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The efficient extraction of various analytes from a wide spectrum of matrices with organic solvents is still a great challenge in analytical chemistry. Especially polar and charged compounds are hard to extract in combination with neutral analytes of intermediate to low polarity. The QuEChERS method is often chosen and has been adapted not only to the analysis of food samples, but also to environmental matrices (soil, wastewater) or biota. In this study, we overcome major drawbacks of QuEChERS such as low recoveries of charged analytes and impairment of downstream analysis by high salt loads. The new extraction method, applicable to liquid and solid samples, is called SWIEET (sugar water isopropanol ethyl nitrile extraction technique). Phase separation of the otherwise miscible extraction solvents water and acetonitrile is achieved by sugaring-out instead of salting-out. Extraction efficiencies were greatly improved by adding isopropanol to the acetonitrile phase. The concentrations of the additives glucose and isopropanol, as well as temperature, were optimized by a design of experiment. Further improvement was achieved through electro- or double-extractions. For all sample types tested (surface water, wastewater treatment plant effluent, tomato, soil, and oats), recoveries and precision were higher with SWIEET than with the established QuEChERS method. From wastewater treatment plant effluent, 75% recovery on average were achieved with our SWIEET method compared to 37% with QuEChERS for a model analyte mixture with polarities of logDpH7 = - 5.7 - 3.5. Higher recoveries and lower standard deviations compared to QuEChERS were achieved especially for polar and charged analytes such as metformin. Handling proved to be easy, since there was no additional solid phase and no tedious weighing of salts.

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BACKGROUND: ML predictive models have shown their capability to improve risk prediction and assist medical decision-making, nevertheless, there is a lack of accuracy systems to early identify future rapid CKD progressors in Colombia and even in South America. OBJECTIVE: The purpose of this study was to develop a series of interpretable machine learning models that predict GFR at 6-months, 9-months, and 12-months. STUDY DESIGN AND SETTING: Over 29,000 CKD patients stages 1 to 3b (estimated GFR, <60 ml/min / 1.73 m2) with an average of 3-year follow-up data were included. We used the machine learning extreme gradient boosting (XGBoost) to build three models to predict the next eGFR. Models were internally and externally validated. In addition, we included SHapley Additive exPlanation (SHAP) values to offer interpretable global and local prediction models. RESULTS: All models showed a good performance in development and external validation. However, the 6-months XGBoost prediction model showed the best performance in internal (MAE average= 6.07; RSME= 78.87), and in external validation (MAE average= 6.45, RSME= 18.94). The top 3 most influential features that pushed the predicted eGFR value to lower values were the interpolated values for eGFR and creatinine, and eGFR at baseline. CONCLUSION: In the current study we have developed and validated machine learning models to predict the next eGFR value at different intervals. Furthermore, we attempted to approach the need for prediction explanation by offering transparent predictions.

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Rheumatoid arthritis (RA) is a chronic, systemic, autoimmune condition that primarily affects the joints and periarticular soft tissues. In the past two decades, the discovery of new biomarkers has contributed to advances in the understanding of the pathogenesis and natural history of RA. These biomarkers, including genetic, clinical, serological and imaging biomarkers, play a key role in the different stages and aspects of RA, from the so called "pre-clinical RA", which is characterized by subclinical pathological events, such as autoimmunity and inflammation, to diagnosis (including differential diagnosis), treatment decision making and disease monitoring. This review will provide an overview on the current role of traditional and newer biomarkers in the main aspects of RA management, from the identification of individuals 'at-risk' of RA who are likely to progress to clinically evident disease, to 'early' diagnosis of RA, prognosis, precision medicine, and prediction of response to treatment.

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INTRODUCTION: Laboratories use their performance in external quality assurance (EQA) to establish quality planning strategies and to assess whether testing processes require improvement. METHODS: The EQA performance of the hematology and coagulation test parameters on the Royal College of Pathologists of Australasia EQA program was evaluated over a 4-year cycle at an academic hospital in Johannesburg, South Africa. The test performance was determined from analytical quality specification (APS) and/or z-scores. Bias and imprecision were used to calculate sigma (σ) metric scores. Specifications from European Federation of Laboratory Medicine and/or biological variation were applied. RESULTS: The laboratory achieved a mean testing score of 98.7 ± 4.0%. There were 103 (10.7%) unacceptable results. On investigation, root causes included: presurvey issues (83%), transcription errors (9%), random errors (6%), and test performance errors (3%). All test parameters evaluated achieved an acceptable median APS during the study period. The mean z-scores, however, were >2 and unacceptable for mean cell hemoglobin concentration and hematocrit. On investigation, this was attributed to significant delay in transport and storage of full blood count samples. White cell count and d-dimer achieved a σ ≥ 6. CONCLUSION: EQA participation assisted the laboratory in maintaining a quality system. Close monitoring is necessary for international laboratories to avoid sample delays that can affect result quality.

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The current paper reports two new, robust, and efficient conditions for electromembrane extraction of acidic substances from human plasma. Two systems were developed based on eutectic solvents: A1 ("A" for acid) comprised dodecyl methyl sulfoxide and thymol in 1:2 ratio (w/w) as liquid membrane, while A2 used [6-methylcoumarin:thymol (1:2)]:2-nitrophenyl octyl ether in 2:1 ratio (w/w). The performance of A1 and A2 was characterized by extraction of 31 acidic model analytes (pharmaceutical drugs and nutrients) spiked into 100 µL human plasma diluted 1:1 (v/v) with phosphate buffer pH 7.4. The acceptor solution was 50 mM NH4HCO3 buffer pH 10.0, and extraction was performed at an agitation rate of 750 RPM. Voltage and extraction time were 30 V for 30 min and 10 V for 20 min for A1 and A2, respectively. Under optimal conditions, A1 extracted analytes with 1.8 ≤ log P ≤ 6.0 with an average recovery (R) of 85.1%, while A2 extracted in a range of 0.5 ≤ log P ≤ 6.0 with an average recovery of 79.9%. Meanwhile, extraction current was low at 9 and 26 µA, respectively, which is indicative of good system robustness. Using UHPLC-MS/MS analysis of the acceptor solution, repeatability of the A1 and A2 methods was determined to be 2.8-7.7% and 3.3-9.4% for R > 40%, matrix effects were 82-117% and 84-112%, respectively, and linear calibration curves were obtained. The performance and compatibility with human plasma represent a major improvement over previous state-of-the-art liquid membranes for acidic analytes, namely 1-octanol.

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Electrochemical sensors and electroanalytical techniques become emerging as effective and low-cost tools for rapid assessment of special parameters of the food quality. Chemically modified electrodes are developed to change properties and behaviour, particularly sensitivity and selectivity, of conventional electroanalytical sensors. Within this comprehensive review, novel trends in chemical modifiers material structure, electrodes construction and flow analysis platforms are described and evaluated. Numerous recent application examples for the detection of food specific analytes are presented in a form of table to stimulate further development in both, the basic research and commercial field.

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Background The escalating prevalence of diabetes underscores the need for precise diagnostic tools to facilitate effective management. Hemoglobin A1c (HbA1c) is a crucial biomarker for long-term glycemic control in diabetic patients. Point-of-care testing (POCT) for HbA1c offers rapid, accessible alternatives to conventional laboratory methods, but uncertainties persist regarding the accuracy and reliability of POCT assays. Methods This study evaluates the analytical performance of two boronate-affinity based HbA1c POCT assays, the GreenCare A1c and Cera-Stat HbA1c. Various analytical parameters including precision, linearity, comparison, accuracy are assessed following guidelines from Clinical and Laboratory Standards Institute (CLSI), with results applied to certification criteria from the National Glycohemoglobin Standardization Program (NGSP) and International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). Furthermore, 52 and 13 frozen EDTA whole blood samples were respectively used for additional evaluation of accuracy and interference due to Hb variants for the GreenCare A1c assay. Results Both GreenCare and Cera-Stat demonstrated good precision (repeatability CV% 1.5-1.9 and total imprecision CV% 1.6-2.2), linearity (R2= 0.9996 & 0.9990), and correlation (r= 0.982 & 0.978) with an established HbA1c analyzer, the Bio-Rad D100. The GreenCare also exhibited good accuracy with frozen EDTA samples with known HbA1c values. Both assays met the certification criteria from NGSP and IFCC, classifying them as 'standard' according to IFCC model for quality targets for HbA1c. Conclusion This evaluation affirms the reliability of GreenCare and Cera-Stat POCT assays for HbA1c measurements, which can potentially reduce unnecessary referrals and enhance the overall quality of diabetes diagnosis and treatment.

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The detection of small molecules beyond glucose remains an ongoing challenge in the field of biomolecular sensing owing to their small size, diverse structures, and lack of alternative non-enzymatic sensing methods. Here, we present a new reagentless electrochemical approach for small molecule detection that involves directed movement of electroactive analytes through a self-assembled monolayer to an electrode surface. Using this method, we demonstrate detection of several physiologically relevant small molecules as well as the capacity for the system to operate in several biological fluids. We anticipate that this mechanism will further improve our capacity for small molecule measurement and provide a new generalizable monolayer-based technique for electrochemical assessment of various electroactive analytes.

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OBJECTIVES: Bariatric surgery is a well-established treatment for obesity and type 2 diabetes. Tirzepatide, a dual GIP/GLP-1 receptor agonist, has emerged as a promising therapy for type 2 diabetes. This study aimed to compare the effects of bariatric surgery, semaglutide (a GLP-1 receptor agonist), and tirzepatide in Sprague-Dawley rats fed a high-fat diet. METHODS: Rats were divided into surgery, semaglutide, and tirzepatide treatment groups, along with a control group (sham). Weight, oral glucose tolerance, and levels of metabolic markers were assessed, along with adipose and liver tissue analysis. RESULTS: Surgery led to a 15.5% weight reduction, while rats treated with semaglutide exhibited a 10.7% reduction. Tirzepatide treatment at various concentrations (10, 50, and 100 nmol/kg) resulted in weight reductions of 5.0%, 14.9%, and 17.7%, respectively, compared to the sham group. Metabolic analyte levels decreased in intervention groups compared to the sham group, indicating improved metabolic health and glucose tolerance. Adipose tissue weight and hepatic liver fat droplets decreased in the intervention groups. CONCLUSION: Bariatric surgery and tirzepatide treatment significantly improved metabolic parameters in obese rats. Tirzepatide, particularly at higher concentrations, showed pronounced improvements compared to surgery and semaglutide. These findings suggest that high doses of tirzepatide could be explored as an alternative to bariatric surgery for the treatment of obesity.

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The widespread adoption of small-molecule fluorescence detection methodologies in scientific research and industrial contexts can be ascribed to their inherent merits, including elevated sensitivity, exceptional selectivity, real-time detection capabilities, and non-destructive characteristics. In recent years, there has been a growing focus on small-molecule fluorescent probes engineered with sulfur elements, aiming to detect a diverse array of biologically active species. This review presents a comprehensive survey of sulfur-based fluorescent probes published from 2017 to 2023. The diverse repertoire of recognition sites, including but not limited to N, N-dimethylthiocarbamyl, disulfides, thioether, sulfonyls and sulfoxides, thiourea, thioester, thioacetal and thioketal, sulfhydryl, phenothiazine, thioamide, and others, inherent in these sulfur-based probes markedly amplifies their capacity for detecting a broad spectrum of analytes, such as metal ions, reactive oxygen species, reactive sulfur species, reactive nitrogen species, proteins, and beyond. Owing to the individual disparities in the molecular structures of the probes, analogous recognition units may be employed to discern diverse substrates. Subsequent to this classification, the review provides a concise summary and introduction to the design and biological applications of these probe molecules. Lastly, drawing upon a synthesis of published works, the review engages in a discussion regarding the merits and drawbacks of these fluorescent probes, offering guidance for future endeavors.

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Despite immense importance of reference intervals (RIs) for clinical diagnosis, there have been no reliable RIs available for Nepalese. Hence, this nationwide study was organized to establish RIs for 30 common biochemical parameters. This study was conducted following the harmonized protocol provided by IFCC Committee on Reference Interval and Decision Limits (C-RIDL) with recruitment of 617 apparently healthy volunteers (18 - 65 years) by near-equal gender balance from 5 major cities. Fasting blood were collected, serum was separated and measured collectively using Beckman-Coulter/Olympus AU480 chemistry analyzer. The sources of variations of reference values (RVs) were evaluated by multiple regression analysis and nested ANOVA. Latent abnormal values exclusion (LAVE) method was applied to reduce influence of latent diseases. RIs were standardized based on a value-assigned serum panel provided by C-RIDL. By ANOVA, no between-city differences were observed, while sex-related changes were typically noted for urate, creatinine, iron, γ-glutamyl transferase (GGT), immunoglobulin M, and transferrin, but not for high-density lipoprotein cholesterol. Age-related changes were observed for total cholesterol (TC), triglyceride, low-density lipoprotein cholesterol, and C-reactive protein (CRP). RIs were successfully derived all parametrically. The LAVE procedure was effective in lowering upper limits for aspartate aminotransferase, alanine aminotransferase (ALT), and CRP. Compared to other collaborating countries, Nepalese RIs were low for urea, cholesterols, ALT, and high for triglyceride, GGT, CRP, immunoglobulin G, and complements. The RIs for major chemistry analytes were derived and standardized for nationwide use in Nepal. This study distinctly elucidated sources of variation and international features of Nepalese RIs. Supplementary Information: The online version supplementary material available at 10.1007/s12291-023-01123-6.

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Self-powered biosensors are innovative devices that can detect and analyze biological or chemical substances without the need for an external power source. These biosensors can convert energy from the surrounding environment or the analyte itself into electrical signals for sensing and data transmission. The self-powered nature of these biosensors offers several advantages, such as portability, autonomy, and reduced waste generation from disposable batteries. They find applications in various fields, including healthcare, environmental monitoring, food safety, and wearable devices. While self-powered biosensors are a promising technology, there are still challenges to address, such as improving energy efficiency, sensitivity, and stability to make them more practical and widely adopted. This review article focuses on exploring the evolving trends in self-powered biosensor design, outlining potential advantages and limitations. With a focal point on enzymatic biofuel cell power generation, this article describes various sensing mechanisms that employ the analyte as substrate or fuel for the biocatalyst's ability to generate current. Technical aspects of biofuel cells are also examined. Research and development in the field of self-powered biosensors is ongoing, and this review describes promising areas for further exploration within the field, identifying underexplored areas that could benefit from further investigation.

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Fluorescent chemosensors have become vital tools for detecting toxic ions due to their exceptional sensitivity, selectivity, and rapid response times. These sensors function through various mechanisms, each providing unique advantages for specific applications. This review offers a comprehensive overview of the mechanistic innovations in fluorescent chemosensors, emphasizing five key approaches: Photoinduced Electron Transfer (PET), Fluorescence Resonance Energy Transfer (FRET), Intramolecular Charge Transfer (ICT), Aggregation-Induced Emission (AIE), and Excited-State Intramolecular Proton Transfer (ESIPT). We highlight the substantial progress made in developing these chemosensors, discussing their design principles, sensing mechanisms, and practical applications, with a particular focus on their use in detecting toxic ions relevant to environmental and biological contexts.

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We recently reported the potential application of recombinant prothrombin activator ecarin (RAPClot™) in blood diagnostics. In a new study, we describe RAPClot™ as an additive to develop a novel blood collection prototype tube that produces the highest quality serum for accurate biochemical analyte determination. The drying process of the RAPClot™ tube generated minimal effect on the enzymatic activity of the prothrombin activator. According to the bioassays of thrombin activity and plasma clotting, γ-radiation (>25 kGy) resulted in a 30-40% loss of the enzymatic activity of the RAPClot™ tubes. However, a visual blood clotting assay revealed that the γ-radiation-sterilized RAPClot™ tubes showed a high capacity for clotting high-dose heparinized blood (8 U/mL) within 5 min. This was confirmed using Thrombelastography (TEG), indicating full clotting efficiency under anticoagulant conditions. The storage of the RAPClot™ tubes at room temperature (RT) for greater than 12 months resulted in the retention of efficient and effective clotting activity for heparinized blood in 342 s. Furthermore, the enzymatic activity of the RAPClot™ tubes sterilized with an electron-beam (EB) was significantly greater than that with γ-radiation. The EB-sterilized RAPClot™ tubes stored at RT for 251 days retained over 70% enzyme activity and clotted the heparinized blood in 340 s after 682 days. Preliminary clinical studies revealed in the two trials that 5 common analytes (K, Glu, lactate dehydrogenase (LD), Fe, and Phos) or 33 analytes determined in the second study in the γ-sterilized RAPClot™ tubes were similar to those in commercial tubes. In conclusion, the findings indicate that the novel RAPClot™ blood collection prototype tube has a significant advantage over current serum or lithium heparin plasma tubes for routine use in measuring biochemical analytes, confirming a promising application of RAPClot™ in clinical medicine.

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To date, the most commonly used column characterization databases do not determine the relative positive charge associated with new generation RP columns, or they fail to successfully discriminate between RP columns of purportedly low level positive and neutral characters. This paper rectifies this in that it describes a convenient and robust chromatographic procedure for the assessment of the low levels of positive charge on a range of RP columns. The low degree of positive charge was determined by their electrostatic attraction towards the negatively charged 4-n-octylbenzene sulfonic acid (4-OBSA) relative to their retention of the hydrophobic marker toluene (Tol). The new parameter (α4-OBSA/Tol) was determined for 15 commercially available RP-LC columns. When this was combined with existing Tanaka parameters it was possible to guide the chromatographer towards similar columns as "backup / equivalent phases" or dissimilar columns for exploitation in method development strategies. It should be noted that under certain chromatographic conditions the retention mechanism(s) may be too complex to allow direct location of a "backup / equivalent" column(s). The α4-OBSA/Tol results indicate that even the new generation neutral alkyl phases may exhibit a small degree of positive charge at low buffer concentrations. Mobile phases containing low % MeCN were demonstrated to promote mixed mode (anionic exchange / hydrophobic) retention whereas at high % MeCN anionic exchange retention dominated. The measure of electrostatic repulsion between positively charged columns and positively charged bases was assessed by evaluating the relative retention of a range of bases and neutral analytes. The greatest electrostatic repulsion was observed with hydrophilic bases. While there was no correlation between the positive charge associated with the phases assessed by electrostatic attraction or repulsion, the columns could be broadly divided into three subsets (i.e., significant positive character, medium to low positive character and insignificant positive character). Finally, the results were used to highlight the usefulness of the column characterization database containing the new anionic exchange retention parameter (α4-OBSA/Tol) for the selection of an equivalent column possessing a low level of positive character in the analysis of a real-life biopharmaceutical application.

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Progress has been made studying cell-cell signaling communication processes. However, due to limitations of current sensors on time and spatial resolution, the role of many extracellular analytes is still unknown. A single walled carbon nanotube (SWNT) platform was previously developed based on the avidin-biotin immobilization of SWNT to a glass substrate. The SWNT platform provides real time feedback about analyte concentration and has a high concentration of evenly distributed sensors, both of which are essential for the study of extracellular analytes. Unfortunately, this initial SWNT platform is synthesized through unsterile conditions and cannot be sterilized post-production due to the delicate nature of the sensors, making it unsuitable for in vitro work. Herein the multiple-step process for SWNT immobilization is modified and the platform's biocompatibility is assessed in terms of sterility, cytotoxicity, cell proliferation, and cell morphology through comparison with non-sensors controls. The results demonstrate the SWNT platform's sterility and lack of toxicity over 72 h. The proliferation rate and morphology profiles for cells growing on the SWNT platform are similar to those grown on tissue culture substrates. This novel nano-sensor platform preserves cell health and cell functionality over time, offering opportunities to study extracellular analytes gradients in cellular communication.

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In this study, water was used as an additive in the methanol-modified carbon dioxide-based eluent for the elution of some basic organic compounds from a hybrid silica column via supercritical fluid chromatography (SFC). The experiments were applied to sulfonamides, propranolol, and other organic nitrogen compounds involving aromatic rings from different classes of amine, pyrimidine, and purine with different pKa values (the pKa values for the studied analytes range from 4.6 to 10.4). The results revealed different responses to the different percentages of water addition. Adding 1~2% of water to the modifier (methanol) led to a positive effect manifested by more symmetrical peak shapes and reduced retention times for most compounds. The key factor for this improvement in the properties of chromatographic peaks is due to the adsorption of water on the silanol groups of the stationary phase, consequently resembling the phenomena observed in hydrophilic interaction liquid chromatography (HILIC). Moreover, the availability of hydrogen bond acceptor and donor sites in the analyte structure is an important factor to be considered when adding water as an additive to the modifier for improving the chromatographic peaks. However, introducing water in an amount higher than 3% resulted in perturbed chromatographic signals. It was also found that water as an additive alone could not successfully elute propranolol from the hybrid silica column with an acceptable peak shape; thus, the addition of a strong base such as amine salts was also necessary. The proposed use of a particular amount of water in the mobile phase could have a positive effect compared to the same mobile phase without water, improving the chromatographic peak properties of the elution of some basic organic compounds from the hybrid silica column.

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This study demonstrates the capability of Raman microscopy for detecting structural differences in Giardia cells exposed to different drugs and incubation times. While metronidazole (MTZ) visibly affects the cells by inducing extracellular vesicle releases of toxic iron intermediates and modified triple-bond moieties, oseltamivir (OSM) alters the phenylalanine and lipid structures. Modifications in the heme protein environment and the transformation of iron from ferric to ferrous observed for both drug treatments are more notable for MTZ. Different contents and amounts of vesicle excretion are detected for 24 h or 48 h with MTZ incubation. At a shorter drug exposure, releases of altered proteins, glycogen, and phospholipids dominate. Agglomerates of transformed iron complexes from heme proteins and multiple-bond moieties prevail at 48 h of treatment. No such vesicle releases are present in the case of OSM usage. Drug incorporations into the cells and their impact on the plasma membrane and the dynamics of lipid raft confirmed by confocal fluorescence microscopy reveal a more destructive extent by OSM, corroborating the Raman results. Raman microscopy provides a broader understanding of the multifaceted factors and mechanisms responsible for giardiasis treatment or drug resistance by enabling a label-free, simultaneous monitoring of structural changes at the cellular and molecular levels.

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The two-step preconcentration technique consisting of large-volume sample stacking (LVSS) and micelle to solvent stacking (MSS) in cyclodextrin-modified electrokinetic chromatography (CDEKC) was developed for the analysis of five cationic alkaloids in complex Chinese herbal prescriptions. Relevant parameters affecting separation and stacking performance were optimized separately. Under the optimal LVSS-MSS-CDEKC conditions, less analysis time and organic solvent were required, and the enhancement factors of analytes ranged from 12 to 15 compared with the normal CDEKC separation mode. Further, all validation results demonstrated good applicability and multiple alkaloids (epiberberine, dehydrocorydaline, jatrorrhizine, coptisine and berberine) in Yangxinshi tablet (YXST) have been simultaneously determined. This approach presents powerful potential for the determination of multiple components in complex preparations of Chinese medicine.

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Porphyrins and porphyrin derivatives have been intensively explored for a number of applications such as sensing, catalysis, adsorption, and photocatalysis due to their outstanding photophysical properties. Their usage in sensing applications, however, is limited by intrinsic defects such as physiological instability and self-quenching. To reduce self-quenching susceptibility, researchers have developed porphyrin metal-organic frameworks (MOFs). Metal-organic frameworks (MOFs), a unique type of hybrid porous coordination polymers comprised of metal ions linked by organic linkers, are gaining popularity. Porphyrin molecules can be integrated into MOFs or employed as organic linkers in the production of MOFs. Porphyrin-based MOFs are a separate branch of the huge MOF family that combines the distinguishing qualities of porphyrins (e.g., fluorescent nature) and MOFs (e.g., high surface area, high porosity) to enable sensing applications with higher sensitivity, specificity, and extended target range. The key synthesis techniques for porphyrin-based MOFs, such as porphyrin@MOFs, porphyrinic MOFs, and composite porphyrinic MOFs, are outlined in this review article. This review article focuses on current advances and breakthroughs in the field of porphyrin-based MOFs for detecting a variety of targets (for example, metal ions, anions, explosives, biomolecules, pH, and toxins). Finally, the issues and potential future uses of this class of emerging materials for sensing applications are reviewed.