111,416 results
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2. Colorimetric and electrochemical dual-signal detection of uracil-DNA glycosylase using functionalized pure DNA hydrogel on paper-based analytical devices
- Author
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Wei Xue, Pan Jia, Yunping Wu, Pu Wang, Jiarong Shi, Yangyang Chang, and Meng Liu
- Subjects
Pure DNA hydrogel ,Uracil-DNA glycosylase ,Dual-signal detection ,Rolling circle amplification ,Paper-based analytical device ,Agriculture (General) ,S1-972 ,Biochemistry ,QD415-436 ,Chemistry ,QD1-999 - Abstract
The development of simple and accurate detection of uracil-DNA glycosylase (UDG) is of great significance for early clinical diagnosis and biomedical research. Here, we on the first effort introduced the uracil bases into the rolling circle amplification (RCA) reaction to produce the functionalized pure DNA hydrogel (PDH) for UDG detection. During RCA process, methylene blue (MB) molecules as the indicators were encapsulated into PDH. The addition of UDG can remove the uracil bases of PDH to generate abasic sites, which are further cleaved with the assistance of apurinic/apyrimidinic endonuclease (APE), thus resulting in the dissociation of PDH to release blue MB. By combining with the paper analytical devices as the signal readout platform, a colorimetric and electrochemical dual-signal biosensor was constructed for convenient and accurate detection of UDG. The proposed MB@PDH-based dual-signal sensing system exhibited good selectivity and high sensitivity with a detection limit of 6.4 × 10−4 U/mL (electrochemical method). It was also demonstrated that this sensing system showed excellent performance in UDG inhibitor screening, thus providing great potential in UDG-related disease diagnosis and drug discovery.
- Published
- 2023
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3. Portable and Visual Detection of Cytochrome c with Graphene Quantum Dots–Filter Paper Composite
- Author
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Liangtong Li, Yongjian Jiang, Ni Wang, Yusheng Feng, Binbin Chen, and Jian Wang
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graphene quantum dots ,cytochrome c ,apoptosis ,inner filter effect ,portable ,filter paper ,Biochemistry ,QD415-436 - Abstract
As a significant biomarker during the apoptosis process, cytochrome c (Cyt c) is considered as a critical component in the inherent apoptotic pathway, but the simple and portable detection still remains challengeable. In this work, a portable and visual sensing platform for Cyt c was developed based upon the fluorescence quenching of graphene quantum dots (GQDs), which could be finished within a few seconds. Herein, the absorption spectrum of Cyt c matched the emission spectrum of GQDs well, which could cause the fluorescence quenching of GQDs via the inner filter effect (IFE) in the range of 1–50 μg/mL with the limit of detection as low as 0.1 μg/mL. Furthermore, the intracellular Cyt c was imaged to observe the apoptosis process of cancer cells induced by staurosporine. To achieve the portable and visual detection of Cyt c, GQDs were deposited on the filter paper to form the solid platform, which displayed a gradual fluorescence quenching when different concentrations of Cyt c were present. Compared to the conventional methods, the proposed assay is low-cost, fast, portable, and visual, which will be useful for the investigation of mitochondrial dysfunction and apoptotic cell death.
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- 2024
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4. Supramolecular systems based on chitosan and chemically functionalized nanocelluloses as protective and reinforcing fillers of paper structure
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Lorenzo Lisuzzo, Giuseppe Cavallaro, Giuseppe Lazzara, and Stefana Milioto
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Nanocellulose ,Chitosan ,Electrostatic Interactions ,ITC ,Paper consolidation ,Biochemistry ,QD415-436 - Abstract
Supramolecular systems based on chitosan and cellulose nanofibers (CNFs) with a different surface modification (TEMPO-oxidation and carboxymethylation) were investigated and utilized for the functional consolidation of paper. Prior to the paper consolidation, the interactions between chitosan and CNFs dispersed in aqueous solvent were studied. It was detected that the peculiar surface functionalization of nanocellulose is crucial to control the chitosan/CNFs electrostatic attractions and, consequently, the entropic/enthalpic contributions and the stoichiometry of the biopolymer adsorption onto the cellulose nanofibers. Dynamic Light Scattering and rheological experiments revealed that the presence of biopolymeric chains on the CNFs surface favors the entanglement and the aggregation between the nanofibers reinforcing their network. It was observed that chitosan and nanocellulose exhibit synergetic effects on the paper consolidation in terms of reinforcing action, surface hydrophobization and enhancement of the fire-resistance. In conclusion, this paper demonstrates that the electrostatic interactions between chitosan and functionalized nanocellulose drive the formation of hybrid fillers suitable for paper consolidation. Chitosan coated CNFs possess an improved capacity to penetrate the paper structure causing an enhancement of the mechanical resistance and surface hydrophobization. Moreover, chitosan/CNFs create a protective barrier for heat transfer that prevents the paper combustion.
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- 2023
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5. My 100th JBC paper.
- Author
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Sancar A
- Subjects
- History, 20th Century, History, 21st Century, Humans, Periodicals as Topic history, Biochemistry history
- Abstract
Nobel laureate Aziz Sancar writes about his decades-long relationship with the Journal of Biological Chemistry. Since 1984, he has published 100 papers in JBC, including this "Reflections.", Competing Interests: Conflict of interest The author declares no conflict of interest with the contents of this article., (Copyright © 2020 The Author. Published by Elsevier Inc. All rights reserved.)
- Published
- 2021
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6. Protein Science Best Paper awards to Tatsuya Niwa, Qingping Xu, and Matthew Biancalana.
- Subjects
- Humans, Portraits as Topic, Awards and Prizes, Biochemistry, Protein Biosynthesis, Protein Folding
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- 2020
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7. Origami Paper-Based Electrochemical Immunosensor with Carbon Nanohorns-Decorated Nanoporous Gold for Zearalenone Detection
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Anabel Laza, Sirley V. Pereira, Germán A. Messina, Martín A. Fernández-Baldo, Julio Raba, Matías D. Regiart, and Franco A. Bertolino
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paper-based ,electrochemical ,immunosensor ,carbon nanohorns ,nanoporous gold ,mycotoxin ,Biochemistry ,QD415-436 - Abstract
Nowadays, mycotoxin contamination in cereals and wastewater exposes a safety hazard to consumer health. This work describes the design of a simple, low-cost, and sensitive origami microfluidic paper-based device using electrochemical detection for zearalenone determination. The microfluidic immunosensor was designed on a paper platform by a wax printing process. The graphitized carbon working electrode modified with carbon nanohorns-decorated nanoporous gold showed a higher surface area, sensitivity, and adequate analytical performance. Electrodes were characterized by scanning electron microscopy, energy-dispersive spectroscopy, and cyclic voltammetry. The determination of zearalenone was carried out through a competitive immunoassay using specific antibodies immobilized by a covalent bond on the electrode surface. In the presence of HRP-labeled enzyme conjugate, substrate, and catechol, zearalenone was detected employing the developed immunosensor by applying −0.1 V to the working electrode vs silver as a pseudo-reference electrode. A calibration curve with a linear range between 10 and 1000 µg Kg−1 (R2 = 0.998) was obtained, and the limit of detection and quantification for the electrochemical immunosensor were 4.40 and 14.90 µg Kg−1, respectively. The coefficient of variation for intra- and inter-day assays was less than 5%. The selectivity and specificity of the sensor were evaluated, comparing the response against zearalenone metabolites and other mycotoxins that could affect the corn samples. Therefore, origami is a promising approach for paper-based electrochemical microfluidic sensors coupled to smartphones as a rapid and portable tool for in situ mycotoxins detection in real samples.
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- 2024
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8. Proceedings of International Conference on Research in Education and Science (Antalya, Turkey, April 1-4, 2021). Volume 1
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International Society for Technology, Education and Science (ISTES) Organization, Shelley, Mack, Chiang, I-Tsun, and Ozturk, O. Tayfur
- Abstract
"Proceedings of International Conference on Research in Education and Science" includes full papers presented at the International Conference on Research in Education and Science (ICRES) which took place on April 1-4, 2021 in Antalya, Turkey. The aim of the conference is to offer opportunities to share ideas, to discuss theoretical and practical issues and to connect with the leaders in the fields of education and science. The conference is organized annually by the International Society for Technology, Education, and Science (ISTES). The ICRES invites submissions which address the theory, research or applications in all disciplines of education and science. The ICRES is organized for: faculty members in all disciplines of education and science, graduate students, K-12 administrators, teachers, principals and all interested in education and science. After peer-reviewing process, all full papers are published in the Conference Proceedings. [Individual papers are indexed in ERIC.]
- Published
- 2021
9. Proceedings of International Conference on Research in Education and Science (Antalya, Turkey, April 1-4, 2021). Volume 1
- Author
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International Society for Technology, Education and Science (ISTES) Organization, Shelley, Mack, Chiang, I-Tsun, and Ozturk, O. Tayfur
- Abstract
"Proceedings of International Conference on Research in Education and Science" includes full papers presented at the International Conference on Research in Education and Science (ICRES) which took place on April 1-4, 2021 in Antalya, Turkey. The aim of the conference is to offer opportunities to share ideas, to discuss theoretical and practical issues and to connect with the leaders in the fields of education and science. The conference is organized annually by the International Society for Technology, Education, and Science (ISTES). The ICRES invites submissions which address the theory, research or applications in all disciplines of education and science. The ICRES is organized for: faculty members in all disciplines of education and science, graduate students, K-12 administrators, teachers, principals and all interested in education and science. After peer-reviewing process, all full papers are published in the Conference Proceedings.
- Published
- 2021
10. Advancing Paper Industry Applications with Extruded Cationic Wheat Starch as an Environmentally Friendly Biopolymer
- Author
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Ahmed Tara
- Subjects
cationic wheat starch ,twin-screw reactive extrusion ,degree of substitution ,papermaking ,specific mechanical energy ,viscosity ,Biochemistry ,QD415-436 - Abstract
Within the domain of starch modification, the study delved into cationization of wheat starch through a laboratory-scale twin-screw extruder, exploring various processing conditions. Cationic starch, a crucial component for enhancing paper attributes like dry strength and printability, took center stage. The focus shifted towards integration into papermaking, investigating the transformative potential of reactive extrusion. By contrasting it with conventional dry-process methodology, innovative strides were unveiled. The study extended to pilot-scale extrusion, bridging the gap between laboratory experimentation and potential industrial implementation. Infused with scientific rigor, the investigation navigated the benefits brought about by reactive extrusion. Empirical insights highlighted a significant reduction in the intrinsic viscosity of extruded starch, decreasing from 170 mL·g−1 (native starch) to 100 mL·g−1 at a specific mechanical energy (SME) input of 800 kWh·t−1, demonstrating remarkable stability despite increased mechanical treatment. Moreover, beyond the critical threshold of 220 kWh·t−1, retention efficiency reached a stable plateau at 78%. The study revealed that utilizing a larger extruder slightly improved the mechanical properties of the paper, emphasizing the advantage of scaling up the production process and the consistency of results across different extruder sizes.
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- 2023
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11. Where do we aspire to publish? A position paper on scientific communication in biochemistry and molecular biology.
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Baptista MS, Alves MJM, Arantes GM, Armelin HA, Augusto O, Baldini RL, Basseres DS, Bechara EJH, Bruni-Cardoso A, Chaimovich H, Colepicolo Neto P, Colli W, Cuccovia IM, Da-Silva AM, Di Mascio P, Farah SC, Ferreira C, Forti FL, Giordano RJ, Gomes SL, Gueiros Filho FJ, Hoch NC, Hotta CT, Labriola L, Lameu C, Machini MT, Malnic B, Marana SR, Medeiros MHG, Meotti FC, Miyamoto S, Oliveira CC, Souza-Pinto NC, Reis EM, Ronsein GE, Salinas RK, Schechtman D, Schreier S, Setubal JC, Sogayar MC, Souza GM, Terra WR, Truzzi DR, Ulrich H, Verjovski-Almeida S, Winck FV, Zingales B, and Kowaltowski AJ
- Subjects
- Brazil, Humans, Periodicals as Topic standards, Periodicals as Topic trends, Biochemistry, Molecular Biology, Periodicals as Topic statistics & numerical data, Publishing trends, Research
- Abstract
The scientific publication landscape is changing quickly, with an enormous increase in options and models. Articles can be published in a complex variety of journals that differ in their presentation format (online-only or in-print), editorial organizations that maintain them (commercial and/or society-based), editorial handling (academic or professional editors), editorial board composition (academic or professional), payment options to cover editorial costs (open access or pay-to-read), indexation, visibility, branding, and other aspects. Additionally, online submissions of non-revised versions of manuscripts prior to seeking publication in a peer-reviewed journal (a practice known as pre-printing) are a growing trend in biological sciences. In this changing landscape, researchers in biochemistry and molecular biology must re-think their priorities in terms of scientific output dissemination. The evaluation processes and institutional funding for scientific publications should also be revised accordingly. This article presents the results of discussions within the Department of Biochemistry, University of São Paulo, on this subject.
- Published
- 2019
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12. Novel Electrochemical Sensor Based on MnO2 Nanowire Modified Carbon Paper Electrode for Sensitive Determination of Tetrabromobisphenol A
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Chunmao Zhu, Qi Wu, Fanshu Yuan, Jie Liu, Dongtian Wang, and Qianli Zhang
- Subjects
tetrabromobisphenol A ,MnO2 ,carbon paper ,modified electrode ,Biochemistry ,QD415-436 - Abstract
In this paper, a MnO2 nanowire (MnO2-NW) modified carbon paper electrode (CP) was developed as a novel electrochemical sensor for the sensitive determination of tetrabromobisphenol A (TBBPA). The MnO2 nanowire was prepared by a hydrothermal synthesis method, and the morphology and structure of MnO2 were characterized using scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The electrochemical performance of TBBPA on MnO2-NW/CP was investigated by cyclic voltammetry, and the result confirmed that MnO2-NW/CP exhibited excellent sensitivity for the determination of TBBPA due to the high specific surface area and good electrical conductivity of the nanowire-like MnO2. Moreover, the important electrochemical factors such as pH value, incubation time and modified material proportion were systematically studied to improve the determination sensitivity. The interferences from similar structure compounds on TBBPA have also been investigated. Under the optimal conditions, MnO2-NW/CP displayed a linear range of 70~500 nM for TBBPA with a detection limit of 3.1 nM. This was superior to some electrochemical methods in reference. The work presents a novel and simple method for the determination of TBBPA.
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- 2023
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13. Recent Advances and Perspectives Regarding Paper-Based Sensors for Salivary Biomarker Detection
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Cong Chen, Lulu Tian, Wen Li, Kun Wang, Qijing Yang, Jinying Lin, Tianshou Zhang, Biao Dong, and Lin Wang
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paper-based sensor ,saliva biomarker ,point of care ,Biochemistry ,QD415-436 - Abstract
Paper-based sensors overcome the drawbacks of conventional sensors in terms of their flexibility, portability, and stability compared to conventional sensors. Moreover, as a noninvasive bodily fluid, saliva contains various biomarkers related to physical status, which makes it perfectly matched with to use of paper-based sensors to manufacture a convenient and inexpensive disposable sensing device. This review focuses on the recent advances and progress in the design of paper-based salivary sensors and their applications. The first part mainly discusses various paper-based sensors and their advanced compositions, including dipstick assay, lateral flow assay, and microfluidic analytical device. Different detection methods in salivary biomarker detection are specially introduced in the secondary section, then their multiple potential applications and prospects are summarized. The sensor has excellent advantages for saliva detection, provides a reliable platform for point-of-care tests and telemedicine, and epically promotes the development of the medical Internet of Things.
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- 2023
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14. Highly Crystalline Oxidase-like MnOOH Nanowire-Incorporated Paper Dipstick for One-Step Colorimetric Detection of Dopamine
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Phan Ba Khanh Chau, Thinh Viet Dang, and Moon Il Kim
- Subjects
paper dipstick ,MnOOH nanowires ,dopamine oxidase ,nanozyme ,colorimetric biosensors ,Biochemistry ,QD415-436 - Abstract
Developing a convenient detection method for dopamine holds a significant incentive due to its high clinical significance. Herein, we synthesize crystalline MnOOH nanowires (MNWs) via a simple solvothermal treatment of KMnO4 and demonstrate that they possess excellent oxidase-like activity owing to the presence of pure Mn3+ sites on the MNWs. Particularly, MNWs catalyze the rapid oxidation of dopamine into aminochromes, which show a vivid brown color. The dopamine oxidase-like activity of MNWs follows the typical Michaelis–Mentenkinetics with excellent storage stability. Based on the affirmative catalytic features, a paper dipstick incorporating MNWs in the detection zone is constructed for the one-step colorimetric detection of target dopamine. By immersing the dipstick into the sample solution for 30 min, the sample spontaneously moves to the detection zone due to capillary force, yielding a brown color proportional to the amount of dopamine, which is quantified from an image acquired using a smartphone. With the MNW-containing solution-based assay and MNW-incorporated paper dipstick, dopamine is successfully determined with high selectivity, sensitivity, and detection precision when using spiked human serum and pharmaceutical dopamine injection samples, respectively. Successful analytical values such as the dynamic linear ranges of 3–60 μM and 0.05–7 mM are achieved with the solution-based assay and paper dipstick, respectively, along with excellent detection accuracy (95–99%) and precision (1.0–3.1%). Hence, we developed a simple and efficient nanozyme-based paper dipstick biosensor for dopamine that can be used in point-of-care testing environments.
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- 2023
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15. The Herbert Tabor Best Paper Awards: Celebrating young authors who contribute top content to JBC.
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Gierasch LM and DeMartino G
- Subjects
- Awards and Prizes, Biochemistry, Periodicals as Topic
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- 2017
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16. Correction: Wu et al. A Novel Truncated DNAzyme Modified Paper Analytical Device for Point-of-Care Test of Copper Ions in Natural Waters. Chemosensors 2022, 10, 72
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Jiayi Wu, Ming Wang, Huanhuan Hong, Jianyuan Lin, Ning Gan, and Wenchao Bi
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n/a ,Biochemistry ,QD415-436 - Abstract
The authors make the following corrections to the published paper [...]
- Published
- 2024
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17. Low-Cost, High-Sensitivity Paper-Based Bacteria Impedance Sensor Based on Vertical Flow Assay
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Yifan Long, Zhehong Ai, Longhan Zhang, Han Zhang, Jing Jiang, and Gang Logan Liu
- Subjects
paper-based electrode ,bacterial detection ,portable sensor ,on-site detection ,Biochemistry ,QD415-436 - Abstract
This study proposes a low-cost, portable paper-fluidic vertical flow assay bacterium counter with high accuracy. We designed sensors with low fabrication costs based on e-beam evaporation and three-dimensional printing based on the impedance measurement principle. Interdigitated (IDT) electrodes were coated on the filter membrane by e-beam evaporation with a shadow mask. We could print wafer-scale frames with low melting temperature three-dimensional-printing materials for confining liquid bacterial samples within the IDT sensing region. This novel fabrication technique significantly reduced the chip’s cost to less than 1% of that of silicon-based chips. Two equivalent circuit models were proposed for different concentration ranges to analyze the principle of paper-based impedance bacterial sensors. We proposed an improved model based on the Randles model for low concentrations by considering the leaky double-layer capacitor effect and spherical diffusion from the nano-structural electrodes of the gold-coated filter membrane. The phenomenon in which charge transfer resistance, Rct, declines at high concentration ranges was found and explained by the pearl chain effect. The pearl effect could cause a false-negative at high concentrations. We modeled the pearl chain effect as an R and C, connected parallel to the low-concentration model. When users properly applied both models for analyses, this sensor could quantitatively measure cell concentrations from 400 to 400 M per milliliter with superior linearity.
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- 2023
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18. Paper-Based Loop Mediated Isothermal Amplification (LAMP) Platforms: Integrating the Versatility of Paper Microfluidics with Accuracy of Nucleic Acid Amplification Tests
- Author
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Debayan Das, Manaswini Masetty, and Aashish Priye
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LAMP ,RT-LAMP ,paper-based diagnostics ,point-of-care diagnostics ,Biochemistry ,QD415-436 - Abstract
Paper-based diagnostics offer a promising alternative to traditional diagnostic methods for point-of-care use due to their low cost, ease of use, portability, rapid results, versatility, and low environmental impact. While paper-based serology tests in the form of lateral flow assays can provide rapid test results for past pathogen exposure, they currently lack the accuracy and sensitivity offered by molecular diagnostic tests such as the polymerase chain reaction (PCR). Loop-mediated isothermal amplification (LAMP)—an isothermal nucleic acid amplification test (NAAT)—provides PCR-like performance while simultaneously reducing the instrumentation and assay complexity associated with PCR. In this review, we discuss a newly emerging class of paper-based LAMP platforms that integrates the versatility of paper microfluidics with the accuracy of NAATs. Since its first adoption in 2015, we have discussed all paper-based LAMP platforms in terms of the paper substrates, reagent incorporation techniques, paper platform design, heating hardware, detection methods, and sensitivity and specificity of paper-based LAMP assays. We conclude by identifying the current challenges and future prospects of paper-based NAATs.
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- 2023
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19. Iron Determination in Natural Waters Using a Synthesised 3-Hydroxy-4-Pyridione Ligand in a Newly Developed Microfluidic Paper-Based Device
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Juliana I. S. Aguiar, Susana O. Ribeiro, Andreia Leite, Maria Rangel, António O. S. S. Rangel, and Raquel B. R. Mesquita
- Subjects
iron quantification sensor ,microfluidic paper-based analytical device ,3-hydroxy-4-pyridinone ligand ,natural waters ,in situ analysis ,Biochemistry ,QD415-436 - Abstract
This work describes the development of an iron sensor based on a microfluidic paper-based technique, to attain iron quantification in natural waters. A new water-soluble naphthalene-3-hydroxy-4-pyridione ligand was used as a colour reagent, as it formed an orange complex with iron. As a newly described ligand, several chemical and physical parameters, namely, the sample and reagent volumes and reagent concentrations, were studied related to the formation of the coloured complex. The microfluidic paper-based analytical device (μPAD) assembly, namely, the use of different types of filter paper and different numbers of layers, was developed to obtain the best performance. Under the optimal conditions, a linear correlation was obtained in the range of 0.25–2.00 mg/L of iron, with a minimum detectable value of 0.07 mg/L. The proposed μPAD method was validated by an analysis of the certified samples and by a comparison of the tested water samples with the inductively coupled plasma (ICP) results (RE < 10%). Then, the μPAD device was successfully applied to the determination of iron in tap water, well water, river water, and seawater, with no need for any prior sample pre-treatment; recovery studies were also performed (average = 100.3% with RSD = 4.2%).
- Published
- 2023
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20. A Paper-Chip-Based Phage Biosensor Combined with a Smartphone Platform for the Quick and On-Site Analysis of E. coli O157:H7 in Foods
- Author
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Chaiyong Wu, Dengfeng Li, Qianli Jiang, and Ning Gan
- Subjects
POCT assay ,paper-chip-based phage biosensor ,smartphone ,E. coli O157:H7 ,foods ,Biochemistry ,QD415-436 - Abstract
The rapid and specific point-of-care (POC) analysis of virulent pathogenic strains plays a key role in ensuring food quality and safety. In this work, a paper-based fluorescent phage biosensor was developed for the detection of the virulent E. coli O157:H7 strain (as the mode of virulent pathogens) in food samples. Firstly, phages that can specifically combine with E. coli O157:H7 (E. coli) were stained with SYTO-13 dye to prepare a novel fluorescent probe (phage@SYTO). Simultaneously, a micro-porous membrane filter with a pore size of 0.45 μm was employed as a paper chip so as to retain the E. coli-phage@SYTO complex (>1.2 μm) on its surface. The phage@SYTO (200 nm in size) was able to pass through the pores of the chip, and the complex could be retained on the paper chip using the free phage@SYTO probes. The E. coli-phage@SYTO could emit a visual fluorescent signal (excited at 365 nm; emitted at 520 nm) onto the chip, which could be detected by a smartphone to reflect the concentration of E. coli. Under optimized conditions, the detection limit was as low as 50 CFU/mL (S/N = 3) and exhibited a wide linear range from 102 to 106 CFU/mL. The sensor has potential application value for the quick and specific POCT detection of virulent E. coli in foods.
- Published
- 2023
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21. Utilization of bio-polymeric additives for a sustainable production strategy in pulp and paper manufacturing: A comprehensive review
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Soumya Basu, Shuank Malik, Gyanesh Joshi, P.K. Gupta, and Vikas Rana
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Cellulose and derivatives ,Hemicelluloses ,Starch and derivatives ,Bio-polymeric additive ,Pulp and paper manufacturing ,Paper industries ,Biochemistry ,QD415-436 - Abstract
Renewable and bio-based materials have gained great interest on an industrial scale owing to environmental issues. Paper industries also are constantly exploring bio-resources for intrinsic chemico-physical property enhancement of paper and paper products. These bio-resources will potentially increase their cyclability besides making paper compatible beyond traditional uses. Mechanical beating or use of chemical additives or the combination of these methods are widely used to improve critical paper characteristics such as strength, surface smoothness, density, brightness, filler retention, water and grease resistivity etc. These chemical additives as mill effluents are hazardous and have detrimental effect on environment. So, to move ahead of traditional practices, the present review discusses about the production and utility of abundantly available renewable bio-polymers and their products such as starch, cellulose, plant-based proteins, microbial biopolymers, animal-based biopolymers, and natural gums etc. They represent ample prospect in terms of research and development on their functionality and industrial applications.
- Published
- 2021
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22. Fabrication of cellulose nanocrystal (CNC) from waste paper for developing antifouling and high-performance polyvinylidene fluoride (PVDF) membrane for water purification
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Pankaj Boruah, Raghvendra Gupta, and Vimal Katiyar
- Subjects
Cellulose nanocrystal ,Polyvinylidene fluoride ,Hydrophilic ,Antifouling ability ,Biochemistry ,QD415-436 - Abstract
Waste papers are used as a source of raw material to fabricate cellulose nanocrystals (CNCs), a highly valued product with a high degree of crystallinity. Rod-shaped CNCs with an average diameter of 53 ± 9 nm and an average length of 234 ± 42 nm were obtained with a crystallinity of around 78%. Polyvinylidene fluoride (PVDF) thin composite membrane was developed by adding CNCs into the PVDF matrix in different amounts (0, 0.5, 1, 1.5, 2, 3 wt%). Porous finger-like structures in the membrane increased with an increase in CNC content. The FTIR measurement and high-resolution FESEM image of the membranes verified the presence of CNCs in the composite membranes. 48% high pure water flux (PWF) was obtained for PVDF/CNC as compared to pristine PVDF membrane with the addition of 3% CNCs at a pressure of 1 kg−1cm−2. Water contact angle (WCA) also decreased from 85° to 69° with increasing the wt% of CNCs in the dope solution, which signifies improved hydrophilicity. Further, the PVDF/CNCs membrane showed a high bovine serum albumin (BSA) rejection of 93% and a flux recovery ratio (FRR) of 76.76 %, whereas the pristine PVDF membrane showed BSA rejection of 70.86% and a FRR of 40.82 %, respectively.
- Published
- 2023
- Full Text
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23. Preparation of hydrophobic transparent paper via using polydimethylsiloxane as transparent agent
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Feixiang Guan, Zhaoping Song, Furong Xin, Huili Wang, Dehai Yu, Guodong Li, and Wenxia Liu
- Subjects
Transparent paper ,Cellulose fiber paper ,Hydrophobicity ,Tetraethyl orthosilicate (TEOS) ,Polydimethylsiloxane ,Biochemistry ,QD415-436 - Abstract
Transparent paper with good hydrophobicity and flexibility was expected to act as an alternative substrate in fabrication of flexible electronics. However, conventional paper made of cellulose fibers was opaque and hydrophilic without undergoing special processing. Herein, cellulose fiber paper was treated by impregnating with hydrolyzed tetraethyl orthosilicate (TEOS) followed by coating with hydrophobic polydimethylsiloxane (PDMS) to prepare hydrophobic transparent paper. The results showed that silica nanoparticles produced by the TEOS hydrolysis improved the paper transparency to some extent, increased the paper thermal stability, but still remained the hydrophilicity of paper. After the paper was further coated with the PDMS and the PDMS was consolidated, the paper became clearly transparent and hydrophobic. The processed paper had a transmittance of more than 90% at 550 nm. The water contact angle of the paper reached about 110°. This work provided a new approach for the fabrication of hydrophobic transparent paper with conventional cellulose fiber paper.
- Published
- 2020
- Full Text
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24. Paper-Based Analytical Device for One-Step Detection of Bisphenol-A Using Functionalized Chitosan
- Author
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Abdelhafid Karrat and Aziz Amine
- Subjects
chitosan ,smartphone ,paper-based analytical devices ,one-step detection ,bisphenol-A ,Biochemistry ,QD415-436 - Abstract
Bisphenol-A (BPA) is defined as one of the endocrine disrupting compounds. The accurate and inexpensive colorimetric paper-based analytical devices (PADs) are of crucial importance for BPA analysis. In this context, we developed for the first time a new PAD modified with chitosan and sulfamethoxazole (Chitosan-PAD) for the visual detection of BPA in water. The PAD was characterized by Fourier-transform infrared spectroscopy, which confirmed its modification by the functionalized chitosan. A yellow coloration was developed when a small volume of BPA was added to the Chitosan-PAD, allowing for visual and smartphone detection. This new strategy is based on a specific combination of BPA with chitosan and sulfamethoxazole that provides a hight selectivity to the Chitosan-PAD. The proposed PAD was successfully employed in combination with a pre-concentration step for the detection of 0.01 µg mL−1 of PBA with the naked eye using a 10-fold preconcentration factor. The PAD was effectively applied for BPA quantification in water samples with good recoveries. The developed PAD provides a green and cost-effective strategy for the on-site and one-step detection of BPA in water samples.
- Published
- 2022
- Full Text
- View/download PDF
25. Evaluating process of auto-hydrolysis prior to kraft pulping on production of chemical pulp for end used paper-grade products
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Wenchao Jia, Miaofang Zhou, Chenfeng Yang, He Zhang, Meihong Niu, and Haiqiang Shi
- Subjects
Auto-hydrolysis ,Kraft pulping ,Pulping performance ,Fiber morphology ,Black liquor ,Biochemistry ,QD415-436 - Abstract
The objective of this work is to systematically evaluate the performance of the hydrolysis-based kraft pulping process and associated pulp and black liquor characteristics. Acacia wood chips were auto-hydrolyzed under various severities, then the hydrolyzed wood chips were kraft pulping. The results indicated that the yield of pulp significantly dropped with intensifying the auto-hydrolysis severity. Meanwhile, the removal rate of pentosan reached 98.6% in the screened pulp at the P-factor of 1 000. The fiber length, fines and fiber crimp of the screened pulp were not affected by the auto-hydrolysis treatment. Auto-hydrolyzed pulps deteriorated fibrillation and beating response of the pulp in a refining process. However, fiber length and fines changed obviously after beating treatment. After auto-hydrolysis, the tensile index of the paper matrices decreased, some particle substances were found on the surface of the pulp fiber, and the solid and organic content of the black liquor were improved.
- Published
- 2022
- Full Text
- View/download PDF
26. Early responses to Avery et al.'s paper on DNA as hereditary material
- Author
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DEICHMANN, UTE
- Published
- 2004
- Full Text
- View/download PDF
27. An Economical and Portable Paper-Based Colorimetric Sensor for the Determination of Hydrogen Peroxide-Related Biomarkers
- Author
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Wei-Yi Zhang, Hao Zhang, and Feng-Qing Yang
- Subjects
paper-based analytical device ,colorimetric sensor ,point-of-care testing ,iodide ,glucose oxidase ,Biochemistry ,QD415-436 - Abstract
In this study, a paper-based sensor was developed for the detection of hydrogen-peroxide-related biomarkers, with glucose oxidase catalyzing as an example. Potassium iodide can catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine in the presence of hydrogen peroxide to colorize the paper-based biosensor detection area, which was imaged by a scanner, and the color intensity was analyzed by the Adobe Photoshop. Under the optimal conditions, the color intensity shows a good linear relationship with hydrogen peroxide and glucose concentrations in the ranges of 0.1–5.0 mM and 0.5–6.0 mM, respectively. The detection limit of hydrogen peroxide is 0.03 mM and the limit of quantification of glucose is 0.5 mM. Besides, the method was employed in measuring glucose concentration in fruit samples, and the spiked recoveries are in the range of 95.4–106.1%. This method is cost-effective, environmentally friendly, and easy to be operated, which is expected to realize the point-of-care testing of more hydrogen-peroxide-related biomarkers.
- Published
- 2022
- Full Text
- View/download PDF
28. Development of a Paper-Based Analytical Method for the Selective Colorimetric Determination of Bismuth in Water Samples
- Author
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Panagiotis A. Bizirtsakis, Maria Tarara, Apostolia Tsiasioti, Paraskevas D. Tzanavaras, and George Z. Tsogas
- Subjects
paper-based analytical devices ,colorimetric determination ,bismuth ,methyl thymol blue ,water samples ,Biochemistry ,QD415-436 - Abstract
A novel, direct and simple colorimetric method employing μicroanalytical paper-based devices (μ-PADs) for the selective determination of bismuth is described. The suggested method exploits the colorimetric variation of bismuth after its rapid reaction with methyl thymol blue (MTB) in an acidic medium (pH ranging between 0.7 and 3.0), modified with nitric acid, on the surface of a paper device at room temperature. The devices are low cost, composed of chromatographic paper and wax barriers and the analytical protocol is easily applicable with minimal technical expertise and without the need for experimental apparatus. The user must add a test sample and read the color intensity of the colored Bi(III)–MTB complex formed at the sensing area using a simple imaging device such as a flatbed scanner. Various chemical variables, such as HNO3 and MTB concentration, reaction time, ionic strength, detection zone size and photo-capture detector are optimized. A study of interfering ions such as K+, Na+, Ca2+, Mg2+, Cl−, SO42− and HCO3− was also conducted. The stability of the paper devices is also studied in different maintenance conditions with particularly satisfactory results, rendering the method suitable for field analysis. The detection limits are as low as 3.0 mg L−1 with very satisfactory precision, ranging from 4.0% (intra-day) to 5.5% (inter-day). Natural water samples are successfully analyzed, and bismuth percentage recoveries were calculated in the range of 82.8 to 115.4%.
- Published
- 2022
- Full Text
- View/download PDF
29. Position Paper Progress in the development of biomimetic engineered human tissues
- Author
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Umber Cheema
- Subjects
Biochemistry ,QD415-436 - Abstract
Tissue engineering (TE) is the multi-disciplinary approach to building 3D human tissue equivalents in the laboratory. The advancement of medical sciences and allied scientific disciplines have aspired to engineer human tissues for three decades. To date there is limited use of TE tissues/organs as replacement body parts in humans. This position paper outlines advances in engineering of specific tissues and organs with tissue-specific challenges. This paper outlines the technologies most successful for engineering tissues and key areas of advancement.
- Published
- 2023
- Full Text
- View/download PDF
30. Efficient Transfer of Large DNA Fragments from Agarose Gels to Diazobenzyloxymethyl-Paper and Rapid Hybridization by using Dextran Sulfate
- Author
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Wahl, Geoffrey M., Stern, Michael, and Stark, George R.
- Published
- 1979
31. Consolation for the Scientist: Sometimes It is Hard to Publish Papers That are Later Highly-Cited
- Author
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Campanario, Juan Miguel
- Published
- 1993
32. Highly Cited Soviet Papers: An Exploratory Investigation
- Author
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Narin, Francis, Frame, J. Davidson, and Carpenter, Mark P.
- Published
- 1983
33. The Problem of Junior-Authored Papers in Constructing Citation Counts
- Author
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Long, J. Scott, McGinnis, Robert, and Allison, Paul D.
- Published
- 1980
34. A Study of the Removal and Prevention of Fungal Stains on Paper
- Author
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Szczepanowska, Hanna and Lovett, Charles M.
- Published
- 1992
- Full Text
- View/download PDF
35. Wax-Printed Fluidic Controls for Delaying and Accelerating Fluid Transport on Paper-Based Analytical Devices
- Author
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Maria Tarara, Dimosthenis L. Giokas, and George Z. Tsogas
- Subjects
paper-based analytical devices ,wax-printed barriers ,fluid control ,delay and acceleration of fluid flow ,enzymatic assay of glucose ,Biochemistry ,QD415-436 - Abstract
In this work, we explore a new method for controlling fluid transport rate on paper-based analytical devices that enables both the delay and the acceleration of fluid flow. The delays were incorporated by wax printing linear patterns of variable width within the flow channel and melted to penetrate the paper. In this manner, the surface tension of the fluid decreases while its contact angle increases, causing a pressure drop along the fluid path that reduces capillary flow. The acceleration of flow was accomplished by overlaying hydrophobic stripes (prepared by wax printing and melting the wax) on the hydrophilic path (top or top–bottom). In this manner, the fluid was repelled from two dimensions (vertical and applicate), increasing the flow rate. The combination of these methods on the same devices could adjust wicking time in intermediate time internals. The method enabled a wide timing of fluid transport, accomplishing a change in wicking times that extended from −41% to +259% compared to open paper channels. As a proof of concept, an enzymatic assay of glucose was used to demonstrate the utility of these fluid control methods in kinetic methods of analysis.
- Published
- 2022
- Full Text
- View/download PDF
36. A Paper-Based Multicolor Colorimetric Aptasensor for the Visual Determination of Multiple Sulfonamides Based on Aptamer-Functionalized Magnetic Beads and NADH–Ascorbic Acid-Mediated Gold Nanobipyramids
- Author
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Meiling Ping, Wenchao Lv, Chen Yang, Qian Chen, Zongwen Wang, and Fengfu Fu
- Subjects
aptasensor ,antibiotics residue ,seafood ,sulfonamides ,visual detection ,Biochemistry ,QD415-436 - Abstract
It is crucial that simple and high-throughput methods for determining multiple, or groups of, sulfonamides (SAs) be developed since they are widely used in animal husbandry and aquaculture. We developed a paper-based multicolor colorimetric aptasensor to detect 3 SAs: sulfaquinoxaline (SQ), sulfamethoxypyridazine (SMP) and sulfamethoxydiazine (SMD). Using a broad-specificity aptamer as a bioreceptor, we reduced the growth of nicotinamide adenine dinucleotide I (NADH)–ascorbic acid (AA)-mediated gold nanobipyramids (AuNBPs) to generate a multicolor signal. We also used a paper-based analytical device (PAD) system to deposit AuNBPs for a sensitive color signal read out. The aptasensor can detect more color changes corresponding to the concentrations of SQ, SMP and SMD and has higher sensitivity, better specificity and stability. It can also be used to determine SQ, SMP and SDM individually, or collectively, or any two together with a visual detection limit of 0.3–1.0 µM, a spectrometry quantification limit (LOQ) of 0.3–0.5 µM and a spectrometry detection limits (LOD) of 0.09–0.15 µM. The aptasensor was successfully used to determine SQ, SMP and SDM in fish muscle with a recovery of 89–94% and a RSD n = 5) < 8%, making it a promising method for the rapid screening of total SQ, SMP and SDM residue in seafood.
- Published
- 2023
- Full Text
- View/download PDF
37. Disposable Microfluidic Paper-Based Device for On-Site Quantification of Urinary Creatinine
- Author
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Maria M. P. Melo, Ana Machado, António O. S. S. Rangel, and Raquel B. R. Mesquita
- Subjects
µPAD ,creatinine determination ,urine samples ,Jaffe reaction ,real-time analysis ,Biochemistry ,QD415-436 - Abstract
In this work, a new microfluidic paper-based analytical device (µPAD) was developed for on-hand creatinine quantification in urine samples. When compared to conventional methods, this innovative paper device is more accessible and portable, it provides low-cost analysis (cost of consumables of 40 cents), and it is applicable to non-invasive biological fluids. Furthermore, the paper-based approach is used within an environmentally friendly assembly with no need for wax printing and small amounts of reagents resulting in low waste production and easy disposal by incineration. Its assembly method includes cutting paper discs arranged into several reading units within a plastic pouch, enabling effective creatinine quantification with accuracy based on a vertical flow approach. The method is based on the colourimetric reaction between creatinine and alkaline picric acid, where the solution colour changes from yellow to orange/red. Under optimal conditions, the developed method allowed creatinine quantification in the dynamic range of 2.20–35.0 mg/dL, with a limit of detection (LOD) of 0.66 mg/dL and a limit of quantification (LOQ) of 2.20 mg/dL. The colour intensity developed was processed in ImageJ software, based on digital image scanning, performed in 20 min (up to 4 h) after the sample insertion. The device is stable for up to one week when stored in a vacuum at 4 °C. The method was validated by comparing the results with a batch-wise procedure, where there were no statistically significant differences between both methods.
- Published
- 2023
- Full Text
- View/download PDF
38. In Situ Detection of Hydrogen Sulfide in 3D-Cultured, Live Prostate Cancer Cells Using a Paper-Integrated Analytical Device
- Author
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Jae-Hyung Kim, Young-Ju Lee, Yong-Jin Ahn, Minyoung Kim, and Gi-Ja Lee
- Subjects
paper ,three-dimensional cell culture ,hydrogen sulfide ,live cancer cells ,colorimetric sensing paper ,paper-integrated analytical device ,Biochemistry ,QD415-436 - Abstract
In this study, a paper-integrated analytical device that combined a paper-based colorimetric assay with a paper-based cell culture platform was developed for the in situ detection of hydrogen sulfide (H2S) in three-dimensional (3D)-cultured, live prostate cancer cells. Two kinds of paper substrates were fabricated using a simple wax-printing methodology to form the cell culture and detection zones, respectively. LNCaP cells were seeded directly on the paper substrate and grown in the paper-integrated analytical device. The cell viability and H2S production of LNCaP cells were assessed using a simple water-soluble tetrazolium salt colorimetric assay and H2S-sensing paper, respectively. The H2S-sensing paper showed good sensitivity (sensitivity: 6.12 blue channel intensity/μM H2S, R2 = 0.994) and a limit of quantification of 1.08 μM. As a result, we successfully measured changes in endogenous H2S production in 3D-cultured, live LNCaP cells within the paper-integrated analytical device while varying the duration of incubation and substrate concentration (L-cysteine). This paper-integrated analytical device can provide a simple and effective method to investigate H2S signaling pathways and drug screening in a 3D culture model.
- Published
- 2022
- Full Text
- View/download PDF
39. Commemorating the 1913 Michaelis-Menten paper Die Kinetik der Invertinwirkung: three perspectives.
- Author
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Deichmann U, Schuster S, Mazat JP, and Cornish-Bowden A
- Subjects
- Algorithms, Berlin, History, 19th Century, History, 20th Century, Japan, Kinetics, New York, beta-Fructofuranosidase chemistry, Biochemistry history
- Abstract
Methods and equations for analysing the kinetics of enzyme-catalysed reactions were developed at the beginning of the 20th century in two centres in particular; in Paris, by Victor Henri, and, in Berlin, by Leonor Michaelis and Maud Menten. Henri made a detailed analysis of the work in this area that had preceded him, and arrived at a correct equation for the initial rate of reaction. However, his approach was open to the important objection that he took no account of the hydrogen-ion concentration (a subject largely undeveloped in his time). In addition, although he wrote down an expression for the initial rate of reaction and described the hyperbolic form of its dependence on the substrate concentration, he did not appreciate the great advantages that would come from analysis in terms of initial rates rather than time courses. Michaelis and Menten not only placed Henri's analysis on a firm experimental foundation, but also defined the experimental protocol that remains standard today. Here, we review this development, and discuss other scientific contributions of these individuals. The three parts have different authors, as indicated, and do not necessarily agree on all details, in particular about the relative importance of the contributions of Michaelis and Menten on the one hand and of Henri on the other. Rather than force the review into an unrealistic consensus, we consider it appropriate to leave the disagreements visible., (© 2013 FEBS.)
- Published
- 2014
- Full Text
- View/download PDF
40. Teaching Aldosterone Regulation and Basic Scientific Principles Using a Classic Paper by Dr. James O. Davis and Colleagues
- Author
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Hanke, Craig J. and Bauer-Dantoin, Angela C.
- Abstract
Classroom discussion of scientific articles can be an effective means of teaching scientific principles and methodology to both undergraduate and graduate science students. The availability of classic papers from the American Physiological Society Legacy Project has made it possible to access articles dating back to the early portions of the 20th century. In this article, we discuss a classic paper from the laboratory of Dr. James O. Davis on the regulation of aldosterone synthesis from the adrenal zona glomerulosa cell. Dr. Davis has conducted much of the seminal research investigating the renin-angiotensin system and the regulation of aldosterone release by angiotensin II. In addition to a characterization of the effects of ACTH on aldosterone regulation, this study is useful for discussing the basic principles of negative feedback pathways of the hypothalamic-pituitary axis. This study also provides examples of early bioassay techniques for the detection of angiotensin II and of the importance of quantitative measurements when investigating physiological responses. Three figures and one table are reproduced from the original article along with a series of discussion questions designed to facilitate discovery learning.
- Published
- 2006
- Full Text
- View/download PDF
41. Plastic-free chitosan and cellulose binder providing dry and wet strength to paper and nonwoven
- Author
-
Maria Wennman, Mårten Hellberg, Anna J Svagan, and Mikael S Hedenqvist
- Subjects
Nonwoven ,Binder ,Polyelectrolyte complex ,Chitosan ,Biobased ,Biochemistry ,QD415-436 - Abstract
Chemically-bonded nonwoven is commonly used in single-use products, and are often composed of cellulose fibers with a fossil-based binder. To reduce the amount of plastic littering, we investigated a biobased and biodegradable binder consisting of polyelectrolyte complexes based on chitosan, carboxymethyl cellulose and citric acid. The binder significantly improved the mechanical properties of two different types of cellulosic fiber systems in both dry and wet states. The quality of the water used in the binder had a significant impact on the mechanical properties, especially in the dry state, indicating a beneficial effect by the presence of cations. It was shown that covalent bonds were formed during the low temperature drying, and that the amount of bonds increased with a high temperature curing. Electron microscopy and tensile data indicated that the binder acted as a joint between the fiber/fiber parts. The presented results enable a sustainable solution for the current plastic-based nonwoven industry.
- Published
- 2022
- Full Text
- View/download PDF
42. Teaching the Modes of Ca[superscript 2+] Transport between the Plasma Membrane and Endoplasmic Reticulum Using a Classic Paper by Kwan et al.
- Author
-
Liang, Willmann
- Abstract
This teaching article uses the report by Kwan et al., "Effects of methacholine, thapsigargin, and La[superscript 3+] on plasmalemmal and intracellular Ca[superscript 2+] transport in lacrimal acinar cells," where the effects of Ca[superscript 2+]-mobilizing agents in regulating Ca[superscript 2+] fluxes were examined under various conditions. Upper-level undergraduate and new graduate students in physiology are the target audience. Teaching and learning points are put forth in this article to illustrate 1) the characteristics of methacholine- and thapsigargin-induced Ca[superscript 2+] responses, 2) the different endoplasmic reticulum Ca[superscript 2+] stores accessible to methacholine and thapsigargin, 3) the inhibitory effects of La[superscript 3+] on Ca[superscript 2+] extrusion and Ca[superscript 2+] influx, and 4) the facilitatory role of La[superscript 3+] on endoplasmic reticulum Ca[superscript 2+] recycling. Each of the above concepts is first explained with references to the figures adapted from the original article. A list of student learning questions then follows, where the answers are found in the teaching notes for the instructors. It is the objective of this article to make both teaching and learning Ca[superscript 2+] regulation a rewarding experience for all. (Contains 5 figures.)
- Published
- 2009
- Full Text
- View/download PDF
43. A Novel Truncated DNAzyme Modified Paper Analytical Device for Point-of-Care Test of Copper Ions in Natural Waters
- Author
-
Jiayi Wu, Ming Wang, Huanhuan Hong, Jianyuan Lin, Ning Gan, and Wenchao Bi
- Subjects
paper-based device ,mobile phone ,DNAzyme ,Cu(II)-catalyzed azide-alkyne cycloaddition ,copper detection ,natural waters ,Biochemistry ,QD415-436 - Abstract
On-site determination of trace copper ions in natural waters is of great significance to environmental monitoring, and how to develop accurate and specific point-of-care test methods is one critical issue. In the study, a paper-based analytical device (PAD) being modified with a new truncated DNAzyme (CLICK-T, which was derived from a reported DNAzyme-CLICK-17) was developed for Cu ions detection. The detection mechanism was based on Cu(II)-catalyzed azide-alkyne cycloaddition (Cu(II)AAC) reaction. It can directly conduct on-site analysis of Cu(II) ions based on fluorescent signals detected using a mobile phone. In the assay, the CLICK-T was firstly modified on the PADs. Then, water samples containing Cu ions mixed with 3-azido-7-hydroxycoumarin and 3-butyn-1-ol were instantly dripped on PADs and incubated for 20 min. Finally, the PADs were excited at 365 nm and emitted fluorescence which could be analyzed on site using smart phones. The Cu(II) concentration could be quantified through RGB analysis with the aid of iPhone APP software. The limit of detection is 0.1 µM by the naked eye due to the fact that CLICK-T exhibited a good catalytic effect on Cu(II)AAC. The Cu(II) concentration could also be directly detected without using reductant, such as ascorbic acid, which is prone to be oxidized in air. This simplifies the PDA detection process improves its efficiency. The PAD is convenient for the on-site analysis of Cu ions in natural waters.
- Published
- 2022
- Full Text
- View/download PDF
44. Highly cited paper of IJBB: a report.
- Author
-
Mahesh G and Panwar Y
- Subjects
- India, Manuscripts, Medical as Topic, Biochemistry, Journal Impact Factor, Periodicals as Topic statistics & numerical data, Publishing statistics & numerical data, Spectrum Analysis
- Published
- 2013
45. Paper-Based Vapor Detection of Formaldehyde: Colorimetric Sensing with High Sensitivity
- Author
-
Chenglong Liao, Miao Zhang, Nan Gao, Qingyun Tian, Jiangfan Shi, Shuai Chen, Chuanyi Wang, and Ling Zang
- Subjects
vapor detection ,formaldehyde ,colorimetric ,paper-based sensor ,hydroxylamine ,Biochemistry ,QD415-436 - Abstract
We report on a novel colorimetric sensor system for highly sensitive detection of formaldehyde (FA) in the gas phase. The sensor is constructed with paper towel as a substrate coated with the sulfuric acid salt of hydroxylamine ((NH2OH)2·H2SO4) together with two pH indicators, bromophenol blue and thymol blue. Upon exposure to FA, the hydroxylamine will react with the absorbed FA to form a Schiff base (H2C=N-OH), thus releasing a stoichiometric amount of sulfuric acid, which in turn induces a color change of the pH indicator. Such a color change was significantly enriched by incorporating two pH indicators in the system. With the optimized molar ratio of the two pH indicators, the color change (from brown to yellow, and to red) could become so dramatic as to be visible to the eye depending on the concentration of FA. In particular, under 80 ppb of FA (the air quality threshold set by WHO) the color of the sensor substrate changes from brown to yellow, which can even be envisioned clearly by the naked eyes. By using a color reader, the observed color change can be measured quantitatively as a function of the vapor concentration of FA, which produces a linear relationship as fitted with the data points. This helps estimate the limit of detection (LOD), to be 10 ppb under an exposure time of 10 min, which is much lower than the air quality threshold set by WHO. The reported sensor also demonstrates high selectivity towards FA with no color change observed when exposed to other common chemicals, including solvents and volatile organic compounds. With its high sensitivity and selectivity, the proposed paper-based colorimetric sensor thus developed can potentially be employed as a low-cost and disposable detection kit that may find broad application in detecting FA in indoor air and many other environments.
- Published
- 2021
- Full Text
- View/download PDF
46. Fabrication of an All-Solid-State Ammonium Paper Electrode Using a Graphite-Polyvinyl Butyral Transducer Layer
- Author
-
Irena Ivanišević, Stjepan Milardović, Antonia Ressler, and Petar Kassal
- Subjects
ammonium ,solid contact ion-selective electrode ,paper-based sensor ,membrane ,potentiometric sensor ,Biochemistry ,QD415-436 - Abstract
A planar solid-state ammonium-selective electrode, employing a composite mediator layer of graphite particles embedded in a polyvinyl butyral matrix on top of an inkjet-printed silver electrode, is presented in this paper. The effect of graphite powder mass fraction on the magnitude of the potentiometric response of the sensor was systematically verified using a batch-mode and a flow injection measurement setup. Under steady-state conditions, the paper electrode provided a Nernstian response of 57.30 mV/pNH4 over the concentration range of 10−5 M to 10−1 M with a detection limit of 4.8 × 10−6 M, while the analytical performance of the array in flow mode showed a narrower linear range (10−4 M to 10−1 M; 60.91 mV/pNH4 slope) with a LOD value of 5.6 × 10−5 M. The experimental results indicate that the prepared electrode exhibited high stability and fast response to different molar concentrations of ammonium chloride solutions. The pH-response of the paper NH4-ISE was also investigated, and the sensor remained stable in the pH range of 2.5–8.5. The potentiometric sensor presented here is simple, lightweight and inexpensive, with a potential application for in-situ analysis of environmental water samples.
- Published
- 2021
- Full Text
- View/download PDF
47. Paper-Based Device for Sweat Chloride Testing Based on the Photochemical Response of Silver Halide Nanocrystals
- Author
-
Tatiana G. Choleva, Christina Matiaki, Afroditi Sfakianaki, Athanasios G. Vlessidis, and Dimosthenis L. Giokas
- Subjects
sweat testing ,cystic fibrosis ,paper-based devices ,silver halides ,photoreduction ,point-of-care diagnostics ,Biochemistry ,QD415-436 - Abstract
A new method for the determination of chloride anions in sweat is described. The novelty of the method relies on the different photochemical response of silver ions and silver chloride crystals when exposed to UV light. Silver ions undergo an intense colorimetric transition from colorless to dark grey-brown due to the formation of nanosized Ag while AgCl exhibits a less intense color change from white to slightly grey. The analytical signal is obtained as mean grey value of color intensity on the paper surface and is expressed as the absolute difference between the signal of the blank (i.e., in absence of chloride) and the sample (i.e., in the presence of chloride). The method is simple to perform (addition of sample, incubation in the absence of light, irradiation, and offline measurement in a flatbed scanner), does not require any special signal processing steps (the color intensity is directly measured from a constant window on the paper surface without any imager processing) and is performed with minimum sample volume (2 μL). The method operates within a large chloride concentration range (10–140 mM) with good detection limits (2.7 mM chloride), satisfactory recoveries (95.2–108.7%), and reproducibility (
- Published
- 2021
- Full Text
- View/download PDF
48. Development of a High-Throughput Low-Cost Approach for Fabricating Fully Drawn Paper-Based Analytical Devices Using Commercial Writing Tools
- Author
-
Varvara Pagkali, Eleftheria Stavra, Dionysios Soulis, and Anastasios Economou
- Subjects
paper-based devices ,pen-on-paper ,plotting ,optical sensing ,electrochemical sensing ,marker pens ,Biochemistry ,QD415-436 - Abstract
This work reports the development and optimization of a rapid and low-cost pen-on-paper plotting approach for the fabrication of paper-based analytical devices (PADs) using commercial writing stationery. The desired fluidic patterns were drawn on the paper substrate with commercial marker pens using an inexpensive computer-controlled x–y plotter. For the fabrication of electrochemical PADs, electrodes were further deposited on the devices using a second x–y plotting step with commercial writing pencils. The effect of the fabrication parameters (type of paper, type of marker pen, type of pencil, plotting speed, number of passes, single- vs. double-sided plotting), the chemical resistance of the plotted devices to different solvents and the structural rigidity to multiple loading cycles were assessed. The analytical utility of these devices is demonstrated through application in optical sensing of total phenols using reflectance calorimetry and in electrochemical sensing of paracetamol and ascorbic acid. The proposed manufacturing approach is simple, low cost, flexible, rapid and fit-for-purpose and enables the fabrication of sub-“one-dollar” PADs with satisfactory mechanical and chemical resistance and good analytical performance.
- Published
- 2021
- Full Text
- View/download PDF
49. Retrieving structural information from scattering and attenuation data of transparent wood and (Nano)paper
- Author
-
Yoshiharu Nishiyama
- Subjects
Light scattering ,Transparent wood ,Nanocellulose ,Biochemistry ,QD415-436 - Abstract
Over the last 15 years, significant number of reports on transparent paper and transparent wood appeared in the literature. The light scattering data or transmission data are often given to describe the optical performance of the material. In addition, the data also contains structural information that can be further analyzed based on scattering theory. Some of the data are re-analyzed herein from structural analysis point of view related to the scattering phenomena. Quantitative analysis on the wavelength dependent optical density of nanopaper suggested that the scatterers are not isolated voids or microfibrils but rather large submicrometric and structural domains. Angular dependence of transparent wood scattering suggests the scattering units of a few micrometers such as cell wall are at the origin of high haze.
- Published
- 2021
- Full Text
- View/download PDF
50. Secondary School Students' Perception of Biochemistry Concepts by Using Word Association Test
- Author
-
Roncevic, Tamara N., Horvat, Saša A., Rodic, Dušica D., and Bogdanovic, Ivana Z.
- Abstract
A word association test was used to determine knowledge structures on biochemistry concepts of secondary school chemistry students, aged between 18-19 years. The basic biochemistry concepts related to the topic of Carbohydrates that take place in the International Baccalaureate Diploma Programme curriculum were determined as stimulus words: "Monosaccharides", "Glucose", "Cellular respiration", "Fructose", "Disaccharides", "Glycosidic bonds", "Polysaccharides", "Starch". Students were required to provide response words for each of the eight stimulus words within the pre-determined period of time. Analysis of data was done in order to find the stimulus words with the highest number of associations in students' knowledge structures and to calculate the relatedness coefficient between the stimulus words, in order to construct the relatedness networks that should model the students' knowledge structures. The results showed that students managed to relate most of the stimulus words with strong or medium strength links, however, "Cellular respiration" remained unconnected to other stimulus words in the students' knowledge structures. [For the full proceedings, see ED629086.]
- Published
- 2023
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