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In this work, the authors reported the hybrid architecture of carbon nanotube (CNT)–zinc oxide (ZnO) nanowire as a multi‐functional probe in amperometric immunosensor for the detection of urine albumin. Low‐cost substrate such as glass is possible because of novel low‐temperature growth process of CNT/ZnO nanowires as a multi‐function electrode in...
Citations
... Several biological sensing techniques have been explored as alternative tools for detecting albumin in urine and blood samples [18][19][20][21]. The need for a highly selective, rapid, simple, and cost-effective biosensing platform has spurred interest in nanomaterials with unique optical, electronic, and catalytic properties that make them ideal candidates for advanced biosensing systems [22,23]. Graphene, a two-dimensional single-layer carbon material, has garnered attention for its distinctive features such as good water dispersibility, remarkable mechanical strength, and excellent electrical and thermal properties. ...
This study presents the development of a portable fluorometer with a smartphone application designed to facilitate the early screening of chronic kidney and renal diseases by enabling the sensitive detection of urinary albumin. Utilizing a fluorescence-based aptasensor, the device achieved a linear calibration curve (0.001–1.5 mg/mL) with a linearity of up to 0.98022 and a detection limit of 0.203 µg/mL for human serum albumin (HSA). The analysis of 130 urine samples demonstrated comparable performance between this study’s fluorometer, a commercial fluorometer, and the standard automated method. These findings validate the feasibility of the portable fluorometer and aptasensor combination as a reliable instrument for the sensitive and specific measurement of HSA in urine samples. Moreover, the fluorometer’s portability offers potential applications in portable point-of-care testing, enhancing its utility in clinical settings for early disease screening.
... To date few papers have reported data on ZnO-based immunosensors. Legionella pneumophila [61], cortisol [62], ovarian cancer antigen CA-125/MUC126 [63], human salivar alpha-amylase [64], and urine albumin [65] have been detected using ZnO-based immunosensors. In the case of H-IgG detection, ZnO was used to build field-effect transistor [66] and electrochemical sensors [67]. ...
Immunoglobulin G (IgG), a type of antibody, represents approximately 75% of serum antibodies in humans, and is the most common type of antibody found in blood circulation. Consequently, the development of simple, fast and reliable systems for IgG detection, which can be achieved using electrochemical sandwich-type immunosensors, is of considerable interest. In this study we have developed an immunosensor for human (H)-IgG using an inexpensive and very simple fabrication method based on ZnO nanorods (NRs) obtained through the electrodeposition of ZnO. The ZnO NRs were treated by electrodepositing a layer of reduced graphene oxide (rGO) to ensure an easy immobilization of the antibodies. On Indium Tin Oxide supported on Polyethylene Terephthalate/ZnO NRs/rGO substrate, the sandwich configuration of the immunosensor was built through different incubation steps, which were all optimized. The immunosensor is electrochemically active thanks to the presence of gold nanoparticles tagging the secondary antibody. The immunosensor was used to measure the current density of the hydrogen development reaction which is indirectly linked to the concentration of H-IgG. In this way the calibration curve was constructed obtaining a logarithmic linear range of 10–1000 ng/mL with a detection limit of few ng/mL and good sensitivity.
... To date few papers have reported data on ZnO-based immunosensors. Legionella pneumophila [65], cortisol [66], ovarian cancer antigen CA-125/MUC126 [67], human salivar alpha-amylase [68], and urine albumin [69] have been detected using ZnO-based immunosensors.. In the case of H-IgG detection, ZnO was used to build field-effect transistor [70] and electrochemical sensors [71]. ...
Immunoglobulin G (IgG), a type of antibody, represents approximately 75% of serum antibodies in humans, and is the most common type of antibody found in blood circulation Consequently, the development of simple, fast and reliable systems for IgG detection are of considerable interest which can be achieved using electrochemical sandwich-type immunosensors. In this study we have developed an immunosensor sub-strate using an inexpensive and very simple fabrication method based on ZnO nanorods obtained through the electrodeposition of ZnO. The ZnO nanorods were treated by electrodepositing a layer of reduced gra-phene oxide to ensure an easy immobilization of the antibodies. On this substrate, the sandwich configura-tion of the immunosensor was built through different incubation steps, that were all optimized. The im-munosensor is electrochemically active thanks to the presence of gold nanoparticles tagging the secondary antibody, therefore it has been used to measure the current density of the hydrogen development reaction which is indirectly linked to the concentration of H-IgG antigens. In this way the calibration curve was constructed obtaining a linear range of 1-100 ng / ml with a detection limit of few ng / mL and good sensi-tivity.
... A number of researchers have made efforts to solve the drift problem of E-noses. In addition to straightforward attempts on gas sensor material, structure, and fabrication improvements [6][7][8], the algorithm approach is a popular choice counteracting the negative effect of drift. Commonly, the algorithm approach can be divided into two manners based on the usage of category information of drift correction samples. ...
Drift compensation is an important issue in an electronic nose (E-nose) that hinders the development of E-nose’s model robustness and recognition stability. The model-based drift compensation is a typical and popular countermeasure solving the drift problem. However, traditional model-based drift compensation methods have faced “label dilemma” owing to high costs of obtaining kinds of prepared drift-calibration samples. In this study, we have proposed a calibration model for classification utilizing a single category of drift correction samples for more convenient and feasible operations. We constructed a multi-task learning model to achieve a calibrated classifier considering several demands. Accordingly, an associated solution process has been presented to gain a closed-form classifier representation. Moreover, two E-nose drift datasets have been introduced for method evaluation. From the experimental results, the proposed methodology reaches the highest recognition rate in most cases. On the other hand, the proposed methodology demonstrates excellent and steady performance in a wide range of adjustable parameters. Generally, the proposed method can conduct drift compensation with limited one-class calibration samples, accessing the top accuracy among all presented reference methods. It is a new choice for E-nose to counteract drift effect under cost-sensitive conditions.
... Uncited reference [36], [37]. ...
We report a new highly selective detection platform for human albumin (HA) in urine based on aptamer-functionalised magnetic particles. Magnetic separation and re-dispersion was utilised to expose the HA-bound particles to a methylene blue solution. A second magnetic collection step was then used to allow the methylene blue supernatant to be reduced at an unmodified screen-printed electrode. Since methylene blue adsorbs to HA, the reduction current fell in proportion to HA concentration. There was no interference from compounds such as dopamine, epinephrine, vanillylmandelic acid, normetanephrine, metanephrine and creatinine in artificial urine at the concentrations at which they would be expected to appear. A calibration equation was derived to allow for the effect of pH on the response. This enabled measurement to be made directly in clinical urine samples of varying pH. After optimisation of experimental parameters, the total assay time was 40 min and the limit of detection was between 0.93 - 1.16 μg mL⁻¹, depending on the pH used. HA could be detected up to 400 μg mL⁻¹, covering the range from normoalbuminuria to macroalbuminuria. Analysis of urine samples of patients, with diabatic nephropathy, type I & II diabetes mellitus and chronic kidney disease, from a local hospital showed good agreement with the standard urinary human albumin detection method.
... MWCNTÀZnO nanofiber modified electrodes were used for the generation of an ECL immunosensor which detect atrazine pesticide in drinking water [84]. Similarly hybrids of CNT/ZnO nanowires were used in amperometric sensors to detect urea albumin [85] and CNTÀCOOHs/ZnO luminophores were incorporated in an ECL immunosensor to detect tetracycline in fishpond water [86]. This leads to the emergence of the fact that carbon nanotubes (CNTs) were considered as excellent supporting material for the development of ultrasensitive ZnO-based ECL sensors due to their conductance, mesoporous character, and easy modification with different functional groups. ...
Zinc oxide nanoparticles (ZnO NPs) have gained remarkable interest due to their biomedical applications, photochemical and high catalytic abilities, suitability for therapeutic intervention, and their antifungal and antibacterial activities. Their nanosize enables augmented precise surface area as the condensed particle size results in enhanced particle surface reactivity. With the emergence of ZnO NPs in nature, their toxicity assessment has become an instantaneous affair. This chapter covers factors affecting the antimicrobial properties of ZnO NPs. We have summarized the toxicity assessment methods and antimicrobial properties of ZnO nanostructures. The mechanisms of toxicity of these ZnO nanomaterials have been explained in detail in this chapter.
... MWCNTÀZnO nanofiber modified electrodes were used for the generation of an ECL immunosensor which detect atrazine pesticide in drinking water [84]. Similarly hybrids of CNT/ZnO nanowires were used in amperometric sensors to detect urea albumin [85] and CNTÀCOOHs/ZnO luminophores were incorporated in an ECL immunosensor to detect tetracycline in fishpond water [86]. This leads to the emergence of the fact that carbon nanotubes (CNTs) were considered as excellent supporting material for the development of ultrasensitive ZnO-based ECL sensors due to their conductance, mesoporous character, and easy modification with different functional groups. ...
ZnO has attracted the research fraternity worldwide owing to its fascinating properties. Its biosafety and biocompatibility have enabled researchers to exploit it in the area of biomedical sciences and healthcare monitoring. ZnO nanostructures possess great prospects in medical and diagnostic fields for disease identification and therapeutics. Their applications as biosensor diagnostic tools are being explored extensively for point-of-care applications. In this article, we have classified the ZnO-based biosensors according to the analyte used, like immunosensors, nucleic acid biosensors, aptamer-based biosensors, etc. Apart from this, we also have summarized the use of ZnO nanostructures for sensing biomolecules like glucose, cholesterol, urea, and uric acid. We here tried to review some of the key advancements in ZnO nanostructure–based biosensors and evaluate their properties with the aim of rousing greater interest in improving biosensor development for medical diagnosis.
Thin-film nano-architecting is a promising approach that controls the properties of nanoscale surfaces to increase their interdisciplinary applications in a variety of fields. In this context, zinc oxide (ZnO)-based various nano-architectures (0–3D) such as quantum dots, nanorods/nanotubes, nanothin films, tetrapods, nanoflowers, hollow structures, etc. have been extensively researched by the scientific community in the past decade. Owing to their unique surface, charge transport,
optoelectronic properties, and reported biomedical applications, ZnO has been considered one of the most important futuristic bio-nanomaterials. This review is focused on the design/synthesis and engineering of 0–3D nano-architecture ZnO-based thin films and coatings with tunable characteristics for multifunctional biomedical applications. Although ZnO has been extensively researched, ZnO thin films composed of 0–3D nanoarchitectures with promising thin film device bio-nanotechnology applications have rarely been reviewed. The current review focuses on important details about the technologies used to make ZnO-based thin films, as well as the customization of properties related to bioactivities, characterization, and device fabrication for modern biomedical uses that are relevant. It features biosensing, tissue engineering/wound healing, antibacterial, antiviral, and anticancer activity, as well as biomedical diagnosis and therapy with an emphasis on a better understanding of the mechanisms of action. Eventually, key issues, experimental parameters and factors, open challenges, etc. in thin film device fabrications and
applications, and future prospects will be discussed, followed by a summary and conclusion.
Carbon nanotubes (CNTs) have been utilized in many gas sensor structures, individually or in hybrid form with other materials to enhance their gas sensing properties. CNT and CNT–ZnO nanowire structures were fabricated by plasma-enhanced chemical vapor deposition (PECVD) and hydrothermal growth methods to explore and compare their gas sensing properties. The morphologies of the fabricated samples were characterized using scanning electron microscopy and Fourier-transform infrared spectroscopy. Gas sensing properties of fabricated samples were assessed at different atmospheric and thermal conditions. Results verified CNT–ZnO has two times higher response than the CNT sample toward volatile organic compounds vapor at room temperature. A longer lifetime and more stability are other advantages of the CNT–ZnO hybrid. Moreover, it is shown that increasing the length of ZnO nanowires exhibits a higher response to examined analytes. It was found that increasing the temperature causes different sensing regimes in CNT and CNT–ZnO samples. At all ranges of temperatures, the resistance of CNT samples increased in the presence of reducing gases while CNT–ZnO samples exhibited similar behavior only below ∼90 °C. At elevated temperatures, their resistances decreased in response to the same gases.
