Cu(I)-based electrodes for glucose monitoring in biofermentation processes

In this document, Cu2O, was widely studied due to its amazing electrodeproperties that will be discuss later. It was modified a total of four sensors (SPCE-DropSens), despite that two of them (P25 and HS-1), due to lack of preparationmethod and characterization were not main focus. Nevertheless, NC-9 and NC-10structured crystalline nanocubes were deeply worked on. Electrochemical testswere run in all four sensors.The structured nanocubes previously referred, NC-9 and NC-10, present sizesof 150-200 nm and 200-900 nm, respectively. The size differences is the mainjustification of the following NC-10 results conclusions. It was visible the lixingof NC-10 modified sensor material to the solution, which were probably due tosort of adherent difficulties.Cuprous oxide in cubic nanostructured material, NC-9, shown a sensitivity,which is the main parameter to characterize the sensor yield, of 840μA mM−1cm−2. Comparing this value with others in the literature is a competitive valuedue to the simplicity of the process and the high sensitivity value. Likewise selec-tivity and repeatibility parameters were also consider good to probably proceedto further future work. The electrooxidation reaction of this sensor that spikesthe current signal undergoes in absorption controlled reaction, against the othersthree sensors.NC-10 electrochemical trials were performed, firstly CV test were successfullyran but later trials were no more consider viable due to the lixing phenomenonreferred previously. That is the reason why it was not calculated NC-10 sensitivity

Progress of Advanced Nanomaterials in the Non-Enzymatic Electrochemical Sensing of Glucose and H2O2

Non-enzymatic sensing has been in the research limelight, and most sensors based on nanomaterials are designed to detect single analytes. The simultaneous detection of analytes that together exist in biological organisms necessitates the development of effective and efficient non-enzymatic electrodes in sensing. In this regard, the development of sensing elements for detecting glucose and hydrogen peroxide (H2O2) is significant. Non-enzymatic sensing is more economical and has a longer lifetime than enzymatic electrochemical sensing, but it has several drawbacks, such as high working potential, slow electrode kinetics, poisoning from intermediate species and weak sensing parameters. We comprehensively review the recent developments in non-enzymatic glucose and H2O2 (NEGH) sensing by focusing mainly on the sensing performance, electro catalytic mechanism, morphology and design of electrode materials. Various types of nanomaterials with metal/metal oxides and hybrid metallic nanocomposites are discussed. A comparison of glucose and H2O2 sensing parameters using the same electrode materials is outlined to predict the efficient sensing performance of advanced nanomaterials. Recent innovative approaches to improve the NEGH sensitivity, selectivity and stability in real-time applications are critically discussed, which have not been sufficiently addressed in the previous reviews. Finally, the challenges, future trends, and prospects associated with advanced nanomaterials for NEGH sensing are considered. We believe this article will help to understand the selection of advanced materials for dual/multi non-enzymatic sensing issues and will also be beneficial for researchers to make breakthrough progress in the area of non-enzymatic sensing of dual/multi biomolecules.Scopu

Nano- and Microstructured Copper/Copper Oxide Composites on Laser-Induced Carbon for Enzyme-Free Glucose Sensors

Low-cost enzyme-free glucose sensors with partial flexibility adaptable for wearable Internet of Things devices that can be envisioned as personalized point-of-care devices were produced by electroplating copper on locally carbonized flexible meta-polyaramid (Nomex) sheets using laser radiation. Freestanding films were annealed in nitrogen and nitrogen/air working environments, leading to the formation of Cu microspheroids and CuO urchins dispersed on the substrate film. The aggregation mechanism, crystallographic properties, surface chemistry, and electrochemical properties of the films were studied using scanning electron microscopy, X-ray diffractometry, transmission electron microscopy, X-ray photoelectron spectroscopy, and cyclic voltammetry. Cu microspheroids and CuO urchins attained activity for glucose detection and showed improvement of amperometric sensitivity to 0.25 and 0.32 mA cm$^{–2}$ mM$^{–1}$, respectively. The CuO urchin film retained its chemical composition after amperometric testing, and, by rinsing, allowed multiple repetitions with reproducible results. This study opens the possibility for the fabrication of durable composite biosensors with tailored shape, capable of implementation in flexible carriers, and microfluidic systems

Advance Nanomaterials for Biosensors

The book provides a comprehensive overview of nanostructures and methods used to design biosensors, as well as applications for these biosensor nanotechnologies in the biological, chemical, and environmental monitoring fields. Biological sensing has proven to be an essential tool for understanding living systems, but it also has practical applications in medicine, drug discovery, food safety, environmental monitoring, defense, personal security, etc. In healthcare, advancements in telecommunications, expert systems, and distributed diagnostics are challenging current delivery models, while robust industrial sensors enable new approaches to research and development. Experts from around the world have written five articles on topics including:Diagnosing and treating intraocular cancers such as retinoblastoma; Nanomedicine in cancer management; Engineered nanomaterials in osteosarcoma diagnosis and treatment; Practical design of nanoscale devices; Detect alkaline phosphatase quantitatively in clinical diagnosis; Progress in the area of non-enzymatic sensing of dual/multi biomolecules; Developments in non-enzymatic glucose and H2O2 (NEGH) sensing; Multi-functionalized nanocarrier therapies for targeting retinoblastoma; Galactose functionalized nanocarriers; Sensing performance, electro-catalytic mechanism, and morphology and design of electrode materials; Biosensors along with their applications and the benefits of machine learning; Innovative approaches to improve the NEGH sensitivity, selectivity, and stability in real-time applications; Challenges and solutions in the field of biosensors

Electrochemical and Photo-electrochemical Reduction of Carbon Dioxide on Copper-Based Catalysts Using the Rotating Ring-Disc Electrode and Development of Novel Electrolyser Devices

Carbon dioxide (CO2) plays an important role in the environment. However, excess emission of CO2 leads to global warming and greenhouse effect to the environment. In order to reduce CO2 emission, various approaches with different methods were performed by different researchers in the past. Electrochemical reduction of CO2 was a promising and commonly used way with hydrocarbons generated as potential products. In this project, rotating ringdisc electrode (RRDE) technique was applied for both electrochemical and photoelectrochemical reduction of CO2. For electrochemical reduction of CO2, copper (I) oxide nanoparticles synthesized from continuous hydrothermal flow synthesis method were used as the catalyst. In a three-electrode electrochemical system, CO2 was reduced to formate in 0.5 M KHCO3 electrolyte between -0.5 V - -0.9 V vs RHE. The highest Faradaic efficiency was 66% at -0.8 V vs RHE. While running the experiments, products generated at the disc electrode was detected by the ring electrode. Scanning of the ring electrode also confirmed the formation of formate. Therefore, RRDE technique was an efficient, convenient and accurate technique for electrochemical reduction of CO2. Cu2O/TiO2 composite material was synthesized via conventional hot-stirring procedure, and the material was then used as photo-electro-catalyst for photo-electrochemical reduction of CO2 in 0.5 M KHCO3 solution. 100 W light was added to the system. RRDE technique was also applied in this series of experiments. Methanol was the major product with highest Faradaic efficiency of 35.9% at -0.7 V vs RHE. Other than diagnostic experiments with three-electrode cell system, reduction of carbon dioxide has been applied in an engineering aspect. Hence, a printed circuit board (PCB) based electrolyser devices have been designed and assembled for electrochemical reduction of CO2. There was no liquid product generated from the devices as dry CO2 was purged into the system. This was confirmed via NMR detection. Carbon monoxide (CO) was the major product generated from electrochemical reduction of CO2 using the PCB-electrolyser device with a Faradaic efficiency of 32.7% at 1.8 V cell potential (i.e. -0.57 V reduction potential). RRDE was successfully used to reduce CO2 electrochemically and photo-electrochemically as well as PCB-integrated device which was applied successfully for electrochemical reduction of CO2. Both techniques could lead to further researches in larger scales for CO2 reduction and its application into industries in the futur

Fourth-generation glucose sensors composed of coppernanostructures for diabetes management: A critical review

More than five decades have been invested in understanding glucose biosensors. Yet, this immensely versatile field has continued to gain attention from the scientific world to better understand and diagnose diabetes. However, such extensive work done to improve glucose sensing devices has still not yielded desirable results. Drawbacks like the necessity of the invasive finger pricking step and the lack of optimization of diagnostic interventions still need to be considered to improve the testing process of diabetic patients. To upgrade the glucose-sensing devices and reduce the number of intermediary steps during glucose measurement, fourth-generation glucose sensors (FGGS) have been introduced. These sensors, made using robust electrocatalytic copper nanostructures, improve diagnostic efficiency and cost-effectiveness. This review aims to present the essential scientific progress in copper nanostructure-based FGGS in the past ten years (2010 – present). After a short introduction, we presented the working principles of these sensors. We then highlighted the importance of copper nanostructures as advanced electrode materials to develop reliable real-time FGGS. Finally, we cover the advantages, shortcomings, and prospects for developing highly sensitive, stable, and specific FGGS

A NOVEL H2S MONITOR USING COPPER (II) OXIDE AND RAMAN SPECTROSCOPY: A PROOF OF CONCEPT

Development of a novel aqueous hydrogen sulfide (H2S) detector is presented in this thesis. Nano copper (II) oxide (CuO) was selected as the detector material. Nano-CuO was synthesized by thermal oxidation and wet synthesis. CuS is produced from the reaction of CuO with H2S and Raman spectroscopy was used for its detection. The research presented in this thesis aimed at optimizing the parameters to produce coupons of CuO that can be used to detect H2S (aq) over the concentration range of 3.81 x10-3 ppm – 3.91 x10-9 ppm (0.1 M – 0.1 µM) by using Raman spectroscopy. Four specific objectives were devised to (1) determine the optimal synthetic technique for CuO, (2) determine which synthesis provides optimal CuO/CuS Raman spectra, (3) determine the linear range and detection limit of H2S by measuring the Raman Spectrum of CuS and, (4) to determine the rate of accumulation of CuS in human serum. The nano-CuO material with the optimal CuO/CuS Raman bands of interest was synthesized by thermal oxidation, where copper mesh (149 µm) was heated at 400 °C in air for 2 hours. The limit of detection of H2S (aq) by the optimal CuO is 1.22 x10-8 ppm (3.59 x10-7 M) with a linear range extending from 7.53 x10-3 – 1.22 x10-8 ppm (6.56 x10-1 – 3.57 x10-7 M). This study has provided new knowledge through (1) the development of a novel methodology to measure H2S (aq) concentration in serum by using CuO and Raman spectroscopy, (2) the discovery that CuO is specific to H2S and does not interact with proteins in human serum or other sulfur compounds at clinical concentrations, (3) determination that H2S (aq) detection is linear over the 7.53 x10-3 – 1.22 x10-8 ppm range with no interference of the Raman band from other biomaterials, and (4) the rate of accumulation is 0.1441 R/s