Colorimetric and fluorescent probes for cysteine detection: Applications in food safety and cellular imaging.

In this study, three BODIPY-based fluorescent probes were designed and synthesized. The ultraviolet-visible spectra, fluorescence spectra, smartphone color recognition application and bioimaging were utilized to evaluate the capacity of the probes. By comparing key parameters, BDP-SIN had optimal performances including fastest response (10 min), highest signal-to-noise ratio (815 times) and lowest limit of detection (LOD = 49 nM). The recovery rate ranged from 92.04 % to 103.25 %. Meanwhile, BDP-SIN was triumphantly employed for determination of Cys in different daily food samples. Moreover, the test strips and microporous filter membrane loaded with BDP-SIN were developed for the portable real-time visualization and quantitative detection of Cys in food samples, which the contents ranged from 0.27 µM to 0.49 µM. Besides, BDP-SIN could image Cys in the living cells and mice. The novelty of this work was that developed an effective tool for researching the roles of Cys in food industry and living organisms.

A dual-channel fluorescent probe targeting lysosomes for differential detection of Cys/Hcy and GSH: Applications in food, pharmaceutical analysis and bioimaging.

Thiols function as antioxidants in food, prolonging shelf life and enhancing flavor. Moreover, thiols are vital biomolecules involved in enzyme activity, cellular signal transduction, and protein folding among critical biological processes. In this paper, the fluorescent probe PYL-NBD was designed and synthesized, which utilized the fluorescent molecule pyrazoline, the lysosome-targeted morpholine moiety, and the sensing moiety NBD. Probe PYL-NBD was tailored for the recognition of biothiols through single-wavelength excitation, yielding distinct fluorescence emission signals: blue for Cys, Hcy, and GSH; green for Cys, Hcy. Probe PYL-NBD exhibited rapid reaction kinetics (<10 min), distinct fluorescence response signals, and low detection limits (15.7 nM for Cys, 14.4 nM for Hcy, and 12.6 nM for GSH). Probe PYL-NBD enabled quantitative determination of Cys content in food samples and L-cysteine capsules. Furthermore, probe PYL-NBD had been successfully applied for confocal imaging with dual-channel detection of biothiols in various biological specimens, including HeLa cells, zebrafish, tumor sections, and Arabidopsis thaliana.

Dual pH-responsive polypeptide nanoprobes for lysosomes enhanced bioimaging and tumor photothermal therapy under 1064 nm irradiation.

Cancer cell precise fluorescence imaging and following tumor photothermal therapy have garnered ongoing interest. Lysosomes in cancer cells in a typical acidic environment can be used for smart bioimaging, and intelligent NIR-II fluorescence probes are attractive for tumor phototheranostics. Here, we successfully synthesized a pH-responsive NIR-II fluorescent dye FPZ and the introduction of N-methylpiperazine moiety at the ring position in the dye-endowed FPZ with fluorescence enhancement under acidic response. A pH-sensitive amphiphilic polypeptide was selected as the carrier to prepare FPZ-PN nanoparticles, which could be disassembled under acidic stimulation for efficient drug delivery and enrichment, and its fluorescence was significantly restored and enhanced (fluorescence enhancement of about 4.2 times) because of the blockage of the photoinduced electron transfer process, which allowed for efficient NIR-II fluorescence imaging, especially the lysosomes in cancer cells. In addition, the nanoparticles exhibited great photostability and a significant photothermal effect, with a photothermal conversion efficiency reaching as high as 69.96 % when subjected to a 1064 nm laser irradiation, which can effectively kill tumor cells. Thus, this work provides a new effective strategy for designing smart-responsive nanomedicine systems for precise localization and tumor elimination.

Do probiotics and iron supplementation have any impact on element distribution in rat kidneys? - bioimaging by laser ablation inductively coupled plasma mass spectrometry.

This study investigates the influence of multistrain probiotics and iron supplementation on the distribution and interaction of trace elements in the kidneys of Wistar rats using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) bioimaging. Forty 6-week-old female Wistar rats were divided into five groups, each fed an AIN-93 M diet with varying additions or deficiencies of iron and probiotics, which included a control, an iron-deficient diet, an iron-deficient diet with probiotics, an iron-deficient diet with iron supplementation, and an iron-deficient diet with both probiotics and iron supplementation. The obtained two-dimensional maps of the distribution of elements reveal distinct locations of Cu, Fe, Mn, and Zn in specific tissues of rat kidneys. Specifically, Cu and Fe were co-localized in the renal cortex, while Zn was mostly absent from regions where Cu and Fe accumulated. Fe supplementation alone increased Fe in the renal cortex, while probiotics enhanced this effect, suggesting a synergistic role in Fe absorption. The total content of elements in the kidneys of all groups was determined after digestion: Cu 13.3-24.7 mg kg-1, Fe 218-509 mg kg-1, Mn 0.87-1.29 mg kg-1, and Zn 28.6-40.1 mg kg-1. Competitive interactions among Cu, Fe, and Zn were observed, with probiotics modulating their concentrations and distribution, highlighting their role in trace element homeostasis. Our research provides insights into the interactions between dietary supplements, probiotics, and trace element distribution in kidneys, paving the way for targeted nutritional interventions. This study highlights the need for further research on trace element functions in organisms and their impact on health.

Current Context of Designing Phototheranostic Cyclometalated Iridium (III) Complexes to Open a New Avenue in Cancer Therapy.

Photo-induced chemotherapy offers the best option for the selective treatment of cancer among all the prevailing modalities. Iridium (III) complexes, flourished with excellent photophysical and photochemical properties, have been considered to be superior for undergoing photo-responsive cancer therapy. Large Stokes shift, long-lived triplet excited state, photostability, and tuneable emission have rendered its excellence as a phototheranostic agent. In particular, the cyclometalated Ir (III) complexes and their respective nanoparticles have made a strong niche in the arena of cancer therapy. In recent years, Ir (III) based complexes have shown promising utilities as both imaging and therapeutic agents as well. Therefore, this review summarises the recent advances in the strategic designing of cyclometalated Ir(III) complexes to augment their phototheranostic applications in precision medicine.

Safety Evaluation of Carbon Dots in UM-UC-5 and A549 Cells for Biomedical Applications.

BACKGROUNG: The rising complexity and associated side effects of cancer treatments highlight the need for safer and more effective therapeutic agents. Carbon-based nanomaterials such as CDs have been gaining prominence for their unique characteristics, opening avenues for diverse applications such as fluorescence imaging, drug and gene transport, controlled drug delivery, medical diagnosis, and biosensing. Despite promising advancements in research, it remains imperative to scrutinize the properties and potential cytotoxicity of newly developed CDs, ensuring their viability for these applications. METHODS: We synthesized four N-doped CDs through a hydrothermal method. Cell viability assays were conducted on A549 and UM-UC-5 cancer cells at a range of concentrations and incubation times, both individually and with the chemotherapeutic agent 5-fluorouracil (5-FU). RESULTS: The obtained results suggest that the newly developed CDs exhibit suitability for applications such as bioimaging, as no significant impact on cell viability was observed for CDs alone.

Turn-On Fluorescence Probe for Cancer-Related γ-Glutamyltranspeptidase Detection.

The design and development of fluorescent materials for detecting cancer-related enzymes are crucial for cancer diagnosis and treatment. Herein, we present a substituted rhodamine derivative for the chromogenic and fluorogenic detection of the cancer-relevant enzyme γ-glutamyltranspeptidase (GGT). Initially, the probe is non-chromic and non-emissive due to its spirolactam form, which hinders extensive electronic delocalization over broader pathway. However, selective enzymatic cleavage of the side-coupled group triggers spirolactam ring opening, resulting in electronic flow across the rhodamine skeleton, and reduces the band gap for low-energy electronic transitions. This transformation turns the reaction mixture from colorless to intense pink, with prominent UV and fluorescence bands. The sensor's selectivity was tested against various human enzymes, including urease, alkaline phosphatase, acetylcholinesterase, tyrosinase, and cyclooxygenase, and showed no response. Absorption and fluorescence titration analyses of the probe upon incremental addition of GGT into the probe solution revealed a consistent increase in both absorption and emission spectra, along with intensified pink coloration. The cellular toxicity of the receptor was evaluated using the MTT assay, and bioimaging analysis was performed on BHK-21 cells, which produced bright red fluorescence, demonstrating the probe's excellent cell penetration and digestion capabilities for intracellular analytical detection. Molecular docking results supported the fact that probe-4 made stable interactions with the GGT active site residues.

Versatile Approaches of Quantum Dots in Biosensing and Imaging.

Cancer is considered a formidable global health threat, despite substantial strides in diagnosis, detection, and therapeutic strategies. Remarkable progress has been achieved in these realms, yet the survival rates for cancer patients have persisted at suboptimal levels over decades. Acknowledging the need to address the ongoing challenges in cancer survival rates, research efforts are being made to push the boundaries of innovation in diagnostic techniques, bioimaging, and drug delivery technologies. Over the past few years, nano(bio)technology-based approaches have been applied for biosensing and imaging applications to detect biochemical substances in various matrices. Among various nanoengineered particulates, quantum dots (QDs) have been recognized as versatile agents for these applications. QDs, often called artificial atoms, are characterized by the remarkable optical and electrical features which are essential for cytosensing, localized bioimaging and therapeutics. Here in this review, we have discussed various QDs as sensitive and selective agents for precise sensing and imaging of cancer cells. Both electrochemical and optical approaches have been used to describe the cytosensing detection methods. Furthermore, the bioimaging of malignant tumor cells and the drug delivery with therapeutic responses of QDs have also been highlighted. This review also lists the several kinds of QDs that are frequently used for such kinds of applications, such as carbon, graphene, zinc, and other types of hybrid-based QDs. Finally, to shed insight on prospective research, the advantages and potential of QDs are also highlighted. In this article, we also emphasize the limitations and address the difficulties associated with QDs in clinical applications in order to provide insights for potential solutions.

Silver Nanoparticles in Therapeutics and Beyond: A Review of Mechanism Insights and Applications.

Silver nanoparticles (NPs) have become highly promising agents in the field of biomedical science, offering wide therapeutic potential due to their unique physicochemical properties. The unique characteristics of silver NPs, such as their higher surface-area-to-volume ratio, make them ideal for a variety of biological applications. They are easily processed thanks to their large surface area, strong surface plasmon resonance (SPR), stable nature, and multifunctionality. With an emphasis on the mechanisms of action, efficacy, and prospective advantages of silver NPs, this review attempts to give a thorough overview of the numerous biological applications of these particles. The utilization of silver NPs in diagnostics, such as bioimaging and biosensing, as well as their functions in therapeutic interventions such as antimicrobial therapies, cancer therapy, diabetes treatment, bone repair, and wound healing, are investigated. The underlying processes by which silver NPs exercise their effects, such as oxidative stress induction, apoptosis, and microbial cell membrane rupture, are explored. Furthermore, toxicological concerns and regulatory issues are discussed, as well as the present difficulties and restrictions related to the application of silver NPs in medicine.

Co-Assembled Nanosystems Exhibiting Intrinsic Fluorescence by Complexation of Amino Terpolymer and Its Quaternized Analog with Aggregation-Induced Emission (AIE) Dye.

Aggregation-induced emission dyes (AIEs) have gained significant interest due to their unique optical properties. Upon aggregation, AIEs can exhibit remarkable fluorescence enhancement. These systems are ideal candidates for applications in bioimaging, such as image-guided drug delivery or surgery. Encapsulation of AIEs in polymeric nanocarriers can result in biocompatible and efficient nanosystems. Herein, we report the fabrication of novel nanoaggregates formulated by amino terpolymer and tetraphenylethylene (TPE) AIE in aqueous media. Poly(di(ethylene glycol) methyl ether methacrylate-co-2-(dimethylamino)ethylmethacrylate-co-oligoethylene glycol methyl ether methacrylate), P(DEGMA-co-DMAEMA-co-OEGMA) hydrophilic terpolymer was utilized for the complexation of the sodium tetraphenylethylene 4,4',4″,4‴-tetrasulfonate AIE dye. Fluorescence spectroscopy, physicochemical studies, and self-assembly in aqueous and fetal bovine serum media were carried out. The finely dispersed nanoparticles exhibited enhanced fluorescence compared to the pure dye. To investigate the role of tertiary amino groups in the aggregation phenomenon, the polymer was quaternized, and quaternized polymer nanocarriers were fabricated. The increase in fluorescence intensity indicated stronger interaction between the cationic polymer analog and the dye. A stronger interaction between the nanoparticles and fetal bovine serum was observed in the case of the quaternized polymer. Thus, P(DEGMA-co-DMAEMA-co-OEGMA) formulations are better candidates for bioimaging applications than the quaternized ones, presenting both aggregation-induced emission and less interaction with fetal bovine serum.

Polymeric nanoparticles loaded with vincristine and carbon dots for hepatocellular carcinoma therapy and imaging.

Chemotherapy for hepatoblastoma is limited by organ toxicity and poor outcomes, prompting the search for new, more effective treatments with minimal side effects. Vincristine sulfate, a potent chemotherapeutic, faces challenges due to P-glycoprotein-mediated resistance and its systemic toxicity. Nanoparticles offer a promising solution by improving pharmacokinetics, targeting tumor cells, thus reducing side effects. Moreover, the use of fluorescent nanomaterials is emerging in biomedical applications such as bioimaging, detection and therapies. This study describes a promising delivery system utilizing carbon dots encapsulated with vincristine in biodegradable polycaprolactone nanoparticles via a double emulsion technique. The fine characterization of these nanoparticles showed that they are spherical, uniformly sized with around 200 nm and exhibit excellent colloidal stability. Moreover, the release profile showed prolonged release for both vincristine and carbon dots. In vitro cell viability studies revealed enhanced cancer cell inhibition for the encapsulated drug compared to the vincristine solution. The uptake study indicated clear fluorescence for carbon dots solution and vincristine and carbon dots loaded nanoparticles upon excitation. Additionally, studies on primary mouse hepatocytes demonstrated higher fluorescence intensity in treatment groups. These results suggest that vincristine and carbon dots loaded nanoparticles are effective, target-specific carriers for liver cancer treatment. Furthermore, the carbon dots were not cytotoxic, highlighting their potential in bioimaging and cancer cell studies.

PRAME expression in fibrosarcomatous dermatofibrosarcoma protuberans.

PRAME (PReferentially expressed Antigen in MElanoma) was first identified as a malignant melanoma-specific antigen. Recently, a few cases of fibrosarcomatous dermatofibrosarcoma protuberans (FS-DFSP) were shown to have positivity for PRAME, while conventional dermatofibrosarcoma protuberans (C-DFSP) was negative. Because PRAME may be of diagnostic utility in FS-DFSP and is raising expectations as a new immunotherapy target, we examined the positivity of PRAME in FS-DFSP. Twenty-one cases of FS-DFSP and age/sex/location-matched cases of C-DFSP as a control group were examined by immunohistochemistry for CD34 and PRAME. The results were then evaluated by H-score, which was objectively and semi-quantitatively calculated using the open-source bioimaging analysis software QuPath. The results revealed that the PRAME H-score in FS-DFSP was significantly higher than that in C-DFSP (p = 0.0137). As for CD34, the H-score in FS-DFSP was significantly lower than that in C-DFSP (p < 0.001). Using these two immunohistochemical analyses in combination, the sensitivity and specificity for the diagnosis of FS-DFSP were 86% and 90%, respectively. Double staining of CD34 and PRAME revealed that PRAME-positive and CD34-positive areas did not overlap. This is the largest study to examine PRAME expression in FS-DFSP, and it confirmed the usefulness of PRAME in diagnosing this condition.

X-ray/γ-ray/Ultrasound-Activated Persistent Luminescence Phosphors for Deep Tissue Bioimaging and Therapy.

Persistent luminescence phosphors (PLPs) can remain luminescent after excitation ceases and have been widely explored in bioimaging and therapy since 2007. In bioimaging, PLPs can efficiently avoid tissue autofluorescence and light scattering interference by collecting persistent luminescence signals after the end of excitation. Outstanding signal-to-background ratios, high sensitivity, and resolution have been achieved in bioimaging with PLPs. In therapy, PLPs can continuously produce therapeutic molecules such as reactive oxygen species after removing excitation sources, which realizes sustained therapeutic activity after a single dose of light stimulation. However, most PLPs are activated by ultraviolet or visible light, which makes it difficult to reactivate the PLPs in vivo, particularly in deep tissues. In recent years, excitation sources with deep tissue penetration have been explored to activate PLPs, including X-ray, γ-ray, and ultrasound. Researchers found that various inorganic and organic PLPs can be activated by X-ray, γ-ray, and ultrasound, making these PLPs valuable in the imaging and therapy of deep-seated tumors. These X-ray/γ-ray/ultrasound-activated PLPs have not been systematically introduced in previous reviews. In this review, we summarize the recently developed inorganic and organic PLPs that can be activated by X-ray, γ-ray, and ultrasound to produce persistent luminescence. The biomedical applications of these PLPs in deep-tissue bioimaging and therapy are also discussed. This review can provide instructions for the design of PLPs with deep-tissue-renewable persistent luminescence and further promote the applications of PLPs in phototheranostics, noninvasive biosensing devices, and energy harvesting.

Phototheranostic LPP-QDs-IR-820 Nanocomposites for Specific NIR-II Imaging of Lymphatic and Photothermal Therapy of Cervical Tumors.

Precise theranostics of tumors is intricately linked to the early detection and monitoring of lymph nodes (LN) and metastases, making the targeted localization of LNs essential for tumor identification. However, designing LN-targeting probes remains a significant challenge due to issues such as lymphatic uptake, biocompatibility, and fluorescence stability. To address these challenges, near-infrared II (NIR-II) fluorescence probes are developed through meticulous analysis of LN physiological structure and passive targeting strategy for LN detection and tumor therapy. An LPP-QDs-IR-820 nanocomposite (NCs) is engineered, comprising the IR-820 molecules and ultrabright PbS@CdS quantum dots (QDs), which are encapsulated within a liposome-SH-mPEG2000 polymer matrix. These NCs demonstrates remarkable lymphatic enrichment, facilitating real-time tracking of LN via electrostatic repulsion and extracellular matrix effects. Importantly, the NCs exhibit negligible in vivo toxicity and high biocompatibility. The intense NIR-II fluorescence emissions of IR-820 and PbS@CdS QDs confer upon the NCs a high NIR-II fluorescence quantum yield (6%). The cervical tumors and their deep microvessels are clearly observed via NIR-II fluorescence imaging. Moreover, the photothermal properties of IR-820 enable the NCs to achieve a photothermal conversion efficiency of 36.56%, leading to effective photothermal therapy in cervical tumor mice.

Progressive cancer targeting by programmable aptamer-tethered nanostructures.

Scientific research in recent decades has affirmed an increase in cancer incidence as a cause of death globally. Cancer can be considered a plurality of various diseases rather than a single disease, which can be a multifaceted problem. Hence, cancer therapy techniques acquired more accelerated and urgent approvals compared to other therapeutic approaches. Radiotherapy, chemotherapy, immunotherapy, and surgery have been widely adopted as routine cancer treatment strategies to suppress disease progression and metastasis. These therapeutic approaches have lengthened the longevity of countless cancer patients. Nonetheless, some inherent limitations have restricted their application, including insignificant therapeutic efficacy, toxicity, negligible targeting, non-specific distribution, and multidrug resistance. The development of therapeutic oligomer nanoconstructs with the advantages of chemical solid-phase synthesis, programmable design, and precise adjustment is crucial for advancing smart targeted drug nanocarriers. This review focuses on the significance of the different aptamer-assembled nanoconstructs as multifunctional nucleic acid oligomeric nanoskeletons in efficient drug delivery. We discuss recent advancements in the design and utilization of aptamer-tethered nanostructures to enhance the efficacy of cancer treatment. Valuably, this comprehensive review highlights self-assembled aptamers as the exceptionally intelligent nano-biomaterials for targeted drug delivery based on their superior stability, high specificity, excellent recoverability, inherent biocompatibility, and versatile functions.

Automated early ovarian cancer detection system based on bioinformatics.

Ovarian cancer is a common gynecological tumor, with a high mortality rate and difficult clinical treatment. Early detection of ovarian cancer has significant diagnostic value. In response to the problem of poor diagnostic performance of traditional early diagnosis methods, this article designed an automated early ovarian cancer detection system to improve the detection of early ovarian cancer. The conventional early diagnosis methods include serum CA125 (carbohydrate antigen 125) detection and positron emission tomography/computed tomography (PET/CT) imaging. This article combined serum CA125 detection and PET/CT imaging to detect the CA125 level and maximum standardized uptake value (SUV) in patient's serum. When the CA125 level exceeded 35U/ml and the maximum SUV value exceeded 2.5, the test was considered positive. This article selected 200 patients from Jingzhou Hospital for the experiment and compared the three detection methods. The average specificity of single serum CA125 detection, single PET/CT imaging, and automated detection in patients under 50 were 61.24%, 79.57%, and 97.79%, respectively. The automated early ovarian cancer detection system designed in this article can significantly improve the specificity of early ovarian cancer detection and has excellent application value for early ovarian cancer detection.

A near-infrared fluorescent probe with a large Stokes shift for the detection and imaging of biothiols in vitro and in vivo.

In this study, a new near-infrared (NIR) fluorescent turn-on probe featuring a large Stokes shift (198 nm) was developed for the detection of biothiols. The probe was based on a dicyanoisophorone derivative serving as the fluorophore and a 2,4-dinitrobenzenesulfonyl (DNBS) group functioning as both a recognition site and a fluorescence quencher. In the absence of biothiols, the fluorescence of the probe was low due to the photoinduced electron transfer (PET) effect between the fluorophore and DNBS. Upon the presence of biothiols, the DNBS group underwent a nucleophilic aromatic substitution reaction with the sulfhydryl group of biothiols, leading to the release of the fluorophore and a notable emission peak at 668 nm. This developed probe exhibited exceptional selectivity and sensitivity to biothiols in solution, with an impressive detection limit of 28 nM for cysteine (Cys), 22 nM for homocysteine (Hcy), and 24 nM for glutathione (GSH). Furthermore, the probe demonstrated its applicability by successfully visualizing both endogenous and exogenous biothiols in living systems.

Intracellularly manipulable aggregation of the aggregation-induced emission luminogens.

Biophotonics has seen significant advancements with the development of optical imaging techniques facilitating the noninvasive detection of biologically relevant species. Aggregation-induced emission (AIE) materials have emerged as a novel class of luminogens exhibiting enhanced luminescence or photodynamic efficiency in the aggregated state, making them ideal for biomedical applications. The intracellularly controlled aggregation of aggregate-induced emission luminogens (AIEgens) enables high-resolution imaging of intracellular targets and diagnosis of related diseases, and enables disease therapy by exploiting the novel properties of aggregates. This review provides an in-depth analysis of the strategies employed to modulate the aggregation of AIEgens, focusing on the importance of molecular modifications to improve hydrophilicity and achieve precise control over the intercellular aggregation of AIEgens. Furthermore, the representative applications of AIEgens in bioimaging, such as enzyme activity monitoring, protein tracking, organelle function monitoring, and in vivo tumor-specific therapeutics, are reviewed. Additionally, we outline the challenges and future opportunities for AIE research, emphasizing the importance of the strategies for realizing the precisely controllable aggregation of AIEgens inside cells and the need for extending AIEgens' absorption and emission wavelengths. This review aims to elucidate the rational development of responsive AIEgens for advanced biomedical applications.

A highly effective curcumin-based fluorescent probe with single-wavelength excitation for simultaneous detection and bioimaging of Cys, Hcy and GSH.

Cysteine (Cys), homocysteine (Hcy) and glutathione (GSH) act as significant roles in many physiological processes, and their abnormal proliferation will cause multiple diseases including Alzheimer's disease, Parkinson's disease, Cardiovascular disease, atherosclerosis, and soft tissue damage. However, It is challenging work to develop a efficient method for differentiating and detecting GSH, Cys and Hcy because of their significant similarity in structures and functions. In this work, a smart fluorescent probe FBCN based on curcumin was rationally devised and developed by etherifying the phenol hydroxyl group on FBC with NBD-Cl, which emitted strong green at 516 nm. FBCN distinguished Hcy from Cys/GSH with naked eyes based on the color variation of probe solution in sunlight. Meanwhile, GSH induced the powerful fluorescence quenching of probe solution, but the fluorescence color of FBCN solution transformed from green to luminous yellow accompanied with emission wavelength redshifted from 516 nm to 540 nm or 553 nm in the existence of Hcy and Cys, respectively. Probe FBCN had outstanding sensitivity and anti-interference, low detection limit (56.5 nM, 77.7 nM, and 288 nM corresponded to Cys, Hcy, and GSH, respectively), short response time (the response time of FBCN to Cys, Hcy and GSH was 1 min, 2 min and 5 min, respectively). The DFT calculation and HRMS had verified the sensing mechanism of FBCN to biothiols. In addition, the probe was successfully utilized to detect three biothiols levels in living cell and zebrafish.

A novel ultrafast and highly sensitive NIR fluorescent probe for the detection of organophosphorus pesticides in foods and biological systems.

The threat posed by organophosphorus pesticides (OPS) to food safety, human health, and the ecological environment is significant, which underscoring the need for the development of new detection tools. We designed and synthesized a NIR fluorescent probe PT-CES which targets carboxylesterase (CES), for the detection of OPS based on the principle of enzyme inhibition. The PT-CES is capable of instantaneous response to CES, exhibiting excellent stability, anti-interference capability. PT-CES realizes the quantitative detection of CES and OPS. It is noteworthy that PT-CES shows excellent stable and accurate detection ability in vegetable pesticide testing. It also enables the monitoring of CES activity in cells and liver tissue. This provides a novel tool for tracking the effect of OPS on CES activity in biological systems. Furthermore, it provides a useful method for ensuring food safety and enhancing pesticide residue analysis.