A novel and ultrasensitive sandwich-type electrochemical immunosensor based on delaminated MXene@AuNPs as signal amplification for prostate specific antigen (PSA) detection and immunosensor validation.
TL;DR: An ultra-sensitive electrochemical immunosensor for PSA detection was designed and self-assembled delaminated MXene-gold nanoparticles was used to label PSA seconder antibody2 (Ab2) as signal amplification.
About: This article is published in Talanta.The article was published on 2020-12-01. It has received 56 citations till now. The article focuses on the topics: Cyclic voltammetry.
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TL;DR: In this paper, a label-free electrochemical biosensor was presented as a powerful nanobiodevice for SARS-CoV-2 spike protein detection, which was applied on a screen-printed carbon electrode modified with Cu2O nanocubes (Cu2O NCs), which provided a large surface area in a very small space.
Abstract: Severe acute respiratory syndrome SARS-CoV-2 has caused a global pandemic starting in 2020. Accordingly, testing is crucial for mitigating the economic and public health effects. In order to facilitate point-of-care diagnosis, this study aims at presenting a label-free electrochemical biosensor as a powerful nanobiodevice for SARS-CoV-2 spike protein detection. Utilizing the IgG anti-SARS-CoV-2 spike antibody onto the electrode surface as a specific platform in an ordered orientation through staphylococcal protein A (ProtA) is highly significant in fabricating the designed nanobiodevice. In this sense, the screen-printed carbon electrode modified with Cu2O nanocubes (Cu2O NCs), which provide a large surface area in a very small space, was applied in order to increase the ProtA loading on the electrode surface. Accordingly, the sensitivity and stability of the sensing platform significantly increased. The electrochemical evaluations proved that there is a very good linear relationship between the charge transfer resistance (Rct) and spike protein contents via a specific binding reaction in the range 0.25 fg mL−1 to 1 μg mL−1. Moreover, the assay when tested with influenza viruses 1 and 2 was performed in 20 min with a low detection limit of 0.04 fg mL−1 for spike protein without any cross-reactivity. The designed nanobiodevice exhibited an average satisfactory recovery rate of ~ 97–103% in different artificial sample matrices, i.e., saliva, artificial nasal, and universal transport medium (UTM), illustrating its high detection performance and practicability. The nanobiodevice was also tested using real patients and healthy samples, where the results had been already obtained using the standard polymerase chain reaction (PCR) procedure, and showed satisfactory results.
83 citations
TL;DR: A sandwich-type sensitive voltammetric immunosensor for breast cancer biomarker human epidermal growth factor receptor 2 (HER2) detection was prepared as mentioned in this paper, which showed high selectivity, stability, reproducibility, and reusability.
Abstract: A sandwich-type sensitive voltammetric immunosensor for breast cancer biomarker human epidermal growth factor receptor 2 (HER2) detection was prepared The electrochemical immunosensor was developed based on gold nanoparticles decorated copper-organic framework (AuNPs/Cu-MOF) and quaternary chalcogenide with platinum-doped graphitic carbon nitride (g-C3N4) Cu2ZnSnS4 nanoparticle (CZTS NP) quaternary chalcogenide with platinum (Pt)-doped g-C3N4 composite (Pt/g-C3N4) was tagged as CZTS NPs/Pt/g-C3N4 AuNPs/Cu-MOF composite was successfully synthesized by amidation reaction between AuNPs functionalized with amino group and Cu-MOFs containing carboxylic acid After the conjugations of primer HER2 antibody and antigen HER2 protein to AuNPs/Cu-MOF as sensor platform, CZTS NPs/Pt/g-C3N4 composite was prepared by one-pot hydrothermal method After immune reaction of 30 min, the prepared HER2 immunosensor was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD) method, x-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) The developed immunosensor showed high sensitivity with a detection limit of 300 fg mL−1 Additional properties of the voltammetric immunosensor are high selectivity, stability, reproducibility, and reusability
65 citations
56 citations
TL;DR: In this article, a hybrid electrochemical sensor with electrospun one-dimensional MnMoO4 nanofibers coupled with a few-layered exfoliated two-dimensional MXene was proposed.
44 citations
TL;DR: In this paper, the authors classified various electrochemical based techniques of Ochratoxin A (OTA) determination creatively into Impedimetric, Voltammetric, Amperometric and Electrochemiluminescence assays and their efficient comparison with conventional, and clinical methods including Capillary Electrophoresis (CE), HPLC, Liquid Chromatography/Mass Spectroscopy (LC/MS), and Enzyme Linked Immunosorbent Assay (ELISA) has been performed comprehensively.
39 citations
References
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TL;DR: 2D nanosheets, composed of a few Ti 3 C 2 layers and conical scrolls, produced by the room temperature exfoliation of Ti 3 AlC 2 in hydrofl uoric acid are reported, which opens a door to the synthesis of a large number of other 2D crystals.
Abstract: Currently, however, there are relatively few such atomically layered solids. [ 2–5 ] Here, we report on 2D nanosheets, composed of a few Ti 3 C 2 layers and conical scrolls, produced by the room temperature exfoliation of Ti 3 AlC 2 in hydrofl uoric acid. The large elastic moduli predicted by ab initio simulation, and the possibility of varying their surface chemistries (herein they are terminated by hydroxyl and/or fl uorine groups) render these nanosheets attractive as polymer composite fi llers. Theory also predicts that their bandgap can be tuned by varying their surface terminations. The good conductivity and ductility of the treated powders suggest uses in Li-ion batteries, pseudocapacitors, and other electronic applications. Since Ti 3 AlC 2 is a member of a 60 + group of layered ternary carbides and nitrides known as the MAX phases, this discovery opens a door to the synthesis of a large number of other 2D crystals. Arguably the most studied freestanding 2D material is graphene, which was produced by mechanical exfoliation into single-layers in 2004. [ 1 ] Some other layered materials, such as hexagonal BN, [ 2 ] transition metal oxides, and hydroxides, [ 4 ] as well as clays, [ 3 ] have also been exfoliated into 2D sheets. Interestingly, exfoliated MoS 2 single layers were reported as early as in 1986. [ 5 ] Graphene is fi nding its way to applications ranging from supercapacitor electrodes [ 6 ] to reinforcement in composites. [ 7 ] Although graphene has attracted more attention than all other 2D materials combined, its simple chemistry and the weak van der Waals bonding between layers in multilayer structures limit its use. Complex, layered structures that contain more than one element may offer new properties because they
6,846 citations
TL;DR: This capacitance report reports a method of producing two-dimensional titanium carbide ‘clay’ using a solution of lithium fluoride and hydrochloric acid that offers a much faster route to film production as well as the avoidance of handling hazardous concentrated hydrofluoric acid.
Abstract: Safe and powerful energy storage devices are becoming increasingly important. Charging times of seconds to minutes, with power densities exceeding those of batteries, can in principle be provided by electrochemical capacitors--in particular, pseudocapacitors. Recent research has focused mainly on improving the gravimetric performance of the electrodes of such systems, but for portable electronics and vehicles volume is at a premium. The best volumetric capacitances of carbon-based electrodes are around 300 farads per cubic centimetre; hydrated ruthenium oxide can reach capacitances of 1,000 to 1,500 farads per cubic centimetre with great cyclability, but only in thin films. Recently, electrodes made of two-dimensional titanium carbide (Ti3C2, a member of the 'MXene' family), produced by etching aluminium from titanium aluminium carbide (Ti3AlC2, a 'MAX' phase) in concentrated hydrofluoric acid, have been shown to have volumetric capacitances of over 300 farads per cubic centimetre. Here we report a method of producing this material using a solution of lithium fluoride and hydrochloric acid. The resulting hydrophilic material swells in volume when hydrated, and can be shaped like clay and dried into a highly conductive solid or rolled into films tens of micrometres thick. Additive-free films of this titanium carbide 'clay' have volumetric capacitances of up to 900 farads per cubic centimetre, with excellent cyclability and rate performances. This capacitance is almost twice that of our previous report, and our synthetic method also offers a much faster route to film production as well as the avoidance of handling hazardous concentrated hydrofluoric acid.
3,783 citations
TL;DR: This review discusses various nanomaterials that have been explored to mimic different kinds of enzymes and covers their kinetics, mechanisms and applications in numerous fields, from biosensing and immunoassays, to stem cell growth and pollutant removal.
Abstract: Over the past few decades, researchers have established artificial enzymes as highly stable and low-cost alternatives to natural enzymes in a wide range of applications. A variety of materials including cyclodextrins, metal complexes, porphyrins, polymers, dendrimers and biomolecules have been extensively explored to mimic the structures and functions of naturally occurring enzymes. Recently, some nanomaterials have been found to exhibit unexpected enzyme-like activities, and great advances have been made in this area due to the tremendous progress in nano-research and the unique characteristics of nanomaterials. To highlight the progress in the field of nanomaterial-based artificial enzymes (nanozymes), this review discusses various nanomaterials that have been explored to mimic different kinds of enzymes. We cover their kinetics, mechanisms and applications in numerous fields, from biosensing and immunoassays, to stem cell growth and pollutant removal. We also summarize several approaches to tune the activities of nanozymes. Finally, we make comparisons between nanozymes and other catalytic materials (other artificial enzymes, natural enzymes, organic catalysts and nanomaterial-based catalysts) and address the current challenges and future directions (302 references).
2,951 citations
TL;DR: This work proposes to comprehensively review the recent advances in molecular imprinting including versatile perspectives and applications, concerning novel preparation technologies and strategies of MIT, and highlight the applications of MIPs.
Abstract: Molecular imprinting technology (MIT), often described as a method of making a molecular lock to match a molecular key, is a technique for the creation of molecularly imprinted polymers (MIPs) with tailor-made binding sites complementary to the template molecules in shape, size and functional groups. Owing to their unique features of structure predictability, recognition specificity and application universality, MIPs have found a wide range of applications in various fields. Herein, we propose to comprehensively review the recent advances in molecular imprinting including versatile perspectives and applications, concerning novel preparation technologies and strategies of MIT, and highlight the applications of MIPs. The fundamentals of MIPs involving essential elements, preparation procedures and characterization methods are briefly outlined. Smart MIT for MIPs is especially highlighted including ingenious MIT (surface imprinting, nanoimprinting, etc.), special strategies of MIT (dummy imprinting, segment imprinting, etc.) and stimuli-responsive MIT (single/dual/multi-responsive technology). By virtue of smart MIT, new formatted MIPs gain popularity for versatile applications, including sample pretreatment/chromatographic separation (solid phase extraction, monolithic column chromatography, etc.) and chemical/biological sensing (electrochemical sensing, fluorescence sensing, etc.). Finally, we propose the remaining challenges and future perspectives to accelerate the development of MIT, and to utilize it for further developing versatile MIPs with a wide range of applications (650 references).
1,647 citations
TL;DR: PCa incidence rates increased in nearly all countries considered in this analysis except in a few high-income countries, and the increase in PCa mortality rates mainly occurred in lower resource settings, with declines largely confined to high-resource countries.
1,362 citations