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Determination of prostate cancer biomarker acid phosphatase at a copper phthalocyanine-modified screen printed gold transducer
摘要： In this work, a novel sensor based on immobilized copper phthalocyanine, 2,9,16,23-tetracarboxylic acid-polyacrylamide (Cu(II)TC Pc-PAA) was developed for determination of acid phosphatase (ACP) levels in nanomolar quantities. Detection was based on the measurement of enzymatically generated phosphate, with initial studies focused on phosphate detection at a Cu(II)TC Pc-PAA modified screen-printed gold transducer. The sensor was characterised in relation to operational performance (pH, response time, stability, linearity, and sensitivity) and common anionic interferents (nitrate, sulphate, chloride, and perchlorate). The functionalised surface also facilitated rapid detection of the enzyme bi-product 2-naphthol over the range 5-3000 μM. Quantitation of ACP was demonstrated, realising a linear response range of 0.5-20 nM and LOD of 0.5 nM, which is within the clinical range for this prostate cancer biomarker.
关键词： phosphate,Copper phthalocyanine,acid phosphatase,naphthol,gold screen-printed electrode.
更新于2025-09-23 15:23:52
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Digital LAMP on a Commercial Membrane
摘要： In this work, we report digital loop-mediated isothermal amplification (LAMP) or reverse-transcription LAMP (RT-LAMP) on a commercial membrane, without the need for complex chip fabrication or use of specialized equipment. Due to the pore size distribution, the theoretical error for digital LAMP on these membranes was analyzed, using a combination of Random Distribution Model and Multi-volume Theory. A facile peel-off process was developed for effective droplets formation on the commercial track-etched polycarbonate (PCTE) membrane. Each pore functions as an individual nanoreactor for single DNA amplification. Absolute quantification of bacteria genomic DNA was realized with a dynamic range from 11 to 1.1 × 10^5 copies/μL. One-step digital RT-LAMP was also successfully performed on the membrane for the quantification of MS2 virus in wastewater. With the introduction of new probes, the positive pores can be easily distinguished from negative ones with 100 times difference in fluorescence intensities. Finally, the cost of a disposable membrane is less than $0.1/piece, which, to the best of our knowledge, is the most inexpensive way to perform digital LAMP. The membrane system offers opportunities for point-of-care users or common laboratories to perform digital quantification, single cell analysis, or other bioassays in an inexpensive, flexible and simplified way.
关键词： Digital LAMP,RT-LAMP,PCR,Droplets,Virus,Microfluidic,Membrane,Nucleic acid
更新于2025-09-23 15:23:52
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Effect of solvents on the self-assembly of long chain alkylphosphonic acids on indium tin oxide surface - In situ studies on the adsorption kinetics and electron transfer process
摘要： The spontaneous self-assembly process of phosphonic acids (PAs) onto indium tin oxide (ITO) surface has been studied in this work. We have carried out in situ adsorption kinetics studies of phosphonic acids in ethanol as a solvent using electrochemical impedance spectroscopy (EIS). Further, the effect of different solvents like ethanol, water, toluene and hexane on the structural integrity of the alkylphosphonic acid (CH3 (CH2)n PO3H2, n = 15,17) thin films on ITO surface has been investigated by using [Fe(CN)6]3-/4- as a redox probe. From the study of formation kinetics, it is concluded that molecular self-assembly process follows two adsorption steps, a fast first step followed by a slower second step. The results of cyclic voltammetric (CV) and impedance measurements show that phosphonic acids form a highly impermeable surface film on ITO when polar solvents like ethanol and water are used.
关键词： self assembly,Adsorption Kinetics,microelectrode array,Contact Angle,Capacitance,ITO,Phosphonic acid
更新于2025-09-23 15:23:52
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Gas adsorption and Fluorescent Sensing Properties of Three Metal-Organic Frameworks Based on 3,5-di(2’,5’-dicarboxylphenyl)benozoic Acid and Cadmium Ions
摘要： Three 3D Cd(Ⅱ) metal-organic frameworks(MOFs), namely, {[Cd3(L)(OH)(H2O)3]n·2H2O} (1), {Cd5(L)2(H2O)9}n (2) and {Cd2(L)(bib)(NH4)}n (3), have been synthesized based on H5L and cadmium ion under hydrothermal conditions (H5L = 3,5-di(2’,5’-dicarboxylpyl)benozoic acid, bib = 1,4-bis(1-imidazoly)benzene), and characterized by IR spectrum analysis, powder X-ray diffraction analysis (PXRD) and thermogravimetric analysis (TGA). X-ray single crystal diffraction analyses showed that complex 1 is a porous 3D 4-connected net with the point symbol of {4.65} with the trinuclear [Cd3(OH)(COO)5] SBUs, complex 2 displays a 3D framework 7-connected net with the point symbol of {33.412.55.6} with the pentanuclear [Cd5(COO)10(H2O)9] SBUs and complex 3 presents a porous 3D 4,6-connected net with the point symbol of {43.610.82}{43.63}. Furthermore, fluorescent measurements indicated that 1 and 2 have potential application in the detection for Fe3+, CrO4 2- and Cr2O7 2- ions in aqueous solution. Gas sorption properties exhibited that complex 1 has better hydrogen storage performance.
关键词： Luminescent properties,3,Gas adsorption,5–di(2’,5’-dicarboxylphenyl)benozoic acid
更新于2025-09-23 15:23:52
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H-complexes in the “4-n-alkoxybenzoic acid: 4-pyridyl 4′-n-alkoxybenzoate” system. IR spectroscopy and quantum chemical calculations
摘要： IR spectra of individual 4-n-dodecyloxybenzoic acid (A) and 4-pyridyl 4'-n-dodecyloxybenzoate (B) compounds as well as IR spectra of 2A:1B and 1A:1B systems were recorded. For the assignment of the experimental vibrational spectra a series of quantum chemical calculations of DFT(B97-D)/6-311++G** level was carried out. Hydrogen-bonded complexes of types A···A, A···B, as well as various trimers that can be formed at different component ratios in system A-B were simulated. The geometric structure of these complexes was optimized and the vibrational frequencies were calculated. The conclusions on the molecular organization of system A-B for different ratios of the components A and B were based on the interpretation of IR spectra and the analysis of calculated thermodynamic characteristics of self-assembly processes. Thus, it is determined that the system A consists of cyclic A···Acycl dimers; in 1A:1B system the H-complexes of A···B type are formed. In the 2A:1B system in the process of self-assembly, instead of the complexes A···A···B and A···B···A of stoichiometric composition, the complexes A···B and A···Acycl are formed in the ratio 2:1. These results are confirmed by the dilatometric method data.
关键词： thermodynamic characteristics,4-pyridyl 4'-n-alkoxybenzoate,DFT,IR spectra,self-assembly,4-n-alkoxybenzoic acid,hydrogen bonded complexes
更新于2025-09-23 15:23:52
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Plum-blossom needle assisted photodynamic therapy: The therapy option for the treatment of oral potentially malignant disorder in the elderly
摘要： Oral leukoplakia (OLK) is one of the most common oral potentially malignant disorders (OPMD) with complex causes, a long disease course and a high tendency for recrudescence. Although a variety of methods exist for treating this disease, canceration rates remain high. Herein, we described a case of 72-year-old male patient with OLK of the palatine mucous membrane who had achieved complete remission after being treated with five sessions of plum-blossom needle (PBN) assisted 5-aminolevulinic acid-photodynamic therapy (ALA-PDT). The patient had since been subsequently placed under close observation (>12 mo). To date, there has been no recurrence. PBN assisted PDT might be suitable for the treatment of OPMDs in patients presenting with epithelial hyperkeratosis.
关键词： Plum-blossom needle,Oral potentially malignant disorders,Photodynamic therapy,Aminolevulinic acid,Hyperkeratosis,Oral leukoplakia
更新于2025-09-23 15:23:52
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Facile method for iodide ion detection via the fluorescence decrease of dihydrolipoic acid/beta-cyclodextrin protected Ag nanoclusters
摘要： In this work, novel photoluminescent Ag nanoclusters (Ag NCs) with red emission are synthesized and successfully used for detecting iodide ion (I?). The dihydrolipoic acid (DHLA) is used as the stabilizing agent and beta-cyclodextrin (β-CD) is used as the auxiliary stabilizing agent. DHLA and β-CD are combined with Ag atoms by the formation of Ag-S bonds and hydrophobic interaction, respectively. Functionalization of β-CD endows good photoluminescent properties and solubility in water to the Ag NCs. The obtained DHLA and β-CD-protected Ag NCs (DHLA/β-CD-Ag NCs) are spherical and display a dispersed state. However, the DHLA/β-CD-Ag NCs are aggregated in the presence of I?, accompanied by the decrease in their fluorescence intensity. Because the integrity of β-CD cavities is retained on the surface of DHLA/β-CD-Ag NCs, which preserves their capability for I? host–guest recognition, the DHLA/β-CD-Ag NCs combine with I? through the formation of inclusion complexes. Based on this phenomenon, the prepared DHLA/β-CD-Ag NCs can be designed as a novel fluorescent probe for I? detection. The limit of detection (LOD) is calculated as 0.06 μM, indicating that it is an ideal probe for I? detection in practical applications.
关键词： Ag nanoclusters,Fluorescent probe,Beta-cyclodextrin,Dihydrolipoic acid,Iodide ion
更新于2025-09-23 15:23:52
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Quantification of Glucose via in situ Growth of Cu2O/Ag Nanoparticles
摘要： The monitoring of glucose levels in blood is extremely important for the effective control of diabetes. Nanomaterial-based approaches for the quantification of glucose typically require two steps: material preparation and the actual glucose measurement. Herein, we report a single-step method that combines these functions via the in situ growth of Cu2O/Ag nanoparticles (NPs). Mechanistically, we use glucose itself to reduce Cu2+ and Ag+ ions that are stabilized with 3-mercaptopropionic acid (3-MPA) and bovine serum albumin (BSA) under alkaline conditions to form Cu2O/Ag NPs and produce a color change in solution due to plasmonic resonance at 400 nm, which can be related back to the concentration of glucose. We study several factors in this reaction, including the molar ratios of the metal ions and 3-MPA, the reaction time, and the temperature to control the synthesis of the Cu2O/Ag NPs and thus their sensitivity toward glucose. Introducing BSA into the system is a key factor for the quantification of glucose in blood without pretreatment, improving the probe’s limit of detection and reducing the sample volumes to 1 μL. This colorimetric assay based on Cu2O/Ag NPs exhibits excellent sensitivity and specificity toward glucose, and a linear relationship with glucose concentrations ranging from 15 to 300 μM and a limit of detection of 9.2 μM. As proof of concept, we demonstrated that the Cu2O/Ag NP probes could successfully detect glucose in two representative blood samples by neglecting interferences from various common species, demonstrating the potential of this technique in point-of-care analysis.
关键词： plasmonic resonance,3-mercaptopropionic acid,bovine serum albumin,silver nanoparticles,glucose quantification,Cu2O
更新于2025-09-23 15:23:52
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An alternative, single-point method for creatinine determination in urine samples with optoelectronic detector. Critical comparison to Jaffé method
摘要： A rapid, single-point method for colorimetric creatinine determination has been developed as an alternative for a well-established Jaffé assay, which lacks analytical specificity. 3,5-dinitrobenzoic acid was employed in an alkaline environment as a chromophore instead of picric acid. Apart from the spectrophotometer, a simple optoelectronic detector was applied as an alternative detection method. The conditions of the reaction were optimized to provide satisfactory analytical parameters. The linear ranges of the proposed assays were 40–4000 and 10–300 μmol L?1 of creatinine for conventional spectrophotometry and a PEDD detector, respectively. A broad spectrum of potential interferents was examined. The presence of compounds such as glucose, urea or uric acid was the source of a significantly smaller bias in the examined method than in the case of the Jaffé method variants. The presented method was validated with the use of 10 human urine samples with the creatinine level determined by the recommended method. Two-tail paired Student's t-tests with 9 degrees of freedom at the 95% confidence level showed the agreement between the proposed and the reference methods.
关键词： 3,5-dinitrobenzoic acid,Urine,Creatinine,3D-printed,Jaffé
更新于2025-09-23 15:23:52
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Hyperbaric oxygen combined with 5-aminolevulinic acid photodynamic therapy inhibited human squamous cell proliferation
摘要： The photodynamic therapy (PDT) depends on the presence of molecular oxygen. Thus, the efficiency of PDT is limited in anoxic regions of tumor tissue and vascular shutdown. It is reported the use of hyperbaric oxygen (HBO) may enhance the efficiency of PDT. However, there are rarely studies about utilizing HBO plus PDT for treatment with human squamous cell carcinoma (SCC). Therefore, this study aimed to investigate and compare the therapeutic effect of combined therapy and PDT alone treatment. Multiple cellular and molecular biology techniques were used in the current study such as CCK-8, western blotting, flow cytometry, MDC staining and immunofluorescence assay. The results of combination index indicated that HBO combination with PDT synergistically inhibited A431 cells proliferation in vitro. In addition, we found that HBO significantly enhanced PDT-induced cell apoptosis via increasing the active caspase-3, active caspase-9, Apaf-1 and Bax levels and down-regulating Bcl-2. Meanwhile, the result of MDC and immunofluorescence assay confirmed that HBO increased PDT-induced autophagosome formation in A431 cells. Interestingly, autophagy inhibitor 3-methyladenine (3-MA) further increased combination-induced cell apoptosis by increasing the levels of active-caspase 9 and Apaf-1. Our results showed that HBO combined with PDT markedly induced A431 cells apoptosis and autophagy. Nevertheless, autophagy play a pro-survival role against apoptosis. Thus, HBO combination with PDT may constitute a promising approach to treat human squamous cell carcinoma in the future.
关键词： human squamous cell carcinoma,5-aminolevulinic acid photodynamic therapy,apoptosis,autophagy,hyperbaric oxygen
更新于2025-09-23 15:23:52