rate highlights challenges in identifying true responders. This study explores markers for future near-infrared fluorescence tumor imaging by endoscopy to differentiate responders and the effect of nCRT on their expression. Methods: RC samples (n = 51) were collected from both pre-treatment biopsies and corresponding post-treatment surgical specimens. Samples were categorized by treatment response and determined using tumor regression grade (TRG) scoring. Immunohistochemistry assessed the expression of CEA, EpCAM, EGFR, and c-MET in tumors and adjacent normal tissues. Expression levels were quantified using H-scores (0–3), combining the percentage and intensity of stained cells. Pre- and post-treatment H-scores were compared to evaluate the impact of nCRT. Results: CEA, EpCAM, and c-MET were overexpressed in tumor tissue as compared to adjacent healthy mucosa in 100% (51/51), 98.4% (50/51), and 92% (47/51) of tumor biopsies, respectively, while EGFR showed no overexpression. A tumor-to-normal (T/N) ratio ≥ 2 was considered sufficient for differentiation in molecular fluorescence imaging. In pre-treatment biopsy samples, c-MET showed the highest T/N expression ratio (53% of the samples ≥ 2), followed by CEA (26.3%) and EpCAM (16%). Following nCRT treatment, CEA and c-MET maintained a ≥ 2 differential expression in 45% of all samples, whereas EpCAM exhibited this difference in only 9.2% of cases. Neoadjuvant therapy even significantly improved the T/N expression ratio for CEA and c-MET (p < 0.01) and EpCAM (p < 0.05), while EGFR expression remained lower than adjacent normal tissue. Significant increases in all marker expressions were observed in minimal responders (TRG4/5, p < 0.01–0.001), while near-complete responders (TRG2) exhibited non-significant changes in CEA, c-MET, and EGFR expression. Conclusions: c-MET and CEA emerged as optimal tumor imaging targets, showing sustained differential expression after nCRT. In vivo fluorescence-guided endoscopy using probes against these markers could play a role in future clinical decision-making. Full article

Near-infrared (NIR) rhodamine dyes are pivotal for bioimaging due to the minimal tissue interference. Yet, their rational design is hindered by unreliable computational methods for excited-state property prediction. We benchmarked the time-dependent density functional theory (TDDFT) with the linear-response (LR) and state-specific (SS) solvation models across five functionals (CAM-B3LYP, M06-2X, ωB97X-D, B3LYP, MN15) and optimized the ground/excited states for 42 rhodamine derivatives. A robust linear calibration framework was established by connecting the computed and experimental wavelengths, which was rigorously validated through six-fold cross-validation. The key metrics included the mean absolute error (MAE) and R² to assess the prediction robustness. CAM-B3LYP combined with LR solvation achieved the highest accuracy (absorption: MAE = 6 nm, R² = 0.94; emission: MAE = 12 nm, R² = 0.72). By integrating the TDDFT with a calibrated linear-response solvation model, we achieved sub-12 nm accuracy in predicting the NIR fluorescence peaks. This framework enabled the rational design of nine novel rhodamine derivatives with emissions beyond 700 nm, offering a paradigm shift in bioimaging probe development. Full article

With the increasing prevalence of plastic pollution, understanding its impact on soil nematodes is crucial for environmental sustainability and food security. Traditional fluorescence-based probes have the limitations of high background noise and interference from autofluorescence. In this study, the luminous upconverted NaYF4:Yb³⁺/Er³⁺ nanoparticles acted as high-sensitivity probes for real-time visualization of ingestion and biodistribution of polystyrene microplastics (PS-MPs) and nanoplastics (PS-NPs) in Caenorhabditis elegans. The novel probes enabled efficient near-infrared-to-visible light conversion. This approach improved the precision of nano- and microplastic detection in biological tissues. Microscopic imaging revealed that the probes effectively distinguished size-dependent plastic distribution patterns, with microplastics remaining in the digestive tract, whereas nanoparticles penetrated intestinal walls and entered systemic circulation. Quantitative fluorescence analysis confirmed that PS-NPs exhibited higher bioavailability and deeper tissue penetration, providing crucial insights into plastic behavior at the organismal level. The different toxicities of PS-NPs and PS-MPs were further confirmed by measurement of the locomotor impairments and the physiological disruptions. These findings emphasize the broader applications of upconverted nanoparticles as advanced bio-imaging probes, offering a sensitive and non-invasive tool for tracking pollutant interactions in environmental and biological systems. Full article

Peroxynitrite (ONOO⁻) is a reactive nitrogen species (RNS) that plays pivotal roles in various physiological and pathological processes. The recent literature has seen significant progress in the development of highly sensitive and selective fluorescent probes applicable for monitoring ONOO⁻ dynamics in live cells and a variety of animal models of human diseases. However, the clinical applications of those probes remain much less explored. This review delves into the biological roles of ONOO⁻ and summarizes the design strategies, sensing mechanisms, and bioimaging applications of near-infrared (NIR), long-wavelength, two-photon, and ratiometric fluorescent probes modified with a diverse range of functional groups responsive to ONOO⁻. Furthermore, we will discuss the remaining problems that prevent the currently developed ONOO⁻ probes from translating into clinical practice. Full article

A flash smelting furnace operation is based on the exothermic reduction of copper concentrates in the combustion shaft, and these reactions occur at high temperatures (1250–1350 °C), where flame control is fundamental to optimizing copper reduction. Furthermore, inherent physicochemical reactions of the reduction process have been shown to emit spectral lines in the visible-near infrared spectrum (250–900 nm). Thus, an optoelectronic sensor prototype is proposed and developed for flame measurements of an industrial copper concentrate flash smelting furnace. The sensor system is composed of a high-temperature optical fiber probe, which functions as a waveguide to capture the emitted flame radiation and a visible-near infrared spectrometer. From the measured radiation, flame temperature and flame dynamics are analyzed. Flame temperature is estimated using the two-wavelength temperature estimation method, and flame dynamics are defined as variations in the total emissive power, which are studied in the time and frequency domain via the Fourier Transform method. These combustion dynamics are then used to create a flame instability index, which is used to characterize the flame combustion quality. The combination of this index and sensor platform provides a powerful tool to aid in proper flame control. Full article

Background/Objectives: This study evaluated the role of a discrete multi-wavelength near-infrared spectroscopic (DMW-NIRS) imaging device for rapid breast lesion differentiation. Methods: A total of 62 women (mean age, 49.9 years) with ultrasound (US)-guided biopsy-confirmed breast lesions (37 malignant, 25 benign) were included. A handheld probe equipped with five pairs of light-emitting diodes (LEDs) and photodiodes (PDs) measured lesion-to-normal tissue (L/N) ratios of four chromophores, THC (Total Hemoglobin Concentration), StO₂, and the Tissue Optical Index (TOI: log10(THC × Water/Lipid)). Lesions were localized using US. Diagnostic performance was assessed for each L/N ratio, with subgroup analysis for BI-RADS 4A lesions. Two adaptive BI-RADS models were developed: Model 1 used TOI_L/N thresholds (Youden index), while Model 2 incorporated radiologists’ reassessments of US findings integrated with DMW-NIRS results. These models were compared to the initial BI-RADS assessments, conducted by breast-dedicated radiologists. Results: All L/N ratios significantly differentiated malignant from benign lesions (p < 0.05), with TOI_L/N achieving the highest AUC-ROC (0.901; 95% CI: 0.825–0.976). In BI-RADS 4A lesions, all L/N ratios except Lipid significantly differentiated malignancy (p < 0.05), with TOI_L/N achieving the highest AUC-ROC (0.902; 95% CI: 0.788–1.000). Model 1 and Model 2 showed superior diagnostic performance (AUC-ROCs: 0.962 and 0.922, respectively), significantly outperforming initial BI-RADS assessments (prospective AUC-ROC: 0.862; retrospective AUC-ROC: 0.866; p < 0.05). Conclusions: Integrating DMW-NIRS findings with US evaluations enhances diagnostic accuracy, particularly for BI-RADS 4A lesions. This novel device offers a rapid, non-invasive, and efficient method to reduce unnecessary biopsies and improve breast cancer diagnostics. Further validation in larger cohorts is warranted. Full article

The early detection of breast cancer, particularly in dense breast tissues, faces significant challenges with traditional imaging techniques such as mammography. This study utilizes a Near-infrared Scan (NIRscan) probe and an advanced convolutional neural network (CNN) model to enhance tumor localization accuracy and efficiency. CNN processed data from 133 breast phantoms into 266 samples using data augmentation techniques, such as mirroring. The model significantly improved image reconstruction, achieving an RMSE of 0.0624, MAE of 0.0360, R² of 0.9704, and Fuzzy Jaccard Index of 0.9121. Subsequently, we introduced a multitask CNN that reconstructs images and classifies them based on depth, length, and health status, further enhancing its diagnostic capabilities. This multitasking approach leverages the robust feature extraction capabilities of CNNs to perform complex tasks simultaneously, thereby improving the model’s efficiency and accuracy. It achieved exemplary classification accuracies in depth (100%), length (92.86%), and health status, with a perfect F1 Score. These results highlight the promise of NIRscan technology, in combination with a multitask CNN model, as a supportive tool for improving real-time breast cancer screening and diagnostic workflows. Full article

Coffee bean sorting is currently based primarily on visual appearance and near-infrared techniques that probe the bean’s skin. However, sorting based on compositional differences has significant potential to optimize the roasting process. We present a novel coffee bean sorting method using terahertz (THz) spectroscopy, which effectively penetrates both green and roasted beans. Our findings show that the optical properties of coffee beans at THz frequencies are primarily governed by internal moisture levels. To demonstrate industrial feasibility, we implement a robot-guided THz sensing system capable of scanning beds of beans for automated sorting. More broadly, our results confirm the potential of THz technology for moisture content analysis across various applications. Full article

We investigate the resonant characteristics of planar surfaces and distinct edges of structures with the excitation of phonon-polaritons. We analyze two materials supporting phonon-polariton excitations in the mid-infrared spectrum: silicon carbide, characterized by an almost isotropic dielectric constant, and hexagonal boron nitride, notable for its pronounced anisotropy in a spectral region exhibiting hyperbolic dispersion. We formulate a theoretical framework that accurately captures the excitations of the structure involving phonon-polaritons, predicts the response in scattering-type near-field optical microscopy, and is effective for complex resonant geometries where the locations of hot spots are uncertain. We account for the tapping motion of the probe, perform analysis for different heights of the probe, and demodulate the signal using a fast Fourier transform. Using this Fourier demodulation analysis, we show that light enhancement across the entire apex is the most accurate characteristic for describing the response of all resonant excitations and hot spots. We demonstrate that computing the demodulation orders of light enhancement in the microscope probe accurately predicts its imaging. Full article

H₂O₂ plays an important role in oxidative damage and redox signaling. Studies have shown that abnormal levels of H₂O₂ are closely related to the development of cancer. The levels of H₂O₂ in tumor cells are higher than in normal cells. Thus, it is of great importance to develop a fluorescent probe to monitor the level of H₂O₂ in vivo. This work reports a new biotin-guided NIR fluorescent probe, Bio-B-Cy, consisting of boronic acid ester as a H₂O₂-recognition site and biotin as a tumor binding site, which accelerates the fluorescence response to H₂O₂ in vivo. Bio-B-Cy exhibits good sensitivity and selectivity toward H₂O₂. In addition, Bio-B-Cy shows a dose-dependent response to H₂O₂ and the detection limit is 0.14 μM. We further demonstrate that Bio-B-Cy could successfully detect the H₂O₂ in biotin receptor-positive cancer cells and tumor tissues. Based on the results, Bio-B-Cy has the potential to serve as an efficient tool for early diagnosis of cancer. Full article

Near-infrared (NIR) light is a promising tool for biomedical imaging and therapy, offering excellent tissue penetration, low scattering, and minimal biological fluorescence interference. An NIR-II optical range of 900–1880 nm with reduced background interference is particularly useful for disease diagnosis and treatment. Probes based on organic molecules are gaining attention for their structural flexibility and stable performance. Organic molecular aggregates, such as J-aggregates, H-aggregates, and aggregation-induced emission (AIE)-aggregates, exhibit unique optical properties like tunable spectral shifts, improved photostability, and higher absorption and fluorescence quantum yields. This mini review briefly discusses the advancements in NIR-II optical imaging and therapy technologies, focusing on the classification, formation mechanisms, and applications of organic molecular aggregates in disease diagnosis and treatment, offering a theoretical foundation and practical guidance for future research. Full article