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A sensitive polymer dots fluorescent sensor for determination of α-L-fucosidase activity in human serum
摘要： α-L-Fucosidase (AFu) is an important biomarker for early diagnosis of hepatocellular carcinoma and fucosidosis. In this study, a novel, sensitive and selective polymer dots (PDs) fluorescent sensing strategy based on inner filter effect was firstly developed for AFu activity determination. The PDs with a high quantum yield of 53.6% were synthesized by a mild one-pot method. The detection mechanism of this strategy was based on inner filter effect between PDs and p-nitrophenol (PNP) which was the hydrolyzate of 4-nitrophenyl-α-L-fucopyranoside (PNPF) catalyzed by AFu. The absorption of PNP overlapped the fluorescence excitation spectrum of the PDs, which resulted in a fluorescence quenching or weakening of PDs. The sensing system showed a good linear relationship within 0.01-0.9 U L-1 and provided a low AFu detection limit of 0.001 U L-1 (S/N=3). This PDs sensor were successfully applied for the determination of AFu in human serum samples.
关键词： Human serum,α-L-Fucosidase,Polymer dots,Inner filter effect,Fluorescent sensor
更新于2025-11-19 16:46:39
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Dopamine Binding and Analysis in Undiluted Human Serum and Blood by the RNA-Aptamer Electrode
摘要： Specific analysis of such neurotransmitters as dopamine by the aptamer electrodes in biological fluids is detrimentally affected by non-specific adsorption of media, particularly pronounced at positive charges of the electrode surface at which dopamine oxidizes. Here, we show that dopamine analysis at the RNA-aptamer/cysteamine-modified electrodes is strongly inhibited in undiluted human serum and blood due to non-specific interfacial adsorption of serum and blood components. We demonstrate that non-specific adsorption of serum proteins (but not of blood components) could be minimized when analysis is performed in a flow and injections of serum samples are followed by washing steps in a phosphate buffer solution (PBS) carrier. Under those conditions, the dopamine-aptamer binding affinity in whole human serum of (1.9±0.3)×104 M-1 s-1 was comparable to (3.7±0.3)×104 M-1 s-1 found in PBS, and the dopamine oxidation signal linearly depended on the dopamine concentration, providing the sensitivity of analysis of 73 ± 3 nA μM-1 cm-2 and the LOD of 114 ± 8 nM. The flow-injection apatmer-electrode system was used for direct analysis of basal levels of dopamine in undiluted human serum samples, without using any physical separators (membranes) or filtration procedures. The results suggest a simple strategy for combatting biosurface fouling most pronounced at positive electrode potentials and assist in designing more efficient antifouling strategies for biomedical applications.
关键词： Human serum,Blood,Surface fouling,RNA aptamer electrode,Dopamine,Chronoamperometry,Electrochemical Impedance,Flow-through cell
更新于2025-09-23 15:22:29
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Red emitting human serum albumin templated copper nanoclusters as effective candidates for highly specific biosensing of bilirubin
摘要： In this paper, we report a new type of human serum albumin (HSA) stabilized red emissive copper nanoclusters (HSA?CuNCs) were prepared at room temperature and HSA?CuNCs were applied to identify the bilirubin in human urine and blood serum samples. The emission characteristics of synthesized HSA?CuNCs were pH responsive to that the intensity of emission enhanced quickly with varying the pH range from 12 to 6. Emission spectral signal of HSA?CuNCs was found as reduced well with the raise in the amounts of bilirubin attributed to strong binding attraction leads to the non-fluorescent complex formation of HSA?CuNCs with bilirubin. Due to the strong affinity between the nanoprobe and analyte, the red emissive HSA?CuNCs illustrates more specific for the detection bilirubin over the different potential interfering molecules. Two good linear relationships were distinguished the relative emission intensity of HSA?CuNCs versus bilirubin concentrations range from 1.25 × 10-6 to 7.50 × 10-6 M and 5.00 × 10-6 to 2.875 × 10-5 M with lowest limit of detection was determined as 35.00 × 10-9 M and 145.00 × 10-9 M (S/N = 3), respectively. Furthermore, this methodology was effectively used in the quantification of bilirubin in clinical (real) samples. In addition, this fluorometric method offers cost-effective, easy, highly specific and ultrasensitive optical platform for the determination of bilirubin.
关键词： Red emittive,pH-responsive,human serum albumin,optical platform,bilirubin
更新于2025-09-23 15:22:29
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Protein Corona Formation of Human Serum Albumin with Carbon Quantum Dots from Roasted Salmon
摘要： As the food-borne nanoparticles enter the biological system, they will contact with various proteins to form protein coronas, which can affect their physicochemical properties and biological identity. In this study, the protein corona formation of carbon quantum dots (CQDs) from roast salmon with human serum albumin (HSA), as well as biological identity involving cell apoptosis, energy, glucose and lipid metabolism and acute toxicity in mice, were investigated. The HSA-CQD coronas formed between HSA and CQDs via static binding mechanism, and the binding site of CQDs on HSA located both in Sudlow’s site I and site II. The HSA-CQD coronas entered the cytoplasm and present in lysosomes or autolysosomes. Importantly, the HSA coronas mitigated the cytotoxicity of CQDs from 18.65% to 9.26%, and the energy metabolism was rectified from glycolytic to aerobic metabolism. The glucose and lipid metabolite profile of the HSA-CQD coronas differed from that of the CQDs, indicating that HSA-CQD coronas rectified disturbance in metabolism. Histopathological and blood biochemical analysis revealed no statistically significant difference between the testing and control mice after a single CQDs dose of 2000 mg/kg body weight. Overall, the results confirmed the formation of protein corona between HSA and food-borne fluorescent CQDs, and could be helpful for evaluating the safety of fluorescent CQDs from roast food items.
关键词： cytotoxicity,acute toxicity,protein coronas,human serum albumin,carbon quantum dots,metabolism,food-borne nanoparticles
更新于2025-09-23 15:21:01
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Fluorometric immunoassay for the simultaneous determination of the tumor markers carcinoembryonic antigen and cytokeratin 19 fragment using two kinds of CdSe/ZnS quantum dot nanobeads and magnetic beads
摘要： A method is described for the simultaneous determination of the carcinoembryonic antigen (CEA) and cytokeratin 19 fragment (CYFRA21-1). Two kinds of CdSe/ZnS quantum dot nanobeads (QBs), with emission maxima at 530 nm (green) and 585 nm (yellow), were used as labels, and magnetic beads (MBs) for separation. The MBs were used as substrates to couple CEA and CYFRA21-1 antibody for isolating the proteins. Then, the differently colored QBs were linked to the antibodies against CEA and CYFRA21-1, respectively. Following the formation of the immunocomplex, the intensities of the green and yellow emissions were measured at the same excitation wavelength of 340 nm. The detection limits are 0.1 ng·mL?1 for CEA, and of 0.2 ng·mL?1 for CYFRA21-1. The recoveries from spiked serum are 92.1 - 118.1% for CEA, and from 90.8% to 115.2% for CYFRA21-1, with the relative standard deviations of 6.3 - 12.3% and 7.1 - 11.8%. The method was successfully applied to the simultaneous determination of the two proteins in human serum sample (n = 45). The results correlated well with those of the chemiluminescent enzyme immunoassay kit.
关键词： Lung cancer,Human serum,Fluorescence,Multiplexed detection,Antibody
更新于2025-09-23 15:19:57
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Smart Assembled Human Serum Albumin Nanocarrier Enhanced Breast Cancer Treatment and Antitumor Immunity by Chemo- photothermal Therapy
摘要： High invasion and metastasis are the major obstacles to successful breast cancer therapy. Indocyanine green (ICG), a photosensitizer for photothermal therapy (PTT), shows potent anticancer efficacy when combined with the chemotherapeutic drug doxorubicin (DOX). Human serum albumin (HSA), a biocompatible carrier material, has been successfully used for the delivery of paclitaxel (Abraxane). In addition, there are ICG functional binding regions in HSA. Thus, a smart assembled nanoplatform (DI@HSA NPs) was constructed to achieve the synergistic effects of chemo-photothermal therapy against breast cancer. Compared to free ICG and free DOX, DI@HSA NPs showed satisfactory stability and exhibited an enhanced tumor targeting capacity. The mild hyperthermia generated by DI@HSA NPs can not only cause tumor photothermal ablation and promote the uptake of DI@HSA NPs by 4T1 cells, but also protect the healthy tissues nearby the tumor from overheating injury. More importantly, DI@HSA NPs greatly amplified the infiltration of CD4+ T cells and CD8+ T cells, resulting in inhibited tumor growth and metastasis. DI@HSA NPs, as a simple biocompatible nanoagent, showed excellent inhibition of breast cancer growth and metastasis by chemo-photothermal therapy, providing a potential strategy for the future therapy of breast cancer.
关键词： chemo-photothermal therapy,human serum albumin,tumor metastasis,antitumor immunity
更新于2025-09-23 15:19:57
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Combination of light-driven co-delivery of chemodrugs and plasmonic-induced heat for cancer therapeutics using hybrid protein nanocapsules
摘要： Background: Improving the water solubility of hydrophobic drugs, increasing their accumulation in tumor tissue and allowing their simultaneous action by different pathways are essential issues for a successful chemotherapeutic activity in cancer treatment. Considering potential clinical application in the future, it will be promising to achieve such purposes by developing new biocompatible hybrid nanocarriers with multimodal therapeutic activity. Results: We designed and characterised a hybrid nanocarrier based on human serum albumin/chitosan nanoparticles (HSA/chitosan NPs) able to encapsulate free docetaxel (DTX) and doxorubicin?modified gold nanorods (DOXO?GNRs) to simultaneously exploit the complementary chemotherapeutic activities of both antineoplasic compounds together with the plasmonic optical properties of the embedded GNRs for plasmonic?based photothermal therapy (PPTT). DOXO was assembled onto GNR surfaces following a layer?by?layer (LbL) coating strategy, which allowed to partially control its release quasi?independently release regarding DTX under the use of near infrared (NIR)?light laser stimulation of GNRs. In vitro cytotoxicity experiments using triple negative breast MDA?MB?231 cancer cells showed that the developed dual drug encapsulation approach produces a strong synergistic toxic effect to tumoral cells compared to the administration of the combined free drugs; additionally, PPTT enhances the cytostatic efficacy allowing cell toxicities close to 90% after a single low irradiation dose and keeping apoptosis as the main cell death mechanism. Conclusions: This work demonstrates that by means of a rational design, a single hybrid nanoconstruct can simultaneously supply complementary therapeutic strategies to treat tumors and, in particular, metastatic breast cancers with good results making use of its stimuli?responsiveness as well as its inherent physico?chemical properties.
关键词： Multimodal therapy,Gold nanorods,Photo?therapy,Stimuli?responsiveness,Human serum albumin nanoparticles
更新于2025-09-19 17:13:59
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Degradation of Human Serum Albumin by Infrared Free Electron Laser Enhanced by Inclusion of a Salen-Type Schiff Base Zn (II) Complex
摘要： A salen‐type Schiff base Zn(II) complex included in human serum albumin (HSA) protein was examined by UV‐Vis, circular dichroism (CD), and fluorescence (PL) spectra. The formation of the composite material was also estimated by a GOLD program of ligand–protein docking simulation. A composite cast film of HSA and Zn(II) complex was prepared, and the effects of the docking of the metal complex on the degradation of protein molecules by mid‐infrared free electron laser (IR‐FEL) were investigated. The optimum wavelengths of IR‐FEL irradiation to be used were based on experimental FT‐IR spectra and vibrational analysis. Using TD‐DFT results with 6‐31G(d,p) and B3LYP, the IR spectrum of Zn(II) complex could be reasonably assigned. The respective wavelengths were 1652 cm?1 (HSA amide I), 1537 cm?1 (HSA amide II), and 1622 cm?1 (Zn(II) complex C=N). Degradation of HSA based on FT‐IR microscope (IRM) analysis and protein secondary structure analysis program (IR‐SSE) revealed that the composite material was degraded more than pure HSA or Zn(II) complex; the inclusion of Zn(II) complex enhanced destabilization of folding of HSA.
关键词： IR‐FEL,TD‐DFT,human serum albumin,Schiff base,fluorescence,Zn(II) complex
更新于2025-09-19 17:13:59
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Biocompatible Palladium Telluride Quantum Dot-Amplified Biosensor for HIV Drug
摘要： Indinavir (IDV) is a potent and well-tolerated protease inhibitor antiretroviral (ARV) drug used as a component of the highly active antiretroviral therapy (HAART) of human immunodeficiency virus (HIV). It undergoes hepatic first-pass metabolism that is catalysed by microsomal cytochrome P450-3A4 enzyme (CYP3A4), which results in pharmacokinetics that may be favourable or adverse. Therapeutic drug monitoring (TDM) of IDV during HIV treatment is therefore critical, in order to prevent the adverse effects of its first-pass metabolism and optimise an individual’s dosage regime. Biosensors are now the preferred diagnostic tools for TDM assessment at point-of-care, due to their high sensitivity and real-time response. An electrochemical biosensor for IDV was prepared by depositing a thin film of CYP3A4 (a thiolate enzyme) and thioglycolic acid-capped palladium telluride quantum dot (TGA-PdTeQD) on a cysteamine-functionalised gold disk electrode (Cyst|Au) using a combination of thiol and carbodiimide covalent bonding chemistries. The electrochemical signatures of the biosensor (CYP3A4|TGA-PdTeQD|Cyst|Au) were determined by cyclic voltammetry (CV) that was performed at a scan rate of 500 mV s?1, and the sensor responses at the characteristic reduction peak potential value of ? 0.26 V were recorded. The sensitivity, linear range (LR) and limit of detection (LOD) values of the indinavir biosensor were 4.45 ± 0.11 μA nM?1 IDV, 0.5–1.0 nM IDV (i.e. 3.6 × 10?4–7.1 × 10?4 mg L?1 IDV) and 4.5 × 10?4 mg L?1 IDV, respectively. The values of the two analytical parameters (LR and LOD) of the biosensor were by up to four orders of magnitude lower than the maximum plasma concentration (Cmax) values of indinavir (0.13–8.6 mg L?1 IDV). The IDV biosensor was successfully used to detect IDV in human serum samples containing dissolved indinavir tablet. This, therefore, indicates the indinavir biosensor’s suitability for TDM applications, using samples obtained within 1–2 h of drug intake at point-of-care, for which very low levels of the drug are expected.
关键词： Human serum,Limit of detection,Indinavir,Palladium telluride quantum dot,Cyclic voltammetry,Electrochemical sensors,Cytochrome P450-3A4
更新于2025-09-16 10:30:52
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Fluorescence immunoassay of E. coli using anti-lipopolysaccharide antibodies isolated from human serum
摘要： In this work, the gram-negative bacterium Escherichia coli strain BL21(DE3) (with lipopolysaccharide (LPS) in its outer membrane) and its modified ClearColi? strain (lacking LPS) were used for the separation of anti-LPS antibodies from human serum by the following steps: (1) binding of the serum proteins to BL21(DE3); (2) dissociation of the bound proteins (including anti-LPS antibodies) from BL21(DE3) with acid; (3) filtering of the dissociated proteins using ClearColi to remove unwanted proteins; and (4) separation of the antibody fraction by protein-A column chromatography. The binding properties of the separated antibodies were analyzed by fluorescence-activated cell sorting to confirm their selective binding to LPS on the outer membrane of BL21(DE3), and by thermophoretic immunoassay to estimate their dissociation constant. The in vitro applicability of the separated anti-LPS antibodies was demonstrated through a fluorescence assay of BL21(DE3), after immobilizing the antibodies onto a modified microplate surface. The electrochemical detection of BL21(DE3) was also achieved after immobilizing the anti-LPS antibodies onto a gold electrode.
关键词： Separation,Anti-LPS antibody,LPS,ClearColi,Human serum
更新于2025-09-10 09:29:36