Identification of Treg-related prognostic molecular subtypes and individualized characteristics in clear cell renal cell carcinoma through single-cell transcriptomes and bulk RNA sequencing.

BACKGROUND: In clear cell renal cell carcinoma (ccRCC), the role of Regulatory T cells (Treg cells) as prognostic and immunotherapy response predictors is not fully explored. METHODS: Analyzing renal clear cell carcinoma datasets from TISCH, TCGA, and GEO, we focused on 8 prognostic Treg genes to study patient subtypes in ccRCC. We assessed Treg subtypes in relation to patient prognosis, tumor microenvironment, metabolism. Using Cox regression and principal component analysis, we devised Treg scores for individual patient characterization and explored the molecular role of C1QL1, a critical gene in the Treg model, through in vivo and in vitro studies. RESULTS: Eight Treg-associated prognostic genes were identified, classifying ccRCC patients into cluster A and B. Cluster A patients showed poorer prognosis with distinct clinical and molecular profiles, potentially benefiting more from immunotherapy. Low Treg scores correlated with worse outcomes and clinical progression. Low scores also suggested that patients might respond better to immunotherapy and targeted therapies. In ccRCC, C1QL1 knockdown reduced tumor proliferation and invasion via NF-kb-EMT pathways and decreased Treg cell infiltration, enhancing immune efficacy. CONCLUSIONS: The molecular subtype and Treg score in ccRCC, based on Treg cell marker genes, are crucial in personalizing ccRCC treatment and underscore C1QL1's potential as a tumor biomarker and target for immunotherapy.

A Novel and Rapid Smear Cytomorphology Detection Strategy Based on Upconversion Nanoparticles Immunolabeling Integrated with Wright's Staining for Accurate Diagnosis of Leukemia.

Background: Accurate, sensitive, and rapid identification of leukemia cells in blood and bone marrow is of paramount significance for clinical diagnosis. An integrative technique combining traditional cytomorphology with immunophenotyping was proposed to improve the diagnostic efficiency in leukemia. On account of high photostability, biocompatibility, and signal-to-background ratio, upconversion nanoparticles (UCNPs) as luminescent labels have drawn substantial research scrutiny in immunolabeling. Methods: To achieve simultaneous determination, NaYF4:Yb,Er UCNPs were coupled with CD38 antibodies to construct immunofluorescence probes that were developed to bind to diffuse large B cell lymphoma (DLBCL) cells, followed by Wright's staining that has been widely used in clinical work for morphological diagnosis. Further, the experimental conditions were optimized, such as medium, slice-making method, antibody dosage, incubation time, etc. Results: The cell morphology and immunolabeling could be observed simultaneously, and its simple operation rendered it a possibility for clinical diagnosis. The developed immunolabeling assay could achieve DLBCL cell counting with high reproducibility and stability, and the detection limit was as low as 1.54 cell/slice (>3 σ/s). Moreover, the proposed method also realized real blood and bone marrow sample analysis, and the results were consistent with the clinical diagnosis. Conclusion: Overall, this strategy can be carried out after simple laboratory training and has prospective biomedical applications in leukemia classification, diagnosis validation, and differential diagnostics.

Identification and prediction of immune checkpoint inhibitors-related pneumonitis by machine learning.

Background: Immune checkpoint inhibitor (ICI)-related pneumonitis (IRP) is a common and potentially fatal clinical adverse event. The identification and prediction of the risk of ICI-related IRP is a major clinical issue. The objective of this study was to apply a machine learning method to explore risk factors and establish a prediction model. Methods: We retrospectively analyzed 48 patients with IRP (IRP group) and 142 patients without IRP (control group) who were treated with ICIs. An Elastic Net model was constructed using a repeated k-fold cross-validation framework (repeat = 10; k = 3). The prediction models were validated internally and the final prediction model was built on the entire training set using hyperparameters with the best interval validation performance. The generalizability of the final prediction model was assessed by applying it to an independent test set. The overall performance, discrimination, and calibration of the prediction model were evaluated. Results: Eleven predictors were included in the final predictive model: sindillizumab, number of ≥2 underlying diseases, history of lung diseases, tirelizumab, non-small cell lung cancer (NSCLC), percentage of CD4+ lymphocytes, body temperature, KPS score ≤70, hemoglobin, cancer stage IV, and history of antitumor therapy. The external validation of the risk prediction model on an independent test set of 37 patients and showed good discrimination and acceptable calibration ability: with AUC of 0.81 (95% CI 0.58-0.90), AP of 0.76, scaled Brier score of 0.31, and Spiegelhalter-z of -0.29 (P-value:0.77). We also designed an online IRP risk calculator for use in clinical practice. Conclusion: The prediction model of ICI-related IRP provides a tool for accurately predicting the occurrence of IRP in patients with cancer who received ICIs.

On-line monitoring of a recirculating-flow fluorescent capillary system for exploring the interaction mechanism of carbon dots/metal ions.

The interaction mechanism between carbon dots (CDs) and metal ions is essential for optimizing their design, synthesis, and application. However, it must be accurately distinguished and quantified because of CDs' complex structure, composition, and coexisting various response mechanisms or products. Herein, a recirculating-flow fluorescence capillary analysis (RF-FCA) system was developed to online monitor the fluorescence kinetics of CDs interacting with metal ions. The fluorescence kinetics of purification and dissociation of CDs/metal ion complexes were easy to monitor online by integrating immobilized CDs and RF-FCA. Here, CDs derived from citric acid and ethylenediamine were used as a model system. We found that the fluorescence of CDs is quenched by Cu(II) and Hg(II) only through the formation of a coordination complex, by Cr(VI) only through the inner filtering effect, and by Fe(III) through the above two mechanisms. Then the kinetics of the competitive interaction between metal ions were used to address the difference of binding sites on CDs with metal ions, wherein Hg(II) was bound to other sites of CDs besides the same sites of CDs with Fe(III) and Cu(II). Finally, from the fluorescence kinetics of fluorescent molecules in the CD structure with metal ions, the difference was due to the presence of two fluorescent centers in the carbon core and molecular state in the CDs. Therefore, the RF-FCA system can distinguish and quantify the interaction mechanism between metal ions and CDs effectively and accurately and be a potential detection or performance characterization method.

Primary hepatic lymphoma of MALT type mimicking hepatic adenoma treated by hepatectomy: a case report and literature review.

Background: Primary hepatic lymphoma (PHL) is a rare malignant tumor. Extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT) is an indolent lymphoma occurring at extranodal sites. The stomach is the most common organ affected by MALT lymphoma, whereas liver-related lymphoma is rarely reported. Its atypical clinical presentation often delays the diagnosis. Owing to the rarity of PHL, identifying its optimal treatment still remains a challenge. Herein, we report a case of PHL of the MALT type mimicking hepatic adenoma that was treated by hepatectomy without chemotherapy and review the scarce literature. Our findings suggest that surgery is an alternative approach to cure patients with localized hepatic lymphoma. Case summary: A 55-year-old woman was admitted to our hospital because of upper abdominal discomfort, and a liver lesion was detected by computed tomography. She did not have nausea, fever, fatigue, jaundice, weakness, night sweats, or weight loss before admission. And her previous medical history was unremarkable. There were no positive signs on physical examination. Based on her preoperative examination including magnetic resonance imaging, the liver lesion was suspected to be a hepatic adenoma; however, the possibility of it being a malignancy like hepatocellular carcinoma was not excluded. Therefore, a decision of resection of the lesion was made. During the operation, hepatectomy of segment 4b and cholecystectomy were performed. The patient recovered well; however, after postoperative pathological examination, the lesion was diagnosed as a hepatic lymphoma of MALT type. The patient was reluctant to undergo chemotherapy or radiotherapy. At 18-month follow-up, no significant recurrence was observed, indicating that the treatment had a curative effect. Conclusion: Notably, primary hepatic lymphoma of MALT type is a rare, low-grade B-cell malignancy. Making an accurate preoperative diagnosis of this disease is usually difficult, and liver biopsy is an appropriate avenue to improve the diagnostic accuracy. In patients with a localized tumor lesion, hepatectomy followed by chemotherapy or radiotherapy should be considered to achieve better outcomes. Although this study describes an unusual type of hepatic lymphoma mimicking a benign tumor, it has its inherent limitations. More clinical studies are required to establish guidelines for the diagnosis and treatment of this rare disease.

Characterization and Immunogenicity of Recombinant A. flavus Uox Modified by Co/EDTA Carbon Dots.

BACKGROUND: Uricase (Uox) is a major drug in gout and a supplementary drug in cancer treatment. Because allergic reactions caused by Uox limit its clinical application,10% Co/EDTA was used to chemically modify Uox from A. flavus to reduce its immunogenicity. METHODS: The immunogenicity of Uox and 10% Co/EDTA-Uox was examined by determining the antibody titer and concentration of IL-2, IL-6, IL-10, and TNF-ß in quail and rat serum. Moreover, we examined the pharmacokinetics of 10% Co/EDTA-Uox in rats and acute toxicity in mice. RESULTS: The concentration of UA decreased from 771.85 ±180.99 to 299.47 ±20.37 µmoL/L（p<0.01） in the hyperuricemia model of quails injected by 10% Co/EDTA-Uox. Two-way immuno-diffusion electrophoresis revealed that 10% Co/EDTA-Uox did not produce antibody, whereas the antibody titer against Uox was 1:16. The concentrations of four cytokines in the 10% Co/EDTA-Uox group were significantly lower than in Uox group (p < 0.01)； The titer of IgG and IgM against 10% Co/EDTA-Uox was significantly lower than that against Uox at different serum dilutions (p < 0.0001). The pharmacokinetic data indicated that the half-life time of 10% Co/EDTA- Uox( 69.315h) was significantly longer than that of Uox(13.4 h)（p<0.01）. The tissue section of the liver, heart, kidney, and spleen revealed no toxicity in Uox and 10% Co/EDTA- Uox groups. CONCLUSION: 10% Co/EDTA-Uox possesses little immunogenicity, a long half-life time, and a highly efficient degradation of UA.

A new spectrophotometric method for uric acid detection based on copper doped mimic peroxidase.

Cascade reactions catalyzed by natural uricase and mimic peroxidase (MPOD) have been applied for uric acid (UA) detection. However, the optimal catalytic activity of MPOD is mostly in acidic conditions (pH 2-5), mismatching the optimal catalytic alkaline environment of uricase. In this paper, using CuSO4 and urea as raw materials, a MPOD with high catalytic activity in alkaline environment was synthesized by hydrothermal method. Then, based on coupling reaction of uricase/UA/MPOD/guaiacol (GA) system, a novel spectrophotometric method was established to detect 5-60 µmol/L UA (limit of detection = 3.14 µmol/L (S/N = 3)) and accurately quantified serum UA (275.6 ± 39.9 µmol/L, n = 5) with 95-105% of standard addition recovery. The results were consistent with commercial UA kit (p > 0.05). The MPOD could replace natural POD to reduce the cost of UA detection due to simple preparation and cheap raw materials, and is expected to achieve the specific detection of some substances, like glucose and cholesterol, combined with glucose oxidase and cholesterol oxidase.

Data analysis guidelines for single-cell RNA-seq in biomedical studies and clinical applications.

The application of single-cell RNA sequencing (scRNA-seq) in biomedical research has advanced our understanding of the pathogenesis of disease and provided valuable insights into new diagnostic and therapeutic strategies. With the expansion of capacity for high-throughput scRNA-seq, including clinical samples, the analysis of these huge volumes of data has become a daunting prospect for researchers entering this field. Here, we review the workflow for typical scRNA-seq data analysis, covering raw data processing and quality control, basic data analysis applicable for almost all scRNA-seq data sets, and advanced data analysis that should be tailored to specific scientific questions. While summarizing the current methods for each analysis step, we also provide an online repository of software and wrapped-up scripts to support the implementation. Recommendations and caveats are pointed out for some specific analysis tasks and approaches. We hope this resource will be helpful to researchers engaging with scRNA-seq, in particular for emerging clinical applications.

Analgesic Effects of Repetitive Transcranial Magnetic Stimulation in Patients With Advanced Non-Small-Cell Lung Cancer: A Randomized, Sham-Controlled, Pilot Study.

Objective: Current pharmacological intervention for the cancer-related pain is still limited. The aim of this study was to explore whether repetitive transcranial magnetic stimulation (rTMS) could be an effective adjuvant therapy to reduce pain in patients with advanced non-small cell lung cancer (NSCLC). Methods: This was a randomized, sham-controlled study. A total of 41 advanced NSCLC patients with uncontrolled pain (score≥4 on pain intensity assessed with an 11-point numeric rating scale) were randomized to receive active (10 Hz, 2000 stimuli) (n = 20) or sham rTMS (n = 20) for 3 weeks. Pain was the primary outcome and was assessed with the Numeric Rating Scale (NRS). Secondary outcomes were oral morphine equivalent (OME) daily dose, quality of life (WHO Quality of Life-BREF), and psychological distress (the Hospital Depression and Anxiety Scale). All outcomes were measured at baseline, 3 days, 1 week, 2 weeks, and 3 weeks. Results: The pain intensity in both groups decreased gradually from day 3 and decreased to the lowest at the week 3, with a decrease rate of 41.09% in the rTMS group and 23.23% in the sham group. The NRS score of the rTMS group was significantly lower than that of the sham group on the week 2 (p < 0.001, Cohen's d =1.135) and week 3 (p=0.017, Cohen's d = -0.822). The OME daily dose, physiology and psychology domains of WHOQOL-BREF scores, as well as the HAM-A and HAM-D scores all were significantly improved at week 3 in rTMS group. Conclusion: Advanced NSCL patients with cancer pain treated with rTMS showed better greater pain relief, lower dosage of opioid, and better mood states and quality of life. rTMS is expected to be a new effective adjuvant therapy for cancer pain in advanced NSCLC patients.

Simultaneous quantification of peroxidase/ascorbate in vegetables with slope and intercept of kinetic curves in a flow-injection recirculating-catalysis system.

In using a flow-injection recirculating-catalysis system developed by us to research the simultaneous quantification for peroxidase and ascorbate, it was discovered that the concentrations of peroxidase activity and ascorbate are correlative with the slope and the negative intercept of the linear response curve during a peroxidase-catalyzed kinetic course. Therefore, based on this finding, a new analytical method and a simplified equation for quantifying the peroxidase activity concentration were proposed, Then, test conditions were optimized, finally the use of the method has realized the simultaneous determination for peroxidase of 2-40 U/L and ascorbate of 0.4-12 mg/L in various vegetables (60 µL). The assayed results were consistent with the comparison method, in which the repeatability (RSD < 1.43%, n = 11) was satisfactory. Another important conclusion obtained in this study is that the determination of the peroxidase activity in biosamples must use the kinetic curve method for fear of the influence from the ascorbate's lag phase.

Highly Sensitive Lanthanide-Doped Nanoparticles-Based Point-of-Care Diagnosis of Human Cardiac Troponin I.

INTRODUCTION: Cardiac troponin I (cTnI) has been regarded as a gold standard for early diagnosis and prognosis monitoring of acute myocardial infarction (AMI) in clinical practice. Owing to its low concentration in blood, accurate determination of cTnI often requires high sensitivity. However, current established point-of-care (POC) assays are insufficient to meet clinically analytical requirements due to their low sensitivity. METHODS: To this end, we established a highly sensitive and reliable POC lateral flow strip based on lanthanide-doped nanoparticles (NPs) for cTnI determination in human blood samples. The capture of cTnI on the lateral flow strip was performed in a sandwich assay, where Eu3+-doped vanadate nanoparticles (GdVO4:30% Eu NPs) were used as luminescent probes to allow quantification. RESULTS: Our platform realized the analytical sensitivity enhancement with limit-of-detection (LOD) as low as 17 pg mL-1 for cTnI detection, which was lower than the commercial counterpart; meanwhile, it displayed high specificity, excellent reproducibility and outstanding accuracy for analyzing clinical serum samples. CONCLUSION: Overall, this strategy provided an ultrasensitive, cost-effective and user-friendly platform for on-site cTnI detection, demonstrating the prospect of lanthanide-doped NPs-based POC diagnosis of disease-related biomarkers.

Synthesis optimization of rich-urea carbon-dots and application in the determination of H2S in rich- and barren-liquids of desulphurizing solutions.

In the research of carbon dots (CDs) containing various nitrogen sources, it was first found that urea/citric acid-CDs showed a selective discolouration reaction with sulphide ions. Therefore, by optimizing various synthesis and detection conditions of the CDs determining sulfur ions, such as the raw material ratio, temperature, time, pH, and oxidation atmosphere in the CD synthesis, a discolour CD-probe method for trace-level sulphide ions was developed. The method is environmentally friendly, shows two linear-response ranges in 0.050-1.0 mg L-1 (A = -0.0827c + 0.8366) and 1.0-15 mg L-1 S2- (A = -0.0209c + 0.7587) and can be used for the high and low concentration quantification of sulphide in various wastewaters. Subsequently, in order to realize the separation and detection of sulphide ions in wastewaters or rich- and barren-liquids containing N-methyldiethanolamine and other substances in desulphurizing solutions, an automatic pretreatment system was also established.

lncRNA TSPEAR-AS2, a Novel Prognostic Biomarker, Promotes Oral Squamous Cell Carcinoma Progression by Upregulating PPM1A via Sponging miR-487a-3p.

BACKGROUND: Long noncoding RNA (lncRNA) critically impacts the modulation of tumor developments and progressions. Our study is aimed at investigating the expressing patterns, clinical significance, and biological roles of lncRNA TSPEAR-AS2 (TSPEAR-AS2) in oral squamous cell carcinoma (OSCC). Material and Approach. The expressing states achieved by TSPEAR-AS2 were examined in OSCC specimens and cell lines by RT-PCR. The clinical significance of TSPEAR-AS2 was statistically analyzed. OSCC proliferating, invading, and migrating processes were examined with the use of wound healing assays, transwell, colony formation, and cell counting kit-8. Additionally, the downstream molecular mechanism of TSPEAR-AS2 in OSCC was explored. RESULTS: TSPEAR-AS2 was overexpressed in OSCC tumors and cells. High TSPEAR-AS2 was associated with advanced TNM stage. Patients with high TSPEAR-AS2 expression displayed a shorter disease-free survival and total survival of OSCC patients than those with low TSPEAR-AS2 expressing level. It was found that knockdown of TSPEAR-AS2 could inhibit the proliferating, invading, and migrating processes pertaining to OSCC cells. Luciferase reporter tests and RNA pull-down results revealed that TSPEAR-AS2 enhanced the expressions of PPM1A by regulating miR-487a-3p, and TSPEAR-AS2 could be adopted as a miR-487a-3p sponge to inhibit PPM1A expression. CONCLUSION: Our study highlighted the significance of the TSPEAR-AS2/miR-487a-3p/PPM1A axis within OSCC progression and offered a novel biomarker and novel strategies for OSCC treatments.

Enzyme-free fluorescence determination of uric acid and trace Hg(II) in serum using Si/N doped carbon dots.

A new fluorescence probe method for the detection of Hg(II) in serum was established, which has the detection limit of 3.57 nM and quantification limit of 5 nM, based on the electrostatic induced agglomeration quenching and complexation between Hg(II) and silicon-nitrogen-doped carbon nanodots (Si/N-CDs). Furthermore, the fluorescence probe also showed the satisfactory results in the determination of Hg(II) in human serum. Subsequently, take advantage of the uric acid (UA) to recover the fluorescence of the Si/N-CDs-Hg(II) complex probe, another enzyme-free ways to determine UA was developed. The complex probe can selectively detect the UA content in the 0.5-30 µM range, and its detection limit can reach 0.14 µM, which has successfully detected the UA in total serum, and the results were no significant difference comparing with the controls.

A fluorimetric and colorimetric dual-signal sensor for hydrogen peroxide and glucose based on the intrinsic peroxidase-like activity of cobalt and nitrogen co-doped carbon dots and inner filter effect.

Herein, cobalt and nitrogen co-doped carbon dots (Co-N-CDs) were fabricated via a one-pot hydrothermal approach. The obtained Co-N-CDs displayed peroxidase-like activity and fluorescence properties. It could catalyze the oxidization of guaiacol (GA) in the presence of hydrogen peroxide (H2O2), and thus, resulted in color change, accompanied by a new absorption peak in 470 nm. Owing to the inner filter effect, the oxidized product of GA (known as 2-PQ) largely absorbed the Co-N-CD fluorescence which was excited at 380 nm. Such changes in absorbance and fluorescence intensity were H2O2 concentration-dependent. Specifically, H2O2 could be generated by glucose oxidase to catalyze the oxidation of glucose, and thus, a colorimetric and fluorimetric sensor for glucose was established with high selectivity and excellent sensitivity. After the optimization of experimental conditions, this colorimetric sensor has a good linear range from 2 to 100 µM for glucose and the detection limit was 1.16 µM. Besides, the linear relationship between the fluorescence quenching value (ΔF) and the glucose concentration (0.4-40 µM) was obtained with a detection limit of 0.18 µM. Meanwhile, the proposed sensor has also been successfully applied for glucose detection in human serum samples, and the results were consistent with those of the standard method.

Prognostic significance of regional lymphadenectomy in T1b gallbladder cancer: Results from 24 hospitals in China.

BACKGROUND: Whether regional lymphadenectomy (RL) should be routinely performed in patients with T1b gallbladder cancer (GBC) remains a subject of debate. AIM: To investigate whether RL can improve the prognosis of patients with T1b GBC. METHODS: We studied a multicenter cohort of patients with T1b GBC who underwent surgery between 2008 and 2016 at 24 hospitals in 13 provinces in China. The log-rank test and Cox proportional hazards model were used to compare the overall survival (OS) of patients who underwent cholecystectomy (Ch) + RL and those who underwent Ch only. To investigate whether combined hepatectomy (Hep) improved OS in T1b patients, we studied patients who underwent Ch + RL to compare the OS of patients who underwent combined Hep and patients who did not. RESULTS: Of the 121 patients (aged 61.9 ± 10.1 years), 77 (63.6%) underwent Ch + RL, and 44 (36.4%) underwent Ch only. Seven (9.1%) patients in the Ch + RL group had lymph node metastasis. The 5-year OS rate was significantly higher in the Ch + RL group than in the Ch group (76.3% vs 56.8%, P = 0.036). Multivariate analysis showed that Ch + RL was significantly associated with improved OS (hazard ratio: 0.51; 95% confidence interval: 0.26-0.99). Among the 77 patients who underwent Ch + RL, no survival improvement was found in patients who underwent combined Hep (5-year OS rate: 79.5% for combined Hep and 76.1% for no Hep; P = 0.50). CONCLUSION: T1b GBC patients who underwent Ch + RL had a better prognosis than those who underwent Ch. Hep + Ch showed no improvement in prognosis in T1b GBC patients. Although recommended by both the National Comprehensive Cancer Network and Chinese Medical Association guidelines, RL was only performed in 63.6% of T1b GBC patients. Routine Ch + RL should be advised in T1b GBC.

A flow-injection system exploiting focused beam reflectance applied to the determination of high concentrations of sulfate.

To evaluate the grain size and particle number formed in a non-equilibrium flow mixing state, flow-injection analysis (FIA) was combined with focused beam reflectance measurement (FBRM). The influence of BaCl2, PEG-4000, ethanol, flowrate, temperature and acidity on the dynamic formation of BaSO4 particles was evaluated. Optimization parameters obtained were 5% BaCl2 as the reagent, 2% PEG-4000 + 6% ethanol as the stabilizer and 0.3 mol L-1 HCl as the carrier with 4 ml min-1 flowrate, and the BaSO4 particle size distribution in the system was in the 1-50 µm range. Under optimized conditions, the system was successfully used for the determination of high sulfate concentrations in the wet-process phosphoric acid process in the 3.2-48 g L-1 (Sct = 55c + 208, r = 0.998, n = 3) range for SO42-. The relative standard deviation was less than 1.86% (n = 11), the detection limit was 0.95 g L-1, the sample throughput reached 30 samples per h, recovery data were within the 97-106% range, and the results were consistent with those of gravimetry (RD < 3%). The system avoids the large error caused by high dilution and the slow analysis speed when measuring high sulfate concentrations.

A flow injection fluorescence "turn-on" sensor for the determination of metformin hydrochloride based on the inner filter effect of nitrogen-doped carbon dots/gold nanoparticles double-probe.

In this paper, an ultrasensitive and rapid "turn-on" fluorescence sensor, integrating flow-injection (FI) with nitrogen-doped carbon dots/gold nanoparticles (N-CDs/AuNPs) double-probe is established for the determination of metformin hydrochloride (MET) in biological fluids. The sensing strategy involves the weak inner filter effect between AuNPs and N-CDs due to aggregation products of MET with AuNPs. Unfortunately, the degree of AuNPs aggregation is difficult to control through manual assays, resulting in intolerable measurement error that limits further applications. However, the proposed method overcomes the above problem, and significantly lowers the consumption of expensive reagents (AuNPs: about 60 µL per test). Under optimal conditions, the fluorescence intensity at 400 nm excitation and 505 nm emission wavelengths display a linear correlation with MET concentration (5-100 µg L-1) and the limit of detection is 2.32 µg L-1 (3.3 S/k). The advantages of the presented method include high sensitivity, rapid speed (60 sample h-1), good accuracy and precision (RSD ≤ 2.1%, n = 11) and low cost. Since MET is the first-line hypoglycemic agent in patients with type II diabetes, this method can preliminarily determine MET content in urine samples, giving satisfactory results.