Electrochemical Biosensor For Simultaneous Detection Research Articles

Silver@copper-polyaniline nanotubes: Synthesis, characterization and biosensor analytical study

We introduce silver-copper nanoparticles incorporated into polyaniline (PANI) nanotubes using a straightforward and efficient reduction process. In this regard, PANI nanotubes with amine groups were fabricated through oxidation polymerization, followed by the attachment of Ag and Cu precursors to enable the synthesis of Ag-Cu bimetallic nanoparticles (NPs) on the pre-formed PANI nanotubes with the use of hydrazine as a reducing agent. The structural characterization of the synthesized NPs was investigated by UV–Vis spectrophotometer (UV–Vis), Dark-field emission, (EDX), X-ray diffraction (XRD) and field emission (FESEM), while the electrochemical properties were estimated by (CV) and differential pulse voltammetry (DPV). The findings indicated that the Ag-Cu NPs were present in the nanoscale range, well-dispersed, and attached to the surface of PANI nanotubes. Electrochemical investigations revealed that the Ag-Cu@PANI nanotube electrode demonstrated efficient electrooxidation of dopamine and hydroquinone without any interfering reactions, suggesting its potential use as an electrochemical biosensor for simultaneous detection of dopamine and hydroquinone. The proposed NPs-based biosensor was connected to concurrently identify dopamine and hydroquinone, illustrating moo distinguish Confinements of 0.46 µM for dopamine and 0.23 mM for hydroquinone, separately. Additionally, the manufactured sensor identified on a wide direct run the dopamine (5–25 µM), and hydroquinone (0.5–2.5 mM). Alongside these promising comes about, the Ag-Cu@PANI nanotube actualized great solidness and reproducibility, making it a favorable stage for electrochemical biosensing of dopamine and hydroquinone.

A DNA tetrahedral scaffolds-based electrochemical biosensor for simultaneous detection of AFB1 and OTA

Herein, a bifunctional electrochemical biosensor based on the DNA tetrahedral scaffolds (TDNs) was proposed, OTA@TDNs and AFB1@TDNs were adopted for electrochemical signal output in response to OTA and AFB1 concentration, simultaneously. In order to increase the conductivity of the biosensor, highly porous gold (HPG) was loaded on electrode surface by pulse electrodeposition. Under optimal conditions, the PFc displayed a linear range with AFB1 concentration between 0.05 ∼ 360 ng·mL−1 with the LOD of 3.5 pg·mL−1. And the PMB selective and sensitive responses to OTA are achieved with a linear range of 0.05 ∼ 420 ng·mL−1 and a LOD of 2.4 pg·mL−1. This biosensor has high sensitivity, selectivity and stability for OTA and AFB1 detection in peanut samples. The approach streamlines the experimental procedure, leading to significantly improve the detection efficiency of mycotoxins. Collectively, this method suggest a novel approach for the detection and monitoring of OTA and AFB1 in food sample.

Vertical Graphene-Based Printed Electrochemical Biosensor for Simultaneous Detection of Four Alzheimer's Disease Blood Biomarkers.

Early detection and timely intervention play a vital role in the effective management of Alzheimer's disease. Currently, the diagnostic accuracy for Alzheimer's disease based on a single blood biomarker is relatively low, and the combined use of multiple blood biomarkers can greatly improve diagnostic accuracy. Herein, we report a printed electrochemical biosensor based on vertical graphene (VG) modified with gold nanoparticles (VG@nanoAu) for the simultaneous detection of four Alzheimer's disease blood biomarkers. The printed electrochemical electrode array was constructed by laser etching and inkjet printing. Then gold nanoparticles were modified onto the working electrode surface via electrodeposition to further improve the sensitivity of the sensor. In addition, the entire printed electrochemical sensing system incorporates an electrochemical micro-workstation and a smartphone. The customized electrochemical micro-workstation incorporates four electro-chemical control chips, enabling the sensor to simultaneously analyze four biomarkers. Consequently, the printed electrochemical sensing system exhibits excellent analytical performance due to the large surface area, biocompatibility, and good conductivity of VG@nanoAu. The detection limit of the sensing system for Aβ40, Aβ42, T-tau, and P-tau181 was 0.072, 0.089, 0.071, and 0.051 pg/mL, respectively, which meets the detection requirements of Alzheimer's disease blood biomarkers. The printed electrochemical sensing system also exhibits good specificity and stability. This work has great value and promising prospects for early Alzheimer's disease diagnosis using blood biomarkers.

High-performance strategy for the construction of electrochemical biosensor for simultaneous detection of miRNA-141 and miRNA-21 as lung cancer biomarkers

In this study, the dual signal-labeled hairpin-structured DNA (dhDNA)-based probes have been developed to construct a novel nano-biosensor. This one hairpin-structured probe consists of a thiolated methylene blue-labeled hairpin capture probe (MB-HCP) as an inner reference probe and a ferrocene-modified anti-miRNA-21 DNA probe (Fc-AP-21). This novel integrated structure of MB-HCP and Fc-AP-21 was designed on one sensing interface for sensitive and simultaneous detection of the miRNA-141 and miRNA-21 in one single assay. The proposed strategy has a good ability to reduce the interference of environmental factors and it was designed to control the initial responses of Fc-AP to MB-HCP ((IFc/IMB)0) at a 1:1 ratio, which is desirable for further increase in the sensitivity and signal-to-noise ratio of the biosensor operation. Besides, the biosensor was first prepared by immobilizing the dhDNA (Fc-AP-21/MB-HCP) onto the modified glassy carbon electrode. After hybridization with the anti-miRNA-141 complementary sequence (ACP-141), the dhDNA structure was compelled to open and form the final structure of the biosensor. Also, the miRNA-141 and miRNA-21 dissociate duplex structures due to the highly matched sequences between the miRNA-141 and ACP-141 and the miRNA-21 and Fc-AP-21. A linear relationship was found between the logarithm of miRNA-141 and miRNA-21 concentrations and the signal changes. This feature was used to detect the two miRNAs. This sensitive biosensor provided low detection limits of 0.89 and 1.24 fM for the miRNA-141 and miRNA-21, respectively. Also, it has wide linear ranges of 2.0 to 105 fM, with highly selective and accurate results for its application in plasma samples. Therefore, this strategy can be promising as a suitable platform for simultaneous and early detection of various cancer biomarkers.

A Flexible Dual-Analyte Electrochemical Biosensor for Salivary Glucose and Lactate Detection.

Electrochemical biosensors have been widely applied in the development of metabolite detection systems for disease management. However, conventional intravenous and fingertip blood tests are invasive and cannot track dynamic trends of multiple metabolites. Among various body fluids, saliva can be easily accessed and is regarded as a promising candidate for non-invasive metabolite detection. Recent works on the development of electrochemical biosensors for monitoring salivary metabolites have demonstrated high sensitivity and wide linear range. However, most of this research has been focused on salivary detection of a single metabolite. Here, we present a dual-channel electrochemical biosensor for simultaneous detection of lactate and glucose in saliva based on a flexible screen-printed electrode with two working electrodes. The sensitivities of glucose and lactate channels were 18.7 μA/(mM·cm2) and 21.8 μA/(mM·cm2), respectively. The dual-channel biosensor exhibited wide linear ranges of 0–1500 μM for the glucose channel and 0–2000 μM for the lactate channel and the cross-talk between the two detection channels was negligible, which made it adequately suitable for sensing low-level salivary metabolites. Such attractive characteristics demonstrate the potential of this dual-analyte biosensor in the development of wearable devices for monitoring disease progression and fitness.

An electrochemical biosensor for simultaneous detection of breast cancer clinically related microRNAs based on a gold nanoparticles/graphene quantum dots/graphene oxide film.

A label-free multiplexed electrochemical biosensor based on a gold nanoparticles/graphene quantum dots/graphene oxide (AuNPs/GQDs/GO) modified three-screen-printed carbon electrode (3SPCE) array is successfully constructed to detect miRNA-21, miRNA-155, and miRNA-210 biomarkers for the first time. Redox species (anthraquinone (AQ), methylene blue (MB), and polydopamine (PDA)) are used as redox indicators for anchoring capture miRNA probes, which hybridize with the complementary targets, miRNA-21, miRNA-155, and miRNA-210, respectively. After three target miRNAs are present, the square wave voltammetry (SWV) scan displays three well-separated peaks. Each peak indicates the presence of one miRNA, and its intensity quantitatively correlates with the concentration of the corresponding target analyte. This phenomenon results in the substantial decline of the SWV peak current of the redox probes. The developed AuNPs/GQDs/GO-based biosensor reveals excellent performance for simultaneous miRNA sensing. It offers a wide linear dynamic range from 0.001 to 1000 pM with ultrasensitive low detection limits of 0.04, 0.33, and 0.28 fM for the detection of miRNA-21, miRNA-155, and miRNA-210, respectively. It also presents high selectivity and applicability for the detection of miRNAs in human serum samples. This multiplex label-free miRNA biosensor has great potential for applications in breast cancer diagnosis.

Polycrystalline boron-doped diamond-based electrochemical biosensor for simultaneous detection of dopamine and melatonin

In this study, boron-doped diamond (BDD) electrodes with varied B contents are prepared to determine the feasibility of the direct usage of BDD as an electrochemical biosensor without any modification. The electrochemical performance of the electrodes was investigated through the characterization of electrochemical impedance spectroscopy for potassium ferricyanide/potassium ferrocyanide (K3Fe(CN)6/K4Fe(CN)6) redox couples, as well as through qualitative and quantitative analysis of the two biomolecules dopamine (DA) and melatonin (MLT). The results show that the B content of BDD is the primary parameter for controlling the electrocatalytic current, that is, the response sensitivity. However, the abundant crystal planes and low background current are the key factors in improving the selectivity of the biomarkers to identify multiple analytes. Considering the catalytic current and its ability to distinguish the biomolecules, BDD with a B source carrier gas flow rate of 18 sccm is used as the sensing electrode for the simultaneous detection of DA and MLT. The response peak potential difference reaches 500 mV, and the linear concentration range for the two analytes is 0.4–600 μM, with detection limits of 0.1 μM for DA and 0.003 μM for MLT. These results match those observed for electrochemical sensors modified by various sensitive materials. BDD electrodes show good chemical resistance, good stability, and no pollution and are suitable for long-term usage as biomarker sensors.

Peptide nucleic acid-based electrochemical biosensor for simultaneous detection of multiple microRNAs from cancer cells with catalytic hairpin assembly amplification

Herein we demonstrated a facile electrochemical method for simultaneous detection of miRNA21 and miRNA155 using a peptide nucleic acids (PNAs)-modified gold electrode coupled with the target-catalyzed hairpin assembly (CHA) strategy. In the presence of the target miRNA, the CHA was triggered selectively between two hairpins with one ferrocene (Fc) or methylene blue (MB) labelled. The resulting redox-active group modified CHA products (Fc-CHA21 or MB-CHA155) were then specifically captured by the PNA probes (PNA21 or PNA155) attached on the surface of a gold electrode, which bring the Fc and MB labels into close proximity to generate apparently enhanced electrochemical signals for sensitive and simultaneous detecting of low amount miRNA21 and miRNA155 in cancer cells. This assay was highly selective for discriminating miRNAs with similar sequences and has detection limits of 2.49 fM and 11.63 fM for miRNA21 and miRNA155, respectively. The feasibility of the method for sensitive determination of miRNA21 and miRNA155 from human cancer cells was also demonstrated. This method thus has great potential to be applied for simultaneous detecting of a variety of miRNA biomarkers for clinic applications due to its simple, sensitive and accurate features.

An enzyme-free electrochemical biosensor for simultaneous detection of two hemophilia A biomarkers: Combining target recycling with quantum dots-encapsulated metal-organic frameworks for signal amplification

A sensitive and selective electrochemical method for simultaneous detection of two hemophilia A-related microRNAs (miR-1246 and miR-4521) was developed. This detection tactic was based on gold nanoparticles (AuNPs), heavy metals quantum dots-encapsulated metal-organic frameworks (QDs@ZIF-8), and catalytic hairpin assembly (CHA) for signal application. Primarily, hairpins H1 and H2 were hybridized with targets miR-1246 (T1) and miR-4521 (T2) for forming H1-T1 and H2-T2 duplex stranded DNAs (dsDNAs) that were able to open the hairpins H3 and H4 for the formation of H1–H3 and H2–H4 dsDNAs. Meanwhile, lots of H1–H3 and H2–H4 dsDNAs were created by releasing the target to take part in the next cycle for signal amplification. And then single stranded fragments of H1–H3 and H2–H4 dsDNAs were utilized for hybridizing the PbS@ZIF-8-S1 and CdS@ZIF-8-S2 in order to amplify the electrochemical signal. The diagnosis of corresponding target miRs using differential pulse voltammetry has been possible by releasing Pb (II) and Cd (II) ions from PbS@ZIF-8 and CdS@ZIF-8 tags by HCI leaching. In this context, encapsulation of heavy metals quantum dots (QDs) was done in zeolitic imidazolate framework-8 (ZIF-8) to form QDs@ZIF-8 muti-core-shell particles by in situ growth of ZIF-8 in the presence of QDs. Since the quantity of QDs tagged to each target miRs grows massively, being resulted from a huge number of QDs that encapsulated in each QDs@ZIF-8 label, the sensitivity of the biosensor using QDs@ZIF-8 particles as signal tags is about 15 times that of a biosensor using QDs as signal tags. Several conditions of determination like incubation time for labeling and capture probe, HCl leaching time, and reaction time of CHA were optimized. Under the optimized conditions, this assay allowed the detection of target miRs in the range of 1 fM to 1 μM with detection limits of 0.19 fM and 0.28 fM for miR-1246 and miR-4521 (S/N = 3). The biosensor can discriminate complementary, 1-base mismatched and non-complementary sequences quite well, according to the catalytic hairpin assembly. Furthermore, the biosensor was utilized efficiently for quick and direct analysis of microRNAs in human serum. Thus, this tactic presents an innovative platform for microRNAs expression profiling in biomedical research and clinical diagnosis.

Simultaneous Determination of Glutamate and Calcium Ion in Rat Brain during Spreading Depression and Ischemia Processes

Abstract In vivo chemical analysis is an important aspect in exploring brain functions. Brain function realization depends on multiple chemical molecules working together. The determination of one single chemical substance is difficult to clarify the signal transduction and disease occurrence. Thus, it is particularly important to simultaneous determination of multiple biological species in the brain. In this study, we designed and constructed a dual-functional electrochemical biosensor for simultaneous detection of glutamate and Ca2+. Pt-microelectrode, jointly decorated by GluOx and Pt NPs, served as an amperometric recording channel for glutamate. Meanwhile, the all-solid-state Ca2+ selective microelectrode (Ca-ISME) was employed as a potentiometric recording channel for Ca2+. The dual function microelectrode (DFME) biosensor was developed for simultaneous monitoring glutamate and Ca2+ without crosstalk between the signals. The DFME biosensor showed good selectivity towards common interferences, as well as low detection limits (0.5 μM for glutamate and 1 μM for Ca2+), which met the needs for in vivo analysis. Finally, the developed biosensor was successfully applied to real-time monitoring of glutamate and Ca2+ in live rat brain during spreading depression (SD) and ischemia processes. This study provided a simple and effective approach for in vivo analysis of two or more chemical substances.

Nucleic Acid-Functionalized Metal-Organic Framework-Based Homogeneous Electrochemical Biosensor for Simultaneous Detection of Multiple Tumor Biomarkers.

Simultaneous detection of multiple tumor biomarkers is in great demand for early and accurate cancer diagnosis. A homogeneous electrochemical biosensor has been proven to possess high sensitivity, but achieving simultaneous detection of multiple tumor biomarkers is still a challenge. Herein, we develop a novel homogeneous electrochemical biosensor for simultaneous detection of multiple tumor biomarkers based on the functionalized metal-organic frameworks (MOFs). The functionalized MOFs were prepared by using porous UIO-66-NH2 as nanocontainer to load electroactive dyes and dsDNA as a gatekeeper to cap MOFs. In this context, two functionalized MOFs (MB@UIO and TMB@UIO) were fabricated and applied to simultaneous detection of let-7a and miRNA-21, used as the proof-of-concept analytes. The recognition and hybridization of PX with target miRNAs impel the generation of RNA-DNA complexes, which separated from MOFs and allowed the electroactive dyes to be released. In comparison with the case when target miRNAs are absent, two stronger signals are recorded, and dependent on target miRNA concentrations. Thus, simultaneous detection of let-7a and minRNA-21 is achieved, with detection limits down to 3.6 and 8.2 fM, respectively, comparable or lower than those of reported strategies that concentrated on single miRNA detection. Moreover, the proposed biosensor has also been successfully applied for simultaneous detection of target miRNAs spiked in serum samples. Therefore, the proposed strategy was expected to provide more information for early and accurate cancer diagnosis and was an useful application in disease diagnosis and clinical biomedicine.

An Electrochemical Biosensor with Dual Signal Outputs: Toward Simultaneous Quantification of pH and O2 in the Brain upon Ischemia and in a Tumor during Cancer Starvation Therapy

AbstractHerein, we develop a novel method for designing electrochemical biosensors with both current and potential signal outputs for the simultaneous determination of two species in a living system. Oxygen (O2) and pH, simple and very important species, are employed as model molecules. By designing and synthesizing a new molecule, Hemin‐aminoferrocene (Hemin‐Fc), we create a single electrochemical biosensor for simultaneous detection and ratiometric quantification of O2 and pH in the brain. The reduction peak current of the hemin group increases with the concentration of O2 from 1.3 to 200.6 μm. Meanwhile, the peak potential positively shifts with decreasing pH from 8.0 to 5.5, resulting in the simultaneous determination of O2 and pH. The Fc group can serve as an internal reference for ratiometric biosensing because its current and potential signals remain almost constant with variations of O2 and pH. The developed biosensor has high temporal and spatial resolutions, as well as remarkable selectivity and accuracy, and is successfully applied in the real‐time quantification of O2 and pH in the brain upon ischemia, as well as in tumor during cancer therapy.

An Electrochemical Biosensor with Dual Signal Outputs: Toward Simultaneous Quantification of pH and O2 in the Brain upon Ischemia and in a Tumor during Cancer Starvation Therapy.

Herein, we develop a novel method for designing electrochemical biosensors with both current and potential signal outputs for the simultaneous determination of two species in a living system. Oxygen (O2 ) and pH, simple and very important species, are employed as model molecules. By designing and synthesizing a new molecule, Hemin-aminoferrocene (Hemin-Fc), we create a single electrochemical biosensor for simultaneous detection and ratiometric quantification of O2 and pH in the brain. The reduction peak current of the hemin group increases with the concentration of O2 from 1.3 to 200.6 μm. Meanwhile, the peak potential positively shifts with decreasing pH from 8.0 to 5.5, resulting in the simultaneous determination of O2 and pH. The Fc group can serve as an internal reference for ratiometric biosensing because its current and potential signals remain almost constant with variations of O2 and pH. The developed biosensor has high temporal and spatial resolutions, as well as remarkable selectivity and accuracy, and is successfully applied in the real-time quantification of O2 and pH in the brain upon ischemia, as well as in tumor during cancer therapy.

MgO nanobelt-modified graphene-tantalum wire electrode for the simultaneous determination of ascorbic acid, dopamine and uric acid

ABSTRACT A promising electrochemical biosensor for simultaneous detection of ascorbic acid (AA), dopamine (DA) and uric acid (UA) was fabricated by electrochemical deposition of MgO nanobelts on a graphene-modified tantalum wire (denoted as MgO/Gr/Ta) electrode. The MgO nanobelts and graphene were verified by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Electrochemical performances of the electrodes were characterized by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The CV results show that AA, DA and UA could be detected simultaneously using MgO/Gr/Ta electrode with peak-to-peak separation of 300 mV, 147 mV and 447 mV for AA-DA, DA-UA and AA-UA, respectively. In the threefold co-existence system, the linear calibration plots for AA, DA and UA were obtained over the concentration range of 5.0–350 μM, 0.1–7 μM and 1–70 μM with detection limits of 0.03 μM, 0.15 μM and 0.12 μM, respectively. The modified electrode shows excellent selectivity, good sensitivity and good stability, making it attractive as a sensor for simultaneous detection of AA, DA and UA in biological fluids.

Electrodeposition of platinum nanosheets on C60 decorated glassy carbon electrode as a stable electrochemical biosensor for simultaneous detection of ascorbic acid, dopamine and uric acid

ABSTRACT Platinum nanosheets (Pt NSs) were fabricated on fullerene (C 60 ) decorated glassy carbon electrode (GCE) (denoted as Pt NSs/C 60 /GCE) through a simple potentiostatic deposition method. In the coexistence of ascorbic acid (AA), dopamine (DA) and uric acid (UA), the as-prepared Pt NSs/C 60 /GCE electrode exhibited three well-resolved voltammetric peaks (Δ E AA–DA = 176 mV, Δ E DA–UA = 132 mV, Δ E AA–UA = 308 mV) in the differential pulse voltammetry (DPV) measurements, allowing a simultaneous detection of these biomolecules. There are linear relationships between current intensities and concentrations in the region of 10–1800 μM (AA), 0.5–211.5 μM (DA), and 9.5–1187 μM (UA), and the limits of detection (LOD) (S/N = 3) are down to 0.43 μM, 0.07 μM and 0.63 μM for AA, DA and UA, respectively. The as-prepared Pt NSs/C 60 /GCE electrode displayed a good reproducibility and storage stability and was successfully used for detection of AA, DA and UA in real plasma and urine samples.

A novel GMO biosensor for rapid ultrasensitive and simultaneous detection of multiple DNA components in GMO products

Since the introduction of genetically modified organisms (GMOs), there has been on-going and continuous concern and debates on the commercialization of products derived from GMOs. There is an urgent need for development of highly efficient analytical methods for rapid and high throughput screening of GMOs components, as required for appropriate labeling of GMO-derived foods, as well as for on-site inspection and import/export quarantine. In this study, we describe, for the first time, a multi-labeling based electrochemical biosensor for simultaneous detection of multiple DNA components of GMO products on the same sensing interface. Two-round signal amplification was applied by using both an exonuclease enzyme catalytic reaction and gold nanoparticle-based bio-barcode related strategies, respectively. Simultaneous multiple detections of different DNA components of GMOs were successfully achieved with satisfied sensitivity using this electrochemical biosensor. Furthermore, the robustness and effectiveness of the proposed approach was successfully demonstrated by application to various GMO products, including locally obtained and confirmed commercial GMO seeds and transgenetic plants. The proposed electrochemical biosensor demonstrated unique merits that promise to gain more interest in its use for rapid and on-site simultaneous multiple screening of different components of GMO products.

Novel Electrochemical Biosensor for Simultaneous Detection of Adenine and Guanine Based on Cu2O Nanoparticles

In this paper Cu2O nanoparticles were prepared and used for the construction of novel electrochemical voltammetric biosensor for the simultaneous detection of adenine and guanine. Cu2O nanoparticles were synthesized via simple wet chemical route, where glucose was used as a reductant. The nanoparticles were characterized by SEM and XRD analysis, which showed the presence of spherical aggregations with diameter of 1000 nm. These nanoparticles were successfully used for fabrication of spray-coated and screen-printed working electrodes on alumina substrate for the electrochemical detection of purine bases. We observed that Cu(I) reacts with adenine to form insoluble complex that accumulates on the electrode surface and causes the decrease of current response. In the case of guanine, we did not observed any significant decrease of current response which is probably caused by adsorption of guanine on the electrode surface.