Eucalyptus Biochar as a Sustainable Nanomaterial for Electrochemical Sensors

Carbonaceous-based nanomaterials (C-NMs) are the pillar of myriad sensing and catalytic electrochemical applications. In this field, the search for environmentally sustainable C-NMs from renewable sources became a duty in the development of nano-sensors. Herein, water-soluble carbon nanofibers (CF) were produced from eucalyptus scraps-based biochar (BH) through an ultrasound treatment, assisted by sodium cholate used as a stabilizing agent. Noteworthy, thanks to the use of the bio-stabilizing agent, the nanofibers were dispersed in water avoiding the use of organic solvents. The BH-CF was investigated as sensing material onto commercial screen-printed electrodes via drop-casting (BH-SPE) and as thin-film fully integrated into a lab-made flexible electrode. The thin film was produced via BH-CF vacuum filtration followed by the film transferring to a thermo-adhesive plastic substrate through thermal lamination. This approach gave rise to a conductive BH-CF film (BH-Film) easily embodied in a lab-made electrode produced with office-grade instrumentation (i.e., craft-cutter machine, thermal laminator) and materials (i.e., laminating pouches, stencil). The BH-CF amount was optimized and the resulting film morphologically characterized, then, the electrochemical performances were studied. The BH-CF electrochemical features were investigated towards a broad range of analytes containing phenol moieties, discrimination between orto- and mono-phenolic structures were achieved for all the studied compounds. As proof of applicability, the BH-CF-based sensors were challenged for simultaneous determination of mono-phenols and ortho-diphenols in olive oil extracts. LODs ≤ 0.5 μM and ≤ 3.8 μM were obtained for hydroxytyrosol (o-diphenol reference standard) and Tyrosol (m-phenols reference standard), respectively. Moreover, a high inter-sensors precision (RSD calibration-slopes ≤ 7%, n = 3) and quantitative recoveries in sample analysis (recoveries 91–111%, RSD ≤ 6%) were obtained. Here, a solvent-free strategy to obtain water-soluble BH-CF was proposed, and their usability to sensor fabrication and modification proved. This work demonstrated as cost-effective and sustainable renewable sources, rationally used, can lead to obtain useful nanomaterials.

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Thin Film Solid Oxide Fuel Cells Deposited by Spray Pyrolysis

Journal of Fuel Cell Science and Technology ◽

10.1115/1.3176401 ◽

2010 ◽

Vol 7 (2) ◽

Cited By ~ 18

Author(s):

Yongsong Xie ◽

Roberto Neagu ◽

Ching-Shiung Hsu ◽

Xinge Zhang ◽

Cyrille Decès-Petit ◽

...

Keyword(s):

Thin Film ◽

Fuel Cells ◽

Solid Oxide Fuel Cells ◽

Spray Pyrolysis ◽

Spray Deposition ◽

Cost Effective ◽

Solid Oxide ◽

Electrochemical Performances ◽

Oxide Fuel ◽

Deposition Processes

Two techniques of spray pyrolysis, namely, electrostatic and pneumatic spray deposition, were used to deposit samaria-doped ceria (SDC) electrolyte and lanthanum strontium cobalt ferrite (LSCF) cathode on cermet or metal supported anodes for solid oxide fuel cells (SOFCs) operated at reduced temperature. The deposition processes, the properties of the deposited films, and the electrochemical performances of the fabricated cells are reported in this paper. The deposited SDC electrolytes were dense and gas-tight, and had good adhesion to the underlying anodes. The deposited LSCF cathode had a preferred morphology to facilitate the transport of oxygen gas and effective contact with the electrolyte. Button cell testing indicated that the SOFCs with electrolyte or cathode deposited by spray pyrolysis had good electrochemical performance. This study demonstrated that spray pyrolysis is a cost-effective process for fabricating thin film SOFCs, especially metal supported SOFCs.

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A cost‐effective fluorination method for enhancing the performance of metal oxide thin‐film transistors

Journal of the Society for Information Display ◽

10.1002/jsid.1013 ◽

2021 ◽

Author(s):

Sunbin Deng ◽

Shou‐Cheng Dong ◽

Rongsheng Chen ◽

Wei Zhong ◽

Guijun Li ◽

...

Keyword(s):

Thin Film ◽

Metal Oxide ◽

Thin Film Transistors ◽

Cost Effective ◽

Oxide Thin Film ◽

Metal Oxide Thin Film

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Titanium Nitride Thin Film Based Low-Redox-Interference Potentiometric pH Sensing Electrodes

Sensors ◽

10.3390/s21010042 ◽

2020 ◽

Vol 21 (1) ◽

pp. 42

Author(s):

Shimrith Paul Shylendra ◽

Wade Lonsdale ◽

Magdalena Wajrak ◽

Mohammad Nur-E-Alam ◽

Kamal Alameh

Keyword(s):

Thin Film ◽

Titanium Nitride ◽

Orange Juice ◽

Ph Sensor ◽

Reference Electrode ◽

Cost Effective ◽

Ph Sensing ◽

Ph Sensors ◽

Potential Shift ◽

Double Junction

In this work, a solid-state potentiometric pH sensor is designed by incorporating a thin film of Radio Frequency Magnetron Sputtered (RFMS) Titanium Nitride (TiN) working electrode and a commercial Ag|AgCl|KCl double junction reference electrode. The sensor shows a linear pH slope of −59.1 mV/pH, R2 = 0.9997, a hysteresis as low as 1.2 mV, and drift below 3.9 mV/h. In addition, the redox interference performance of TiN electrodes is compared with that of Iridium Oxide (IrO2) counterparts. Experimental results show −32 mV potential shift (E0 value) in 1 mM ascorbic acid (reducing agent) for TiN electrodes, and this is significantly lower than the −114 mV potential shift of IrO2 electrodes with sub-Nernstian sensitivity. These results are most encouraging and pave the way towards the development of miniaturized, cost-effective, and robust pH sensors for difficult matrices, such as wine and fresh orange juice.

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Nanoformulation and Evaluation of Oral Berberine-Loaded Liposomes

Molecules ◽

10.3390/molecules26092591 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2591

Author(s):

Thuan Thi Duong ◽

Antti Isomäki ◽

Urve Paaver ◽

Ivo Laidmäe ◽

Arvo Tõnisoo ◽

...

Keyword(s):

Thin Film ◽

Drug Release ◽

Size Distribution ◽

Water Soluble ◽

Release Behavior ◽

Uniform Size ◽

Ethanol Injection ◽

Drug Release Behavior ◽

Poorly Water Soluble

Berberine (BBR) is a poorly water-soluble quaternary isoquinoline alkaloid of plant origin with potential uses in the drug therapy of hypercholesterolemia. To tackle the limitations associated with the oral therapeutic use of BBR (such as a first-pass metabolism and poor absorption), BBR-loaded liposomes were fabricated by ethanol-injection and thin-film hydration methods. The size and size distribution, polydispersity index (PDI), solid-state properties, entrapment efficiency (EE) and in vitro drug release of liposomes were investigated. The BBR-loaded liposomes prepared by ethanol-injection and thin-film hydration methods presented an average liposome size ranging from 50 nm to 244 nm and from 111 nm to 449 nm, respectively. The PDI values for the liposomes were less than 0.3, suggesting a narrow size distribution. The EE of liposomes ranged from 56% to 92%. Poorly water-soluble BBR was found to accumulate in the bi-layered phospholipid membrane of the liposomes prepared by the thin-film hydration method. The BBR-loaded liposomes generated by both nanofabrication methods presented extended drug release behavior in vitro. In conclusion, both ethanol-injection and thin-film hydration nanofabrication methods are feasible for generating BBR-loaded oral liposomes with a uniform size, high EE and modified drug release behavior in vitro.

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Utilising Commercially Fabricated Printed Circuit Boards as an Electrochemical Biosensing Platform

Micromachines ◽

10.3390/mi12070793 ◽

2021 ◽

Vol 12 (7) ◽

pp. 793

Author(s):

Uroš Zupančič ◽

Joshua Rainbow ◽

Pedro Estrela ◽

Despina Moschou

Keyword(s):

Printed Circuit Boards ◽

Electrochemical Sensors ◽

Cost Effective ◽

Electrochemical Sensing ◽

Label Free ◽

Circuit Boards ◽

Printed Circuit ◽

Sensing Applications ◽

Electrochemical Biosensing ◽

Pre Treatment

Printed circuit boards (PCBs) offer a promising platform for the development of electronics-assisted biomedical diagnostic sensors and microsystems. The long-standing industrial basis offers distinctive advantages for cost-effective, reproducible, and easily integrated sample-in-answer-out diagnostic microsystems. Nonetheless, the commercial techniques used in the fabrication of PCBs produce various contaminants potentially degrading severely their stability and repeatability in electrochemical sensing applications. Herein, we analyse for the first time such critical technological considerations, allowing the exploitation of commercial PCB platforms as reliable electrochemical sensing platforms. The presented electrochemical and physical characterisation data reveal clear evidence of both organic and inorganic sensing electrode surface contaminants, which can be removed using various pre-cleaning techniques. We demonstrate that, following such pre-treatment rules, PCB-based electrodes can be reliably fabricated for sensitive electrochemical biosensors. Herein, we demonstrate the applicability of the methodology both for labelled protein (procalcitonin) and label-free nucleic acid (E. coli-specific DNA) biomarker quantification, with observed limits of detection (LoD) of 2 pM and 110 pM, respectively. The proposed optimisation of surface pre-treatment is critical in the development of robust and sensitive PCB-based electrochemical sensors for both clinical and environmental diagnostics and monitoring applications.

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Electrochemical Biosensors in Food Safety: Challenges and Perspectives

Molecules ◽

10.3390/molecules26102940 ◽

2021 ◽

Vol 26 (10) ◽

pp. 2940

Author(s):

Antonella Curulli

Keyword(s):

Food Industry ◽

Electrochemical Sensors ◽

Cost Effective ◽

Electrochemical Biosensors ◽

Food Chains ◽

Sensing Systems ◽

Highly Sensitive ◽

Skilled Personnel ◽

Recent Developments ◽

Key Issues

Safety and quality are key issues for the food industry. Consequently, there is growing demand to preserve the food chain and products against substances toxic, harmful to human health, such as contaminants, allergens, toxins, or pathogens. For this reason, it is mandatory to develop highly sensitive, reliable, rapid, and cost-effective sensing systems/devices, such as electrochemical sensors/biosensors. Generally, conventional techniques are limited by long analyses, expensive and complex procedures, and skilled personnel. Therefore, developing performant electrochemical biosensors can significantly support the screening of food chains and products. Here, we report some of the recent developments in this area and analyze the contributions produced by electrochemical biosensors in food screening and their challenges.

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