Sensors For Biomolecules Research Articles

In-situ electrochemical synthesis of Ni/Ni(OH)2/molecularly imprinted polymer nanocomposite for high-performance glucose detection

This study presents a novel non-enzymatic glucose sensor that synergistically combines the high catalytic activity of nickel hydroxide (Ni(OH)2) with the selective recognition of molecularly imprinted polymers (MIPs). The sensors were fabricated through an entirely in-situ synthesis directly on the electrode, comprising electrodeposition and oxidation of Ni/Ni(OH)2 nanoparticles and electropolymerization of a glucose-imprinted MIP layer using pyrrole and 3-aminophenyl boronic acid. The integrated MIP layer significantly enhanced selectivity against common interferents while amplifying glucose sensitivity. The resulting sensor demonstrated a high sensitivity of 1802 μA mM−1 cm−2 with a linear range from 0.04 to 2.6 mM. Notably, the sensor exhibited remarkable stability, retaining 97.2 % of its original sensitivity after 6 months of room-temperature storage. To extend the linear range, Nafion coatings at two concentrations were applied, achieving ranges up to 0.04–11.6 mM with adjusted sensitivities. This innovative approach, leveraging MIPs to provide selectivity to electrocatalytic nanomaterials, offers a promising strategy for developing high-performance non-enzymatic sensors for glucose and other biomolecules in diabetes monitoring and beyond.

Tuning the Optical Anisotropy in Gradient Porous Germanium on Si Substrate

AbstractPorous semiconductors have garnered significant attention owing to their distinctive physical and chemical properties. In this study, optical anisotropy is presented in porous germanium (PGe) on a Si (001) substrate. Both n‐ and p‐type PGe, achieved through bipolar electrochemical etching, exhibit optical anisotropy along the Ge <001> direction, as determined by spectroscopic ellipsometry. Birefringence and depolarization factors are controllable by adjusting the etching parameters and doping concentration of the epitaxial Ge layer. The gradient porosity and pore distribution in PGe can be well captured by the optical models. The findings of optical anisotropy in PGe‐on‐Si hold promise for applications in optical elements or sensors for gas or biomolecules.

Small amine-functionalized diesel soot-derived onion-like nanocarbon for selective sensing of glutamic acid and imaging application

Amine functionalized online like nanocarbon utilized in biological applications as a biomolecule sensor and imaging agent.

Effect of biaxial strain and vacancy defects in 2D MoS2 monolayer for the sensing of nitrobenzene: A DFT investigation

Considering the increased release of toxic nitrobenzene (NB) molecules into the atmosphere, proposing a sensor material that could effectively remove it from the environment is essential. In this regard, we have investigated the NB adsorption performance of vacancy-defected (S, Mo and di S) and biaxially strained (−4 % to 4 %) MoS2 monolayers through density functional theory (DFT) simulations. Applying biaxial (tensile and compression) strain to the monolayer significantly increased the adsorption energy and charge transfer to −1.02 eV and 0.09 e, respectively, much greater than in the pristine case. The formation energy calculations verified the stability of (S, Mo, 2S) vacancy-defected MoS2 monolayer. The low formation energy of 3.3 eV suggests the ease of formation of MoS2 monolayer with single S vacancy. Introducing defects and strain improved the conductivity of the monolayer, thereby increasing the NB adsorption ability. The reasonable NB adsorption energy on the modified monolayer was due to the accelerated charge transfer and orbital interaction between the valence S 3p orbitals of MoS2 and 2p orbitals of O in NB. The recovery time of the strained and defective monolayers is the order of only a few seconds at 400 K, which is quite attainable. Therefore, this work put forth a more effective to improve the NB performance of the monolayer and can be a motivation for the further development of high-performance biomolecule sensors.

Evaluating ammonia sensors based on two-dimensional pure and silicon-decorated biphenylene using DFT calculations

Within this piece of research, the performance of two-dimensional pure and silicon-decorated monolayers of biphenylene (PBPML and SBPML) in detecting ammonia (NH3) was investigated though DFT calculations. In spite of the fact that PBPML adsorbed NH3 better than other reported 2D materials, NH3 had a physical adhesion on the surface of PBPML and the adhesion energy was −0.037 eV. After decorating the Si atom, the NH3 adhesion capacity of PBPML changed significantly and there was a dramatic change in its electronic attributes. The SBPML can be considered as an encouraging sensor for NH3 with a structural solidity at ambient temperatures, the recovery time of 0.84 s at 300 K, charge transport of 0.56 e and significant adhesion energy of −0.72 eV. The results demonstrated that the SBPML was suitable for sensing NH3 and it was suitable for practical applications. This work can provide insights into the designing and development of biomolecule sensors with high efficiency.

Polyethylene Glycol (PEG) Coated Magnetite Nanoparticles Prepared by Sol-Gel Method for Biotechnology Applications

Polyethylene glycol (PEG) coatings are developed for magnetite nanoparticles (NPs). The magnetic properties of superparamagnetic type, magnetite Fe3O4 nanoparticles are suitable for biosensing applications. Magnetic NPs were prepared by Co-precipitation method and oven dried. Using a Transmission Electron Microscope (TEM) and X-Ray Diffractometer (XRD), nanoparticles size and composition were found, including the presence of Fe3O4 peak. The magnetic properties are influenced by electron environments of the Fe3+ ions within the iron oxide structure. The magnetic properties were measured by Vibrating Sample Magnetometer (VSM), thus, the results of Fe3O4 NPs exhibited a high magnetic saturation (Ms) of 61.31 emu/g. In the case of PEG coated MNPs, confirmed by Fourier Transform Infrared Spectroscopy (FT-IR), a reduced Ms of 40.00 emu/g, which decreased further following surface modification with 3-aminopropyl triethoxysilane (NH2) to 36.77 emu/g. The resulting size range of NPs of pure Fe3O4 NPs was 5-50 nm. In comparison, the PEG coated NPs were larger, 10-100 nm. In the part of protein binding and separation from solutions of bovine serum albumin (BSA) where investigated. This process will be beneficial to developing low cost sensors for biomolecules and biotechnologies in the future.

“Turn-on” fluorescence sensing of cardiac troponin I based on MnO2 nanosheet quenched mercaptopropionic acid capped Mn2+ doped zinc sulphide quantum dots

Acute Myocardial Infarction (AMI) is the persisting serious threat among all cardiovascular diseases due to its highest mortality rates. Clinicians resort to biomarker levels pertinent to AMI in triaging patients. Among the several cardiac biomarkers, by virtue of the specificity and sensitivity, cardiac troponin I (cTnI) was recognized as the gold standard for AMI diagnosis. Immunosensors that have been developed for cTnI detection are limited by multistep process and long diagnostic time which makes them unadaptable in primary healthcare centres. Recently, Fluorescence Resonance Energy Transfer (FRET) based immunosensors have found wide applicability in biomolecule detection. Among the evolving nanomaterials, Quantum dots (QDs) have been emerged as attractive donors in FRET based sensors for biomolecules. In the present work, we report a simple and sensitive fluorescence immunosensor for cTnI detection using Mercaptopropionic acid (MPA) capped Mn2+ doped ZnS QDs and MnO2 nanosheet as the FRET couple. For the specific detection of cTnI antigen, we have coupled cTnI antibody on the surface of MPA capped Mn2+ doped ZnS QDs. cTnI can be detected linearly with a low Limit of Detection (LoD) of 0.05 ng/mL. Furthermore, the selectivity of the developed probe has also been evaluated in the presence of other potential interferants and other cardiac biomarkers. In real serum samples, good recovery percentage was obtained proving that the probe is adaptable for Point of care detection of cTnI.

Enhanced nitrobenzene sensing in metal anchored gamma-graphyne: predictions from density functional theory

Nitrobenzene (NB), being a toxic industrial effluent, its adsorption performance on pristine and metals (Al, Cu and Sc) anchored 2D graphyne (GY) monolayer was studied systematically via the first principles DFT simulations. The NB was found to be weakly adsorbed on the pristine monolayer with an energy of −0.46 eV due to the long-range van der Waals interactions. The NB was strongly adsorbed on the anchored metal site except for the case of Cu. The adsorption energy calculations suggest that the Al-anchored GY monolayer is excellent for the NB sensing because of the reasonable adsorption energy of −1.18 eV, charge transfer of 0.57 e and attainable recovery time of 2.4 s at 450 K. The work function sensitivity of the Al anchored system towards the NB molecule is 10% higher than the pristine system. Moreover, the ab-initio molecular dynamics simulations have predicted the room temperature structural steadiness of the Al-anchored GY monolayer. Overall, our research suggests that the Al-anchored GY monolayer is promising to adsorb the NB molecules effectively and can be potentially applied as an excellent NB biomolecule sensor.

Study of ZnO nanoparticle-supported clay minerals for electrochemical sensors, photocatalysis, and antioxidant applications

In view of the current study's demonstration of the synthesis of clay-doped ZnO composites, we present a low-cost method for producing clay-metal oxide (clay/ZnO). Utilizing the solution combustion technique, a composite of clay/ZnO was produced utilizing citric acid as both a fuel and a complexing agent. The hexagonal unit cell structure of the created clay/ZnO may be seen using XRD patterns. The ZnO-infused clay was visible in FE-SEM micrographs as homogenous, sphere-shaped ZnO. The possible involvement of clay/ZnO photocatalytic activity in the UV-induced photodegradation of malachite green dye was investigated. The 90% degradation rate shows the composite's outstanding photocatalytic degradation capacity. The resulting substance was electrochemically analyzed using a constructed electrode in 0.1 M KOH electrolyte. It increased its sensor capabilities, which now include chemical and biomolecule sensors, and it excelled in cyclic voltammetry-based redox potential studies. To efficiently evaluate chemically synthesized NPs for electrochemical, sensing, and photocatalytic applications, this study intends to create a solution combustion procedure for the synthesis of clay/ZnO nanocomposite using urea as fuel.

C24 Fullerene and its derivatives as a viable glucose sensor: DFT and TD-DFT studies

The requirement of highly sensitive, selective and responsive sensor for biomolecules remains a subject of great interest and under the development. We aimed to explore new 0D materials such as C24, Al12N12 and Al12P12 fullerenes for glucose sensing using dispersion (D3) corrected Density functional calculation with B3LYP/6–31G(d,p) basis sets. Among these Al12P12 and Al12N12 show the strong chemisorption and charge is transferred from fullerenes to Glucose(Glu) while an optimal adsorption has been found for C24 with glucose in which charge is transferred from glucose to fullerene. Adsorption energy calculation, NBO analysis, Mulliken charge analysis, DOS calculation, RDG analysis, sensing response and UV spectra analysis have been performed to justify the interaction between glucose and C24 and their derivatives. All calculations favor our expected results and concludes that for Al12N12 and Al12P12 can be used for glucose isolation from mixture of the other biomolecules due to their high recovery time in range of 1019 and 1011 s while C24 as a detection purpose. Based on the Mulliken charge analysis it has been observed that charge have been transferred from Glucose to Al12N12 and Al12P12. On the effect of water solvent, it is observed that the nature of the adsorption for Al12N12 and Al12P12 towards glucose remains the same and it confirms their application as carrier.

Sensitive MIM plasmonic biosensors for detection of hemoglobin, creatinine and cholesterol concentrations

In this paper, a nano structure based on graphene-plasmonic/black phosphorous combination is proposed and investigated. The main goal of the presented work is detection of different biological elements in blood samples. The structure is consisted of different layers of Ag (silver), air, graphene and black phosphorous. Various layers are considered in the T-shaped, U-shaped and split ring-shaped waveguides. The incident field would be applied to the T-shaped waveguide and output signals would be transmitted to the three output ports (output1, output2 and output3). The structure is supposed to function as sensitive bio-sensors. Therefore, effects of different structural parameters (r2, t2, r3, t3, r4, t4), chemical potentials (μc2, μc3, μc4) and black phosphorous layers on the transmission spectrum of output ports are considered. These processes lead to improved transmission's peak value and wavelength (enhancing sensor's functionalities). Finally, the improved structure would be considered as refractive index sensors. Cholesterol, Creatinine and Hemoglobin concentrations in blood samples would be diagnosed at ouput1, output2 and output3 ports, respectively. Considerable sensitivity factors of 5333.3[nm/RIU], 1562.5[nm/RIU] and 800[nm/RIU] are obtained for Cholesterol, Creatinine and Hemoglobin concentrations, respectively. Other important parameters (figure of merit, quality factor and limit of detection) are also calculated for each biomolecule sensor. Considering these sensitivity factors, the structure can be utilized as accurate bio-sensors in optical integrated circuits.

Numerical analysis of hafnium oxide and phase change material-based multi-layered infrared and visible frequency sensor for biomolecules sensing application

We report on the results of a numerical investigation into a phase transition material and hafnium (IV) oxide-based refractive index sensor with a wide spectral range, including both the visible and infrared regions of the electromagnetic spectrum. The sensor relies on hafnium (IV) oxide and a phase transition material (HfO2). Three layered versions of the proposed structure are studied; each configuration is built from alternating layers of HfO2, silica, Ge2Sb2Te5(GST), and silver. The three different arrangements have all been studied. The reflectance response of such multilayer structures is discussed in this manuscript for refractive indices ranging from 1 to 2.4. In addition, we have investigated how the varying heights of the materials affect the overall performance of the structure. Finally, we have supplied several formulae for resonating traces that may be used to calculate the sensing behaviour across a specific wavelength range and refractive index values. The corresponding equations are shown below. We have computed numerous equation traces throughout this inquiry to calculate the wavelength and refractive index values. Computational methods may be used to analyze the proposed structure, which might aid in creating biosensors for detecting a wide variety of biomolecules and biomarkers, such as saliva-cortisol, urine, glucose, cancerous and cancerous, and hemoglobin.

A color-change fluorescence sensor for oleanolic acid based on chiral camphanic decorated bis-cyanostilbene.

Although various fluorescent sensors for biomolecules had been extensively reported, the effective fluorescent sensor was seldom reported for detecting oleanolic acid up to now. This work reports the first color-change fluorescence sensor for oleanolic acid based on a bridging bis-cyanostilbene derivative with chiral camphanic groups (C-BCS). C-BCS possessed the chartreuse fluorescence in aqueous media, which transferred to strong blue fluorescence in the presence of oleanolic acid. This sensing ability of C-BCS for oleanolic acid exhibited the high selectivity among all kinds of biomolecules and ions. The good linearity between the fluorescence intensity and concentration of oleanolic acid was acquired in the range of 0.2 × 10-6 to 8.0 × 10-6M with the detecting limitation of 0.0582μM. The 1:1 binding process was clarified as oleanolic acid located in the opening cavity composed of two bridging cyanostilbene units and two chiral camphanic groups based on multiple hydrogen bonds and hydrophobic interaction. The detecting ability of C-BCS was applied on sensing oleanolic acid in thin-layer chromatography analysis, imprinting experiment, tap water, and tea samples, suggesting the effective on-site sensing abilities of C-BCS for oleanolic acid in real samples and daily life.

Engineered Two-Dimensional Nanostructures as SERS Substrates for Biomolecule Sensing: A Review

Two-dimensional nanostructures (2DNS) attract tremendous interest and have emerged as potential materials for a variety of applications, including biomolecule sensing, due to their high surface-to-volume ratio, tuneable optical and electronic properties. Advancements in the engineering of 2DNS and associated technologies have opened up new opportunities. Surface-enhanced Raman scattering (SERS) is a rapid, highly sensitive, non-destructive analytical technique with exceptional signal amplification potential. Several structurally and chemically engineered 2DNS with added advantages (e.g., π-π* interaction), over plasmonic SERS substrates, have been developed specifically towards biomolecule sensing in a complex matrix, such as biological fluids. This review focuses on the recent developments of 2DNS-SERS substrates for biomolecule sensor applications. The recent advancements in engineered 2DNS, particularly for SERS substrates, have been systematically surveyed. In SERS substrates, 2DNS are used as either a standalone signal enhancer or as support for the dispersion of plasmonic nanostructures. The current challenges and future opportunities in this synergetic combination have also been discussed. Given the prospects in the design and preparation of newer 2DNS, this review can give a critical view on the current status, challenges and opportunities to extrapolate their applications in biomolecule detection.

Biopolymer supported electroanalytical methods for the determination of biomolecules and food additives - a comprehensive perspective.

This review aims at highlighting the significant role biopolymers play in a multitude of fields such as medical diagnostics, the cosmetics industry, food toxicity, and environmental sensing applications. The development of biomaterials, their properties, evaluation, and applications have been subjects of interest for researchers in recent years. Biomaterials and nanomaterials increase the sensing platforms' adaptability and may enable the development of sensors by taking advantage of their new and synergistic features. This review includes more than 50 research works since 2010, describing the diverse roles played by various biopolymers in the sensing field. It has been noticed that there is only a limited number of publications reported on biopolymer-supported electrochemical sensors. Hence, we offer a thorough analysis of biopolymer uses in healthcare and food detection, including those that are carbon-based, inorganic, and organic. The latest advancements in the field of biopolymer-supported electrochemical sensors for biomolecules and food additives are discussed in this review and hold tremendous potential for the application of biopolymers in the early screening of diseases and point-of-care testing.

Differential fluorescent response to amino acids based on metal-organic framework Zn-PBC.

A novel metal-organic framework (MOF) Zn-PBC (H2PBC = pyridine-3,5-bis(phenyl-4-carboxylic acid)) was designed and synthesized via a solvothermal reaction with the H2PBC ligand, and produced a strong fluorescence. The material exhibited good stability and an ideal luminescent property in water. In addition, it was found that Zn-PBC displayed a different fluorescent response to different types of amino acids, and the mechanism was investigated. This research might give insight to the interaction between MOFs and amino acids, which would provide a strategy to fabricate MOF-based sensors for biomolecules in future.

Pristine and metal decorated biphenylene monolayer for enhanced adsorption of nitrobenzene: A DFT approach

This work reports a first-principles density functional theory (DFT) investigation of nitrobenzene (NB) sensing in pristine and metal-decorated biphenylene (p-BP and m-BP, m = Sc, Cu, Li, and Pd) 2D monolayer. Though the proposed p-BP monolayer displayed excellent adsorption of NB molecule compared to other reported 2D materials, it gets physisorbed on the p-BP surface with −0.621 eV adsorption energy. The metal decoration drastically reformed the NB adsorption capacity of BP and induced remarkable changes to the electronic properties. The ab-initio molecular dynamics simulations were employed to analyze the room temperature structural integrity of the m-BP-based NB sensor. Among all the systems considered, the Pd decorated BP monolayer came out as the potential NB sensor with a reasonable adsorption energy of −1.42 eV, charge transfer of 0.38 e, the recovery time of 0.92 s at 598 K, and structural solidity at ambient temperature. The higher diffusion barrier of 0.99 eV confirmed that the Pd dopant does not show the tendency to form clusters. The study demonstrates that the Pd decorated BP is highly apposite for NB sensing and is beneficial for practical application. Our study opens a new avenue for designing and developing efficient biomolecule sensors.

Upconversion luminescent sensor for endogenous H2O2 detection in cells based on the inner filter effect of coated silver layer

We design and construct an upconversion luminescence sensor for hydrogen peroxide detection based on lanthanide-doped nanoparticles (LDN-OA). After modification with an electron-donating ligand, the silver was coated on the surface of LDN-OA in-situ by photo-induced free-electron reduction under the excitation of ultraviolet light. Then, the core-shell structure of upconversion nanoparticles growing with the silver metal surface is formed and modified with polyethylene-glycol, leading to the final hydrogen peroxide biosensor (denoted as LDN@Ag-PEG). The sensor is constructed based on the luminescence inner filter effect, using the LDN-OA as an energy donor and the coated silver layer as an energy acceptor. The confocal images were analyzed in vitro as well, presenting that the LDN@Ag-PEG sensor could achieve the sensing of endogenous hydrogen peroxide under 980 nm excitation. Thus the upconversion luminescence sensor provides a powerful idea for the development of intracellular biomolecule sensors upon near-infrared light irradiation as well.

Electrochemical and sensing properties of 2D-MoS2 nanosheets produced via liquid cascade centrifugation

In this paper, layered molybdenum disulfide (2D-MoS2) nanosheets of different size and number of layers were prepared via liquid cascade centrifugation (LCC) and their microstructural, morphological and electrochemical characteristics for the detection of dopamine (DA) and riboflavin (RF) were investigated. The microstructural and morphological characteristics of 2D-MoS2 nanosheets obtained at different centrifugation rates were evaluated by UV-Vis, Raman spectroscopy, and SEM analysis. The 2D-MoS2 nanosheets obtained showed a monotonic decrease of average lateral sheet size <L> and number of layers <N> with the increase of the centrifugation speed. Screen printed carbon electrodes (SPCE) were modified by drop casting on their surfaces 2D-MoS2 nanosheets from aqueous dispersions. The electrochemical properties of the modified 2D-MoS2/SPCE were assessed by electrical impedance spectroscopy and cyclic voltammetry in [Fe (CN)6]3−/4− redox probe. DA and RF were tested to investigate the role of <N> and <L> of MoS2 nanosheets in the electrochemical sensing of these two biomolecules. Results have shown no significant variations in the electrochemical parameters for DA sensing using the different modified electrodes. In contrast, the electro-oxidation of RF was found to be largely promoted on the 2D-MoS2-based electrode with smaller lateral size and minor number of layers, demonstrating the feasibility of tuning the electrochemical properties of 2D-MoS2 nanosheets by modifying their geometric features. The study proposes LCC as an alternative promising technique for preparing nanomaterials with enhanced performances for developing electrochemical sensors for biomolecules.

Recent Advances in Carbon Nanomaterials Based SPR Sensor for Biomolecules and Gas Detection—A Review

Nanotechnology has advanced at a rapid growth over recent years. Based on carbon nanomaterials (CNMs), surface plasmon resonance (SPR) sensors have been developed and utilized to find small amounts of low-molecular-weight compounds, including disease biomarkers, medicines, hormones, pesticides, and explosive compounds. These are necessary for disease identification in the early stages, environmental monitoring, food quality management, and explosive materials among other things. Carbon nanomaterials have been used as a supplementary layer over the plasmonic layer in SPR-based sensors. It provides a large surface area, sensitivity enhancing material, and adaptability for immobilizing numerous different biomolecules, DNA, antibodies, enzymes, and antigens as well as the detection of different gases, such as NO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , NH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> , and CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> . Recent advances in CNMs have been applied to FET nano biosensors in their designs for point-of-care patient monitoring and rapid viral diagnostics. This article presents the utilisation of CNMs in SPR-based sensors. Several sensing processes and dependent sensing parameters are discussed to make better understanding of analyte adsorption on the surface of CNMs. In addition, some current issues of CNMs-based gas sensors and biosensors are discussed here, that can lead to future study in this field.