RESUMO
New voltammetric and flow amperometric methods for the determination of guaifenesin (GFE) using a perspective screen-printed sensor (SPE) with boron-doped diamond electrode (BDDE) were developed. The electrochemical oxidation of GFE was studied on the surface of the oxygen-terminated BDDE of the sensor. The GFE provided two irreversible anodic signals at a potential of 1.0 and 1.1 V (vs. Ag|AgCl|KCl sat.) in Britton-Robinson buffer (pH 2), which was chosen as the supporting electrolyte for all measurements. First, a voltammetric method based on differential pulse voltammetry was developed and a low detection limit (LOD = 41 nmol L-1), a wide linear dynamic range (LDR = 0.1-155 µmol L-1), and a good recovery in the analysis of model and pharmaceutical samples (RSD <3.0 %) were obtained. In addition, this sensor demonstrated excellent sensitivity and reproducibility in the analysis of biological samples (RSD <3.2 %), where the analysis took place in a drop of serum (50 µL) without pretreatment and additional electrolyte. Subsequently, SP/BDDE was incorporated into a flow-through 3D printed electrochemical cell and a flow injection analysis method with electrochemical detection (FIA-ED) was developed, resulting in excellent analytical parameters (LOD = 86 nmol L-1, LDR = 0.1-50 µmol L-1). Moreover, the mechanism of electrochemical oxidation of GFE was proposed based on calculations of HOMO spatial distribution and spectroelectrochemical measurements focused on IR identification of intermediates and products.
Assuntos
Boro , Diamante , Técnicas Eletroquímicas , Eletrodos , Guaifenesina , Boro/química , Guaifenesina/análise , Guaifenesina/química , Diamante/química , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Limite de Detecção , Humanos , OxirreduçãoRESUMO
Electrochemical approaches, along with miniaturization of electrodes, are increasingly being employed to detect and quantify nucleic acid biomarkers. Miniaturization of the electrodes is achieved through the use of screen-printed electrodes (SPEs), which consist of one to a few dozen sets of electrodes, or by utilizing printed circuit boards. Electrode materials used in SPEs include glassy carbon (Chiang H-C, Wang Y, Zhang Q, Levon K, Biosensors (Basel) 9:2-11, 2019), platinum, carbon, and graphene (Cheng FF, He TT, Miao HT, Shi JJ, Jiang LP, Zhu JJ, ACS Appl Mater Interfaces 7:2979-2985, 2015). There are numerous modifications to the electrode surfaces as well (Cheng FF, He TT, Miao HT, Shi JJ, Jiang LP, Zhu JJ, ACS Appl Mater Interfaces 7:2979-2985, 2015). These approaches offer distinct advantages, primarily due to their demonstrated superior limit of detection without amplification. Using the SPEs and potentiostats, we can detect cells, proteins, DNA, and RNA concentrations in the nanomolar (nM) to attomolar (aM) range. The focus of this chapter is to describe the basic approach adopted for the use of SPEs for nucleic acid measurement.
Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Eletrodos , Grafite , Grafite/química , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação , Ácidos Nucleicos/análise , Humanos , DNA/análiseRESUMO
A rapid photoelectrochemical (PEC) sensor was constructed for nitrite detection in food based on the one-step chemical etching strategy of BiOCl/Zn0.5Cd0.5S (BOC/ZCS) nanocomposites by nitrite. BOC/ZCS heterojunction was prepared by a simple coprecipitation method, and it was found that BOC/ZCS showed significant photoelectrochemical (PEC) activity. The results of this study confirmed that the decrease in the photocurrent of the sensor was linked to the etching of ZCS by nitrite under acidic conditions. Under optimized conditions, the BOC/ZCS-based PEC sensor showed good analytical properties for detecting nitrite, with linear ranges of 1-100 µM and 100-600 µM. The detection limit of the sensor was 0.41 µM (S/N = 3). Excellent repeatability, reproducibility, low background noise, and immunity to interference were demonstrated using the proposed system, and satisfactory results were achieved for the nitrite assay using real samples. These results demonstrate a new method for nitrite detection developed using the proposed PEC sensor.
Assuntos
Técnicas Eletroquímicas , Limite de Detecção , Nitritos , Nitritos/análise , Técnicas Eletroquímicas/instrumentação , Bismuto/química , Zinco/química , Zinco/análise , Nanocompostos/química , Processos Fotoquímicos , Contaminação de Alimentos/análiseRESUMO
Excess nitrites are potentially threatening to human health, so it is urgent to develop accurate and sensitive methods. The development of sensors can provide early warning of possible hazards and alert people to protect public health. This work presents an NiSx@MoS2-composite with excellent electrochemical activity, representing a key finding for highly sensitive NO2- detection and sensor development. With the assistance of NiSx@MoS2, this electrochemical sensor has excellent quantitative detection performance. It has a wide detection range (0.0001-0.0020 mg/mL) and a low detection limit (1.863*10-5 mg/mL) for NO2-. This electrochemical sensor maintains excellent specificity among numerous interferences, and it completes the accurate detection of different real food samples. Pleasingly, the electrochemical sensor has satisfactory repeatability stability, and potential for practical applications. It would demonstrate tremendous potential in scientific dietary guidance, food safety detection and other fields.
Assuntos
Dissulfetos , Técnicas Eletroquímicas , Limite de Detecção , Molibdênio , Molibdênio/química , Técnicas Eletroquímicas/instrumentação , Dissulfetos/química , Nitritos/análise , Contaminação de Alimentos/análiseRESUMO
Phoxim, extensively utilized in agriculture as an organothiophosphate insecticide, has the potential to cause neurotoxicity and pose human health hazards. In this study, an electrochemical enzyme biosensor based on Ti3C2 MXene/MoS2@AuNPs/AChE was constructed for the sensitive detection of phoxim. The two-dimensional multilayer structure of Ti3C2 MXene provides a robust framework for MoS2, leading to an expansion of the specific surface area and effectively preventing re-stacking of Ti3C2 MXene. Additionally, the synergistic effect of self-reduced grown AuNPs with MoS2 further improves the electrical conductivity of the composites, while the robust framework provides a favorable microenvironment for immobilization of enzyme molecules. Ti3C2 MXene/MoS2@AuNPs electrochemical enzyme sensor showed a significant response to phoxim in the range of 1 × 10-13 M to 1 × 10-7 M with a detection limit of 5.29 × 10-15 M. Moreover, the sensor demonstrated excellent repeatability, reproducibility, and stability, thereby showing its promising potential for real sample detection.
Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Frutas , Ouro , Nanopartículas Metálicas , Nanocompostos , Compostos Organotiofosforados , Titânio , Ouro/química , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Nanocompostos/química , Frutas/química , Nanopartículas Metálicas/química , Técnicas Biossensoriais/instrumentação , Compostos Organotiofosforados/análise , Titânio/química , Limite de Detecção , Contaminação de Alimentos/análise , Molibdênio/química , Inseticidas/análise , Inseticidas/química , Resíduos de Praguicidas/análise , Resíduos de Praguicidas/químicaRESUMO
In this study, we focused on the successful construction of [(4,4'-bipy/P2Mo17Co)6] modified electrodes using the layer-by-layer assembly method for the sensitive detection of sulfathiazole (ST). The redox reaction between ST and the metal ions in the modified layer leads to the transfer of electrons, resulting in the generation of the electrical signal. The introduction of 4,4'-bipyridine (4,4'-bipy) enhanced the molecular recognition of ST by the modified electrode. Under the combined effect of P2Mo17Co and 4,4'-bipy, the sensor exhibited good performance for ST detection (LOD: 0.5616 µM, linear ST concentration range: 0-50 µM). The spiked recoveries of the two groups were 84.4%-103.2% and 90.9%-109.4% for the determination of ST residues in large yellow croaker and South American white shrimp, respectively. In addition, the electrode showed excellent performance in terms of stability, reproducibility, and anti-interference ability.
Assuntos
Técnicas Eletroquímicas , Eletrodos , Sulfatiazol , Técnicas Eletroquímicas/instrumentação , Animais , Sulfatiazol/química , Contaminação de Alimentos/análise , Sulfatiazóis/química , Sulfatiazóis/análise , Limite de Detecção , Penaeidae/química , OxirreduçãoRESUMO
Rapid screening for foodborne pathogens is crucial for food safety. A rapid and one-step electrochemical sensor has been developed for the detection of Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Salmonella typhimurium (S. typhimurium). Through the construction of aptamer/two-dimensional carboxylated Ti3C2Tx (2D C-Ti3C2Tx)/two-dimensional Zn-MOF (2D Zn-MOF) composites, the recognition elements, signal tags, and signal amplifiers are integrated on the electrode surface. Pathogens are selectively captured using the aptamer, which increases the impedance of the electrode surfaceï¼leads to a decrease in the 2D Zn-MOF current. Bacteria can be rapidly quantified using a one-step detection method and the replacement of aptamers. The detection limits for E. coli, S. aureus, and S. typhimurium are 6, 5, and 5 CFU·mL-1, respectively. The sensor demonstrated reliable detection capabilities in real-sample testing. Therefore, the one-step sensor based on the 2D Zn-MOF and 2D C-Ti3C2Tx has significant application value in the detection of foodborne pathogens.
Assuntos
Técnicas Eletroquímicas , Escherichia coli , Salmonella typhimurium , Staphylococcus aureus , Zinco , Staphylococcus aureus/isolamento & purificação , Salmonella typhimurium/isolamento & purificação , Zinco/análise , Escherichia coli/isolamento & purificação , Técnicas Eletroquímicas/instrumentação , Técnicas Biossensoriais/instrumentação , Estruturas Metalorgânicas/química , Microbiologia de Alimentos , Titânio/química , Limite de Detecção , Eletrodos , Contaminação de Alimentos/análiseRESUMO
In this research, the TT-COF(Fe)@NH2-CNTs was innovatively prepared through a post-modification synthetic process functionalized TT-COF@NH2-CNTs with active site (Fe), where TT-COF@NH2-CNTs was prepared via a one-pot strategy using 5,10,15,20-tetrakis (para-aminophenyl) porphyrin (TTAP), 2,3,6,7-tetra (4-formylphenyl) tetrathiafulvalene (TTF) and aminated carbon nanotubes (NH2-CNTs) as raw materials. The complex TT-COF(Fe)@NH2-CNTs material possessed porous structures, outstanding conductivity and rich catalytic sites. Thus, it can be adopted to construct electrochemical sensor with glassy carbon electrode (GCE). The TT-COF(Fe)@NH2-CNTs/GCE can selectively detect luteolin (Lu) with a wide linear plot ranging from 0.005 to 3 µM and a low limit of detection (LOD) of 1.45 nM (S/N = 3). The Lu residues in carrot samples were determined using TT-COF(Fe)@NH2-CNTs sensor and UV-visible (UV-Vis) approach. This TT-COF(Fe)@NH2-CNTs/GCE sensor paves the way for the quantification of Lu through a cost-efficient and sensitive electrochemical approach, which can make a significant step in the sensing field based on crystalline COFs.
Assuntos
Técnicas Eletroquímicas , Luteolina , Nanotubos de Carbono , Nanotubos de Carbono/química , Luteolina/química , Luteolina/análise , Técnicas Eletroquímicas/instrumentação , Limite de Detecção , Estruturas Metalorgânicas/química , Contaminação de Alimentos/análise , Domínio CatalíticoRESUMO
Nitrite is a common ingredient in the industry and agriculture; it is everywhere, like water, food, and surroundings. Recently, several approaches have been developed to measure the nitrite levels. So, this review was presented as a summary of many approaches utilized to detect the nitrite. Furthermore, the types of information that may be acquired using these methodologies, including optic and electrical signals, were discussed. In electrical signal methods, electrochemical sensors are usually developed using different materials, including carbon, polymers, oxides, and hydroxides. At the same time, optic signals receiving techniques involve utilizing fluorescence chromatography, absorption, and spectrometry instruments. Furthermore, these methodologies' benefits, drawbacks, and restrictions are examined. Lastly, due to the efficiency and fast means of electrochemical detectors, it was suggested that they can be used for detecting nitrite in food safety. Futuristic advancements in the techniques used for nitrite determination are subsequently outlined.
Assuntos
Técnicas Eletroquímicas , Análise de Alimentos , Contaminação de Alimentos , Nitritos , Nitritos/análise , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Contaminação de Alimentos/análise , Análise de Alimentos/métodos , Análise de Alimentos/instrumentaçãoRESUMO
Nonspecific adsorption of biomolecules (notably, proteins) and bacteria from unsterilized food may occur on sensor surfaces, which is still a challenge for food safety sensing. To achieve sensitive detection of unsterilized raw-food materials, in this study, a U-shaped four-in-one peptide with the sequence Ac-FLKLLKKLL-DOPA3-PPPPEEKDQDKEKaa that exhibited anchoring, antifouling, antibacterial, and recognition properties was designed. The peptide-modified sensor surface effectively prevented bacterial adhesion and proliferation while resisting biomolecule adsorption (signal inhibition rate as low as 0.51 % in single-protein solutions). A highly conductive polymer layer of poly(3,4-ethylenedioxythiophene) was introduced to improve the electrochemical performance before U-shaped four-in-one peptide anchoring. The proposed sensor could accurately detect vancomycin, with a wide linear range and limit of detection of 0.05-10 µg mL-1 and 2.06 ng mL-1 (S/N = 3), respectively. Satisfactory recovery rates (101.3-105.3 %) were achieved using diluted fresh goat milk.
Assuntos
Antibacterianos , Compostos Bicíclicos Heterocíclicos com Pontes , Técnicas Eletroquímicas , Contaminação de Alimentos , Cabras , Leite , Peptídeos , Polímeros , Vancomicina , Animais , Leite/química , Polímeros/química , Peptídeos/química , Vancomicina/química , Vancomicina/farmacologia , Vancomicina/análise , Antibacterianos/análise , Antibacterianos/farmacologia , Antibacterianos/química , Contaminação de Alimentos/análise , Compostos Bicíclicos Heterocíclicos com Pontes/química , Técnicas Eletroquímicas/instrumentação , Técnicas Biossensoriais/instrumentação , Incrustação Biológica/prevenção & controleRESUMO
Electrochemical sensors have a broad range of industrial applications due to their sensitivity, speed, and cost-effectiveness. These sensors enable the continuous monitoring and control of critical parameters in various industrial processes. For instance, they are essential in food safety, environmental monitoring, biomedical applications, and pharmaceutical production. In the food industry, electrochemical sensors facilitate the rapid and reliable detection of contaminants and pathogens in food products, thus enhancing product quality and consumer safety. An electrochemical sensor was developed with the molecularly imprinted polymer (MIP) technique to detect deltamethrin with high sensitivity and selectivity. The sensor was fabricated by electrodeposition of Co3O4 on indium tin oxide (ITO), followed by electropolymerization of o-phenylenediamine with deltamethrin as a template molecule. The template molecules were then removed from the modified electrode by a methanol. The MIP-based electrochemical sensor exhibited high sensitivity and selectivity towards deltamethrin. Under the optimized conditions, the LOD values for the MIP/Co3O4/ITO electrode in the first and second linear regressions were 1.53 nM for linear range of 2.82 nM to 56.5 nM and 0.34 µM for linear range of 0.25 µM to 3.98 µM. Moreover, the LOD values for the NIP/Co3O4/ITO electrode in the first and second regressions were 2.43 nM for the linear range of 3.91 nM to 65.0 nM and 726.0 nM for the linear range of 0.023 µM to 4.5 µM. The developed electrochromic pesticide sensor, being an electrochemical-based molecularly imprinted polymer (MIP) sensor incorporating electrochromic materials, enables both target-specific pesticide detection and visual pesticide identification based on color changes dependent on pesticide concentration. Consequently, this system is more advantageous compared to electrochemical-based MIP sensors, as it provides both qualitative and quantitative determinations. The qualitative assessment aims to enhance the ease of use of the sensor, thereby increasing the potential for it to become a commercially viable product by reducing the need for instrumental devices.
Assuntos
Técnicas Eletroquímicas , Polímeros Molecularmente Impressos , Nitrilas , Piretrinas , Piretrinas/análise , Nitrilas/química , Nitrilas/análise , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Polímeros Molecularmente Impressos/química , Contaminação de Alimentos/análise , Impressão Molecular , Polímeros/química , Inseticidas/análise , Limite de DetecçãoRESUMO
A novel voltammetric sensor designed for dopamine (DA) detection is presented utilizing a combination of zeolitic imidazolate framework (ZIF-67) derived cobalt and nitrogen-doped carbon on reduced graphene oxide (Co-N-C/rGO). ZIF-67 cubic crystals were synthesized in situ and deposited onto the graphene oxide (GO) surface through room-temperature reactions. High-temperature calcination resulted in partially collapsed cubic and spherical carbon, while simultaneously reducing GO to rGO. A molecular imprinting resorcinol polymer (MIP) membrane was also in situ applied to the Co-N-C/rGO/glassy carbon electrode (GCE) via electropolymerization. Analyses using cyclic voltammetry, electrochemical impedance, and pulse voltammetry reveal that the modified MIP/Co-N-C/rGO/GCE electrodes show improved electroconductivity and notable electrochemical reactivity towards dopamine. After optimizing detection parameters, the sensor demonstrates a wide linear detection range of 0.01-0.5 and 0.5-100 µmol/L, with a limit of detection (LOD) of 3.33 nmol/L (S/N = 3). Additionally, the sensor displays strong robustness, including excellent selectivity, significant resistance to interference, and long-term stability. It also shows satisfactory recovery in detecting spiked real samples.
Assuntos
Cobalto , Dopamina , Técnicas Eletroquímicas , Eletrodos , Grafite , Imidazóis , Limite de Detecção , Zeolitas , Grafite/química , Dopamina/análise , Dopamina/química , Zeolitas/química , Cobalto/química , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Imidazóis/química , Impressão Molecular , Carbono/química , Nitrogênio/química , Polímeros Molecularmente Impressos/química , Estruturas Metalorgânicas/química , OxirreduçãoRESUMO
Microbial biofilms play a pivotal role in microbial infections and antibiotic resistance due to their unique properties, driving the urgent need for advanced methodologies to study their behavior comprehensively across varied environmental contexts. While electrochemical biosensors have demonstrated success in understanding the dynamics of biofilms, scientists are now synergistically merging these biosensors with microfluidic technology. This combined approach offers heightened precision, sensitivity, and real-time monitoring capabilities, promising a more comprehensive understanding of biofilm behavior and its implications. Our review delves into recent advancements in electrochemical biosensors on microfluidic chips, specifically tailored for investigating biofilm dynamics, virulence, and properties. Through a critical examination of these advantages, properties and applications of these devices, the review highlights the transformative potential of this technology in advancing our understanding of microbial biofilms in different settings.
Assuntos
Biofilmes , Técnicas Biossensoriais , Técnicas Eletroquímicas , Microfluídica , Biofilmes/crescimento & desenvolvimento , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Microfluídica/métodos , Microfluídica/instrumentação , Humanos , Bactérias , Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodosRESUMO
A compact organic electrochemical transistors (OECT) sensor enriched with carbon quantum dots (CQDs) was developed to enhance the transconductance of an electropolymerized poly(3,4-ethylenedioxythiophene) (PEDOT) film, enabling the precise and selective detection of dopamine (DA). Accurate monitoring of DA levels is critical for diagnosing and managing related conditions. Incorporating CQDs, we have achieved a remarkable up to threefold increase in current at the DA detection peak in differential pulse voltammetry. This enhancement showcases superior selectivity even in the presence of high concentrations of interferents like uric acid and ascorbic acid. This material significantly boosts the sensitivity of OECTs for DA detection, delivering an amperometric response with a detection limit of 55 nM and a broader detection range (1 - 500 µM). Our results underscore the potential of low-dimensional carbonaceous materials in creating cost-effective, high-sensitivity devices for detecting DA and other biomolecules. This breakthrough sets the stage for the development of next-generation biosensors for point-of-care diagnostics.
Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes , Carbono , Dopamina , Técnicas Eletroquímicas , Limite de Detecção , Polímeros , Pontos Quânticos , Pontos Quânticos/química , Dopamina/análise , Dopamina/sangue , Carbono/química , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Compostos Bicíclicos Heterocíclicos com Pontes/química , Polímeros/química , Transistores Eletrônicos , Técnicas Biossensoriais/métodos , HumanosRESUMO
Dependable and sensitive glucose (Glu) testing in foodstuff and blood serum is highly desirable to prevent and treat diabetes. Electrochemical quantification of Glu has attracted great interests due to the advantages, including simple operation, higher sensitivity, easy miniaturization, ease of on-site and wearable detection as well as fast response. High costs and environmental dependence of enzymes pose a challenge to the electrochemical enzymatic biosensors. Nonenzymatic electrochemical Glu sensors are urgently needed to aid the Glu detection in human serum and food samples. To fabricate flexible Glu electrochemical sensors, designing suitable electrode substrate and efficient electrocatalyst is of paramount significance. Herein, the porous patterned laser-induced graphene (LIG) was fabricated on polyimide substrates through an efficient laser-inducing technology, and then used directly as the electrode substrate. Electrochemical deposition of NiCo layered double hydroxide (LDH) nanoflakes on the LIG surface was then conducted to achieve NiCo-LDH/LIG electrode as a Glu sensor. Under optimal conditions, this sensor displays a low detection limit of 0.05 µM. Two sets of broad detection linear ranges were found to be from 0.5 to 270 µM and from 0.27 to 3.6 mM, with high sensitivities of 9.750 µA µM-1 cm-2 and 3.760 µA µM-1 cm-2, respectively. The enhanced performance was ascribed to the cooperative action of NiCo-LDH and LIG, in which porous LIG provides extraordinary electroconductibility and a high surface area, while NiCo-LDH offers numerous exposed active sites and outstanding electrocatalytic performance. Practical application was further verified during the Glu detection in human serum and food samples. This research confirms that the NiCo-LDH/LIG composite is a prospective electrode for high-performance Glu sensor and provides a way of developing nonenzymatic electrochemical sensors to analyze the Glu in human serum and food samples, opening new avenues in electrochemical sensing.
Assuntos
Glicemia , Técnicas Eletroquímicas , Grafite , Hidróxidos , Lasers , Grafite/química , Técnicas Eletroquímicas/instrumentação , Hidróxidos/química , Humanos , Glicemia/análise , Eletrodos , Níquel/química , Limite de Detecção , Nanoestruturas/química , Análise de Alimentos , Técnicas BiossensoriaisRESUMO
Electrochemical analysis of glucose monitoring without painful blood collection provides a new noninvasive route for monitoring glucose levels. Thus, in this study, biobased cellulosic papers (methylated and phosphorylated one) based glucose monitoring sensor is developed. To achieve high hydrophilicity, microfibrillated cellulose (MFC) were functionalized using hexokinase mediated phosphorylation (-OH to -[Formula: see text]). The instinctive increased surface charge density from 36.2 ± 3.4 to 118.4 ± 1.2 µmol/g and decrease contact angle (45°-22°) confirms the increased hydrophilicity of paper. Furthermore, functionalized phos-MFC paper increase the capillary flow of sweat, required low quantity (1 µl) of sweat for accurate analysis of glucose level. Additionally, chemically induced methyl groups (-CH3) make the sensor more barrier to other chemicals. In addition, a multilayer patch design combined with sensor miniaturization was used to lead to an increase in the efficiency of the sweat collection and sensing processes. Besides, this paper sensor integrated with artificial transdermal drug delivery unit (agarose gel as skin) for monitoring glucose levels in sweat. The patch monitoring system increase the accuracy of sensing with fluctuation in sweat vol. (1-4 µl), temperature (20-70 °C), and pH (4.0-7.0). In addition, temperature dependency artificial transdermal delivery (within agarose gel) of drug metformin agrees the measurement accuracy of sensor, called "switch system" without any error. As a result, the reported MFC paper based multi-patch disposable sensing system provides a novel closed-loop solution for the noninvasive sweat-based management of diabetes mellitus.
Assuntos
Técnicas Biossensoriais , Celulose , Glucose , Papel , Suor , Suor/química , Celulose/química , Humanos , Glucose/análise , Glucose/metabolismo , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação , Interações Hidrofóbicas e Hidrofílicas , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Monitorização Fisiológica/métodos , Monitorização Fisiológica/instrumentação , Automonitorização da Glicemia/instrumentação , Automonitorização da Glicemia/métodosRESUMO
Herein, the electrochemical sensing efficacy of carboxylic acid functionalized multiwalled carbon nanotubes (C-MWCNT) intertwined with coexisting phases of gadolinium monosulfide (GdS) and gadolinium oxide (Gd2O3) nanosheets is explored for the first time. The nanocomposite demonstrated splendid specificity for nonenzymatic electrochemical detection of uric acid (UA) in biological samples. It was synthesized using the coprecipitation method and thoroughly characterized. The presence of functional groups and disorder in the as-synthesized nanocomposite are confirmed using Fourier transform infrared spectroscopy and Raman spectroscopy. Furthermore, field emission scanning electron microscopy, high-resolution transmission electron microscope, X-ray powder diffraction, and X-ray photoelectron spectroscopy provides a clear understanding of the morphology, coexisting phases, and elemental composition of the as-synthesized nanocomposites. The differential pulse voltammetry technique was utilized to elaborate the electrochemical sensing of UA using a GdS-Gd2O3/C-MWCNT modified glassy carbon electrode (GCE), The sensor showed an enhanced current response by more than 2-fold compared to bare GCE. Also, the sensor's performance was further improved by dispersing the nanocomposite in an ionic liquid with the exceptional reproducibility (SD = 0.0025, n = 3). The fabricated UA sensor GdS-Gd2O3/C-MWCNT/IL/GCE demonstrated a wide linear detection range from 0.5-30 µM and 30-2000 µM, effectively covering the entire physiological range of UA in biological fluids with a limit of detection (LOD) of 0.380 µM (+3SD of blank) and a sensitivity of 356.125 µA mM-1 cm-2. Moreover, the electrodes exhibited storage stability for 2 weeks with decrease in zero-day current by only 4.5%. The sensor was validated by quantifying UA in 12 unprocessed clinical human urine and serum samples, and its comparison with the gold standard test yielded remarkable results (p < 0.05). Hence, the proposed nonenzymatic electrochemical UA sensor is selective, sensitive, reproducible, and stable, making it reliable for point-of-care diagnostics.
Assuntos
Técnicas Eletroquímicas , Gadolínio , Nanotubos de Carbono , Ácido Úrico , Humanos , Nanotubos de Carbono/química , Ácido Úrico/sangue , Ácido Úrico/urina , Ácido Úrico/química , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Gadolínio/química , Eletrodos , Nanocompostos/química , Limite de Detecção , Ácidos Carboxílicos/químicaRESUMO
A machine learning-assisted 3D-printed conducting microneedle-based electrochemical sensing platform was developed for wireless, efficient, economical, and selective determination of buprenorphine. The developed microneedle array-based sensing platform used 3D printing and air spray coating technologies for rapid and scalable manufacturing of a conducting microneedle surface. Upon optimization and understanding of the electrode stability, redox behavior, and electrochemical characteristics of as-prepared conducting microneedle array, the developed electrochemical platform was investigated for monitoring different levels of buprenorphine in the artificial intestinal fluid and found to be highly sensitive and selective towards buprenorphine for a wide detection range from 2 to 140 µM, with a low limit of detection of 0.129 µM. Furthermore, to make the sensing platform user accessible, the experimentally recorded sensing data was used to train a machine learning model and develop a web application for the numerical demonstration of buprenorphine levels at the point of site. Finally, the proof-of-concept study demonstrated that by advancing our prevailing 3D printing and additive manufacturing techniques, a low-cost, user-accessible, and compelling wearable electrochemical sensor could be manufactured for minimally invasive determination of buprenorphine in interstitial fluid.
Assuntos
Buprenorfina , Técnicas Eletroquímicas , Agulhas , Impressão Tridimensional , Buprenorfina/análise , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Carbono/química , Limite de Detecção , Humanos , Aprendizado de Máquina , Estudo de Prova de ConceitoRESUMO
The preparation of a hybrid nanomaterial is reported by covalently attaching 3,5-dinitrobenzoic acid groups to the surface of oxidized multi-walled carbon nanotubes using 1,6-diaminohexane as cross-linking agent. This nanomaterial, modified with the redox mediator, was used as transduction element to construct an amperometric sensor for the efficient indirect determination of glutathione reductase at a low working potential of - 0.05 V, through the oxidation of unconsumed nicotinamide adenine dinucleotide phosphate (NADPH) in the enzymatic reaction. The sensor exhibited an excellent linear response in the range 1.6 to 174 µU/µL, with high reproducibility and selectivity. The developed device was successfully validated in real samples, accurately determining the active enzyme in diluted human serum, making it a promising alternative for the determination of glutathione reductase and other related NADPH-dependent enzymes with relevance in clinical analysis.
Assuntos
Técnicas Eletroquímicas , Eletrodos , Glutationa Redutase , Nanotubos de Carbono , Nanotubos de Carbono/química , Humanos , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Glutationa Redutase/metabolismo , Técnicas Biossensoriais/métodos , NADP/química , NADP/metabolismo , Oxirredução , Nitrobenzoatos/química , Limite de DetecçãoRESUMO
Cellular heterogeneity plays a significant role in understanding biological processes, such as cell cycle and disease progression. Microfluidics has emerged as a versatile tool for manipulating single cells and analyzing their heterogeneity with the merits of precise fluid control, small sample consumption, easy integration, and high throughput. Specifically, integrating microfluidics with electrical techniques provides a rapid, label-free, and non-invasive way to investigate cellular heterogeneity at the single-cell level. Here, we review the recent development of microfluidic-based electrical strategies for single-cell manipulation and analysis, including dielectrophoresis- and electroporation-based single-cell manipulation, impedance- and AC electrokinetic-based methods, and electrochemical-based single-cell detection methods. Finally, the challenges and future perspectives of the microfluidic-based electrical techniques for single-cell analysis are proposed.