-
1.
Experimental and theoretical study for miR-155 detection through resveratrol interaction with nucleic acids using magnetic core-shell nanoparticles.
Yazdanparast, S, Benvidi, A, Azimzadeh, M, Tezerjani, MD, Ghaani, MR
Mikrochimica acta. 2020;(8):479
Abstract
A novel electrochemical nanobiosensor for the detection of miR-155 (as breast cancer biomarker) is introduced . Fe3O4NPs@Ag core-shell nanoparticles were synthesized and their shape and characteristics were confirmed by scanning electron microscope (SEM) imaging, Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) methods. Synthesized nanoparticles were applied onto the magnetic bar carbon paste electrode and then the amine-modified anti-miR-155 (single-stranded probes) was applied on the modified electrode surface and upon hybridization with target miR-155, resveratrol (RSV) was eventually applied as an electrochemical label on the double-strand oligonucleotide. Differential pulse voltammetry (DPV) of the oxidation peak of RSV was assumed as the final signal by sweeping potential from 0 to 0.6 V (vs. Ag/AgCl). The fabrication process was optimized through a series of experiments and the optimized process was confirmed using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The linear range of the fabricated nanobiosensor was 0.5 fM to 1.0 nM and the detection limit was 0.15 fM. The nanobiosensor was able to pass reproducibility and specificity tests using different types of mismatched target sequences.Spiked real samples of human serum were used to confirm that the nanobiosensor enables detection of miR-155 without any significant interferences from other moieties and molecules. Finally, the molecular dynamics simulation of the RSV interaction with single- and double-stranded oligonucleotide was performed and confirmed the preferential binding of RSV to double-stranded DNA; therefore, it can be used as the electrochemical label of DNA and/or miRNA hybridization-based biosensors. Graphical abstract.
-
2.
A Review on Electrochemical Sensors and Biosensors Used in Phenylalanine Electroanalysis.
Dinu, A, Apetrei, C
Sensors (Basel, Switzerland). 2020;(9)
Abstract
Phenylalanine is an amino acid found in breast milk and in many foods, being an essential nutrient. This amino acid is very important for the human body because it is transformed into tyrosine and, subsequently, into catecholamine neurotransmitters. However, there are individuals who were born with a genetic disorder called phenylketonuria. The accumulation of phenylalanine and of some metabolites in the body is dangerous and may cause convulsions, brain damage and mental retardation. Determining the concentration of phenylalanine in different biologic fluids is very important because it can provide information about the health status of the individuals envisaged. Since such determinations may be made by using electrochemical sensors and biosensors, numerous researchers have developed such sensors for phenylalanine detection and different sensitive materials were used in order to improve the selectivity, sensitivity and detection limit. The present review aims at presenting the design and performance of some electrochemical bio (sensors) traditionally used for phenylalanine detection as reported in a series of relevant scientific papers published in the last decade.
-
3.
Recognition and sensitive detection of CTCs using a controllable label-free electrochemical cytosensor.
Zhang, H, Liang, F, Wu, X, Liu, Y, Chen, A
Mikrochimica acta. 2020;(9):487
Abstract
An excellent atomic layer deposition (ALD) method was adopted for the controllable systhesis of a xFe2O3-nPt (or nPt-xFe2O3)-coated graphene nanostructure (xFe2O3-nPt@graphene). The produced nanomaterials have been characterized by transmission electron microscopy (TEM), cyclic voltammetry (CV), and X-ray photoelectron spectroscopy (XPS). It is shown that xFe2O3 and nPt were effectively tailored and deposited on the graphene. A simple, rapid, and sensitive electrochemical cytosensor based on the controllable nanomaterials was successfully developed for MCF-7 cells detection by combining the high affinity and specificity of an aptamer. The prepared cytosensor displays a linear response to MCF-7 in the concentration range 18 to 1.5 × 106 cell mL-1 with the detection limit of 6 cell mL-1 (at an S/N of 3). This cytosensor was applied to detect circulating tumor cells (CTCs) in patient blood and the results were satisfied. The experimental results indicate that the proposed controllable electrochemical cytosensor is highly-sensitive, and convenient for clinical detection of breast CTCs. Graphical abstract.
-
4.
Mechanical Tolerance of Cascade Bioreactions via Adaptive Curvature Engineering for Epidermal Bioelectronics.
Wang, T, Lei, QL, Wang, M, Deng, G, Yang, L, Liu, X, Li, C, Wang, Q, Liu, Z, Wang, J, et al
Advanced materials (Deerfield Beach, Fla.). 2020;(22):e2000991
Abstract
Epidermal bioelectronics that can monitor human health status non-invasively and in real time are core to wearable healthcare equipment. Achieving mechanically tolerant surface bioreactions that convert biochemical information to detectable signals is crucial for obtaining high sensing fidelity. In this work, by combining simulations and experiments, a typical epidermal biosensor system is investigated based on a redox enzyme cascade reaction (RECR) comprising glucose oxidase/lactate oxidase enzymes and Prussian blue nanoparticles. Simulations reveal that strain-induced change in surface reactant flux is the key to the performance drop in traditional flat bioelectrodes. In contrast, wavy bioelectrodes capable of curvature adaptation maintain the reactant flux under strain, which preserves sensing fidelity. This rationale is experimentally proven by bioelectrodes with flat/wavy geometry under both static strain and dynamic stretching. When exposed to 50% strain, the signal fluctuations for wavy bioelectrodes are only 7.0% (4.9%) in detecting glucose (lactate), which are significantly lower than the 40.3% (51.8%) in flat bioelectrodes. Based on this wavy bioelectrode, a stable human epidermal metabolite biosensor insensitive to human gestures is further demonstrated. This mechanically tolerant biosensor based on adaptive curvature engineering provides a reliable bio/chemical-information monitoring platform for soft healthcare bioelectronics.
-
5.
Construction of Molecular Sensing and Logic Systems Based on Site-Occupying Effect-Modulated MOF-DNA Interaction.
Yu, K, Wei, T, Li, Z, Li, J, Wang, Z, Dai, Z
Journal of the American Chemical Society. 2020;(51):21267-21271
Abstract
Interactions between metal-organic frameworks (MOFs) and nucleic acids are of great importance in molecular assembly. However, current MOF-nucleic acid interactions lack diversity and are normally realized in an uncontrollable manner. Herein, the interaction of zirconium-based MOFs (Zr-MOFs) with nucleic acids is enabled by the formation of Zr-O-P bonds and further manipulated by a phosphate-induced site-occupying effect. Covering Zr ions in clusters of MOFs with phosphates impedes the formation of Zr-O-P bonds with nucleic acids, rendering the MOF-nucleic acid interaction tunable and stimulus-responsive. Notably, the experimental results demonstrate that various phosphates, Zr-MOFs, and nucleic acids can all be adopted in the tunable interaction. On the basis of these findings, fluorescent DNA and typical Zr-MOFs are proposed as functional probe-quencher pairs to establish molecular sensing and logic systems. Accordingly, alkaline phosphatase and inorganic pyrophosphatase can be quantified simultaneously, and the overall relation of different phosphates and phosphatases is facilely displayed. The work provides a general strategy for modulating MOF-nucleic acid interactions, which is conducive to the development of molecular intelligent systems.
-
6.
Considering the Effects of Microbiome and Diet on SARS-CoV-2 Infection: Nanotechnology Roles.
Kalantar-Zadeh, K, Ward, SA, Kalantar-Zadeh, K, El-Omar, EM
ACS nano. 2020;(5):5179-5182
Abstract
The impact of dietary patterns and the commensal microbiome on susceptibility to and severity of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has been largely ignored to date. In this Perspective, we present a rationale for an urgent need to investigate this possible impact and therapeutic options for COVID-19 based on dietary and microbiome modifications. The mitigating role of nanotechnology with relation to the impact of SARS-CoV-2 virus is highlighted.
-
7.
Ultrasensitive electrochemical genosensor for detection of CaMV35S gene with Fe3O4-Au@Ag nanoprobe.
Ye, Y, Mao, S, He, S, Xu, X, Cao, X, Wei, Z, Gunasekaran, S
Talanta. 2020;:120205
Abstract
We report an attomolar sensitive electrochemical genosensor for the detection of cauliflower mosaic virus 35S (CaMV35S) gene. The sandwich-type genosensor uses gold-silver core-shell (Au@Ag)-loaded iron oxide (Fe3O4) nanocomposite (Fe3O4-Au@Ag) as label of signal DNA probe (sDNA). Electrochemical sensing is accomplished at interface of electrodeposited AuNPs and carboxylated multiwalled carbon nanotubes-modified glassy carbon electrode through the specific interaction between the capture probe and target CaMV35S (tDNA), and tDNA and the labeled sDNA. The detection sensitivity was improved by the amplified reduction signal of hydrogen peroxide (H2O2), which takes advantage of the enhanced electrocatalytic activity of Fe3O4-Au@Ag. Under the optimal experimental conditions, an ultralow limit of detection was calculated to be 1.26 × 10-17 M (S/N = 3), and the blank value subtracted reduction signal of H2O2 of the sensor increased linearly with the logarithm of CaMV35S concentration over a wide range (1 × 10-16 M to 1 × 10-10 M). This genosensor displayed excellent stability, selectivity and reproducibility, and was successful in detecting the target CaMV35S in genetically modified tomato samples.
-
8.
Assay of Phospholipase D Activity by an Amperometric Choline Oxidase Biosensor.
Ciriello, R, Guerrieri, A
Sensors (Basel, Switzerland). 2020;(5)
Abstract
A novel electrochemical method to assay phospholipase D (PLD) activity is proposed based on the employment of a choline biosensor realized by immobilizing choline oxidase through co-crosslinking on an overoxidized polypyrrole film previously deposited on a platinum electrode. To perform the assay, an aliquot of a PLD standard solution is typically added to borate buffer containing phosphatidylcholine at a certain concentration and the oxidation current of hydrogen peroxide is then measured at the rotating modified electrode by applying a detection potential of + 0.7 V vs. SCE. Various experimental parameters influencing the assay were studied and optimized. The employment of 0.75% (v/v) Triton X-100, 0.2 mM calcium chloride, 5 mM phosphatidylcholine, and borate buffer at pH 8.0, ionic strength (I) 0.05 M allowed to achieve considerable current responses. In order to assure a controlled mass transport and, at the same time, high sensitivity, an electrode rotation rate of 200 rpm was selected. The proposed method showed a sensitivity of 24 (nA/s)(IU/mL)-1, a wide linear range up to 0.33 IU/mL, fast response time and appreciable long-term stability. The limit of detection, evaluated from the linear calibration curve, was 0.005 IU/mL (S/N = 3). Finally, due to the presence of overoxidized polypyrrole film characterized by notable rejection properties towards electroactive compounds, a practical application to real sample analysis can be envisaged.
-
9.
Electrochemical determination of zearalenone using a label-free competitive aptasensor.
Azri, FA, Eissa, S, Zourob, M, Chinnappan, R, Sukor, R, Yusof, NA, Raston, NHA, Alhoshani, A, Jinap, S
Mikrochimica acta. 2020;(5):266
Abstract
An electrochemical aptasensor is described for determination of the phytohormone of zearalenone (ZEA). The gold electrode was modified with ZEA via covalent attachment using cysteamine-hydrochloride and 1,4-phenylene diisocyanate linker. A truncated ZEA aptamer with a dissociation constant of 13.4 ± 2.1 nM was used in an aptasensor. The electrochemical property was investigated using square wave voltammetry for monitoring the change in the electron transfer using the ferro/ferricyanide system as redox probe. Under optimal experimental conditions, the response was best measured at a potential of 0.20 V (vs. Ag/AgCl). The signals depended on the competitive mechanism between the immobilised ZEA and free ZEA for the aptamer binding site. The aptasensor works in the range 0.01 to 1000 ng·mL-1 ZEA concentration, with a detection limit of 0.017 ng·mL-1. High degree of cross-reactivity with the other analogues of ZEA was observed, whereas none towards other mycotoxins. The aptasensor was further applied for the determination of ZEA in the extract of maize grain and showed good recovery percentages between 87 and 110%. Graphical abstract Schematic representation of the electrochemical determination of zearalenone based on indirect competitive assay. Step a Immobilisation of ZEA on the surface of gold electrode via covalent attachment, b competition for the ZEA aptamer binding site between immobilised and free ZEA, and c current signal of the binding event based on SWV technique.
-
10.
What biologists want from their chloride reporters - a conversation between chemists and biologists.
Zajac, M, Chakraborty, K, Saha, S, Mahadevan, V, Infield, DT, Accardi, A, Qiu, Z, Krishnan, Y
Journal of cell science. 2020;(2)
Abstract
Impaired chloride transport affects diverse processes ranging from neuron excitability to water secretion, which underlie epilepsy and cystic fibrosis, respectively. The ability to image chloride fluxes with fluorescent probes has been essential for the investigation of the roles of chloride channels and transporters in health and disease. Therefore, developing effective fluorescent chloride reporters is critical to characterizing chloride transporters and discovering new ones. However, each chloride channel or transporter has a unique functional context that demands a suite of chloride probes with appropriate sensing characteristics. This Review seeks to juxtapose the biology of chloride transport with the chemistries underlying chloride sensors by exploring the various biological roles of chloride and highlighting the insights delivered by studies using chloride reporters. We then delineate the evolution of small-molecule sensors and genetically encoded chloride reporters. Finally, we analyze discussions with chloride biologists to identify the advantages and limitations of sensors in each biological context, as well as to recognize the key design challenges that must be overcome for developing the next generation of chloride sensors.