The novel voltammetric method for determination of hesperetin based on a sensitive electrochemical sensor

Pioneering terahertz blood analysis: Hollow-core PCF with optimized sensitivity and low loss

Blood detection is crucial for the human body. Its detection is very crucial and sensitive. In this paper, a hollow core photonic crystal fiber (PCF) biosensor operating in the terahertz frequency range is proposed. The building blocks of this proposed biosensor's hexagonal cladding structure are the same square-shaped air gaps in the cladding and core. Hemoglobin, white blood cells (WBC), red blood cells (RBC), plasma and water are among the analytes that fill the core. The sensing aspects of the design will be examined using the finite element method. The COMSOL v6.1a software simulation findings show that the sensitivity for water is 93.08 percent, for plasma it is 94.55%, for hemoglobin it is 96.21%, for WBC it is 95.16%, and for RBC it is 97.05 percent. The suggested design's detection has the lowest confinement loss at frequencies between f =  1 and 2.8 THz. In addition to these, the design exhibits, under ideal design circumstances, very low and flattened dispersion, huge beam divergence, improved effective area, substantial birefringence, and negligible effective material loss. This proposed PCF biosensor is a viable option for employment in various practical applications due to its simple shape and great detecting capacity. PCF offer significant benefits for blood component analysis due to their unique structure and light-guiding properties. By enabling precise control over light-matter interaction, PCFs can be highly sensitive to the presence and characteristics of different blood components, such as red and white blood cells, platelets, hemoglobin, and glucose. This has major implications in medical diagnostics, offering advantages in speed, sensitivity, and minimally invasive testing.

Hexagonal Hollow Core PCF-Based Blood Components Sensing: Design and Simulation

Blood components play a crucial role in maintaining human health and accurately detecting them is essential for medical diagnostics. A cutting-edge sensor utilizing PCF revealed to precisely identify a wide range of blood components with WBCs (white blood cells), RBCs (red blood cells), HB (hemoglobin), platelets, and plasma. A numerical analysis was performed using COMSOL Multiphysics software to assess the capabilities of the sensor. The sensor design features a hexagonal hollow core-based PCF with a circled air hole operating wavelength from 1.0 μm to 3.0 μm. This innovative PCF sensor exhibits outstanding sensitivity, achieving relative sensitivity values of approximately 97.45% for WBCs, 99.13% for HB, 99.61% for RBCs, 93.44% for plasma, and an impressive 99.42% for platelets, all at a wavelength of 1 μm in its optimized design and this design ensures reliable and highly accurate measurements for various blood components. The corresponding effective areas are 3.32 × 10-11 m2 for WBCs, 2.91 × 10-11 m2 for HB, 2.72 × 10-11 m2 for RBCs, 3.74 × 10-11 m2 for plasma, and 2.79 × 10-11 m2 for platelets, respectively. Furthermore, The sensor demonstrates exceptional performance with remarkably low confinement loss values of 3.032 × 10-9 dB/m for WBCs, 2.947 × 10-9 dB/m for HB, 3.147 × 10-9 dB/m for RBCs, 3.112 × 10-9 dB/m for plasma, and 3.205 × 10-9 dB/m for platelets, respectively. Additionally, the effective material loss is 5.43 × 10-3 cm-1 for WBCs, 2.19 × 10-3 cm-1 for HB, 1.27 × 10-3 cm-1 for RBCs, 1.32 × 10-3 cm-1 for plasma, and 1.58 × 10-3 cm-1 for platelets. Therefore, this biosensor's outstanding sensing capabilities and innovative design make it ideal for industrial and medical applications, ensuring reliability and ease of use. The PCF-based sensor has great potential to transform optical communication applications. Its prosperity model and high sensitivity build it a valued device with the promise of addressing critical challenges in the place of biology, medicine, and communication systems. The sensor features Teflon (tetrafluoroethylene) as its background material, with air holes optimized in a five-ring structure for maximum efficiency and it is the ideal fiber material, offering excellent relative sensitivity and low confinement loss (CL). More than that, 3D printing is the ideal method for fabricating hexagonal hollow-core photonic crystal fiber (PCF) structures, allowing for the effective production of the advanced biosensor design.

Preparation of hapten and monoclonal antibody of hesperetin and establishment of enzyme-linked immunosorbent assay

Hesperetin is the aglycone of hesperidin and is widely found in the Rutaceae plants and herbal medicines. It exhibits antioxidant, detoxifying, anti-inflammatory, and antimicrobial properties, similar to hesperidin. It has also shown potential in the regulation of certain diseases. In order to detect hesperetin in complex matrix samples such as citrus and herbal, we developed an anti-hesperetin monoclonal antibody and established an indirect competitive enzyme-linked immunosorbent assay (icELISA). The half maximal inhibitory concentration (IC50) was determined to be 2.03 ng/mL, the detection range was 0.39-12.73 ng/mL. In practical sample testing, the concentration of hesperidin measured by icELISA is consistent with the result of UPLC-MS/MS, and the correlation coefficient (R2) is 0.97. These results showed that the established method has good accuracy, reproducibility and broad application prospects, and can be used for the detection of hesperetin in complex matrix samples (such as citrus and herbal samples).

Exploring the Protective Effect and Mechanism of Buddlejae Flos on Sodium Selenite-Induced Cataract in Rats by Network Pharmacology, Molecular Docking, and Experimental Validation

Objective

Buddlejae Flos has a long history of utilization by humans to treat ophthalmic diseases. Although in vitro study revealed that it can be used for treating cataract, the bioactive components and the mechanism of efficacy remained unclear. This study aims to discover the bioactive components and mode of efficacy of Buddlejae Flos in cataract treatment.

Methods

Several databases were screened for bioactive components and corresponding targets, as well as cataract-related targets. Using the String database, common targets were determined and utilized to construct protein-protein interactions (PPI). The drug-component-target-disease network map was drawn using Cytoscape software. R language was utilized to execute Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) pathway enrichment analysis. Molecular docking was done through Schrödinger Maestro software utilization. Luteolin's (LUT) effect on cataract induced by sodium selenite in rat pups was evaluated.

Results

Six bioactive components with 38 common targets were identified as being associated with cataract. TP53, AKT1, EGFR, CASP3, TNF, ESR1, INS, IL6, HIF1A, and VEGFA were identified as core targets in PPI analysis, and the binding energy of LUT with AKT was the lowest. LUT has been demonstrated to significantly lower MDA levels, raise glutathione (GSH) levels, and boost the activity of antioxidant enzymes like GST, SOD, GPx, and CAT. After LUT treatment, TNF-a, IL-2, and IL-6 levels were significantly lowered. Bcl-2 mRNA expression levels and p-PI3K and p-AKT protein expression were significantly elevated. In contrast, caspase-3 and Bax mRNA expression levels were significantly decreased.

Conclusion

This study demonstrates that LUT is a possible bioactive component that may be utilized for cataract treatment. Its mode of action includes oxidative stress suppression, reducing inflammation, and inhibiting apoptosis via regulating the PI3K/AKT single pathway.

Green synthesis of kudzu vine biochar decorated graphene-like MoSe2 with the oxidase-like activity as intelligent nanozyme sensing platform for hesperetin

It is an urgent need to exploit a potentially green, cost efficient and eco-friendly strategy for the utilization of waste kudzu vine. We developed a one-step green preparation of kudzu vine biochar (BC) decorated graphene-like molybdenum selenide (MoSe₂) with the oxidase-like activity as intelligent nanozyme sensing platform for voltametric detection of hesperetin (HP) in orange peel using the in-situ hydrothermal synthesis method. The structure and properties of MoSe₂-BC was characterized, and found that BC significantly improved electrochemical cycle stability, electronic conductivity, electrochemical active area, and electrocatalytic activity of MoSe₂. The oxidase-like activity of MoSe₂-BC was confirmed by the oxidization of the colorless substrate 3,3',5,5'-tetramethylbenzidine (TMB) to form blue products and the change of absorbance intensity of UV-vis absorption spectra. The MoSe₂-BC exhibited excellent electrochemical sensing performance for the detection of HP in wide linear ranges from 10 nM to 9.5 μM with a low limit of detection of 2 nM using differential pulse voltammetric method. An emerging machine learning technique is used to realize the intelligent sensing of HP, and the performance evaluation of regression analysis was selected to evaluate this technique. This work will provide a guidance for the preparation and application of biochar decorated graphene-like nanomaterials with the oxidase-like activity and the development of intelligent nanozyme sensing platform.

Formation and Electrochemical Evaluation of Polyaniline and Polypyrrole Nanocomposites Based on Glucose Oxidase and Gold Nanostructures

Nanocomposites based on two conducting polymers, polyaniline (PANI) and polypyrrole (Ppy), with embedded glucose oxidase (GOx) and 6 nm size gold nanoparticles (AuNPs_(6nm)) or gold-nanoclusters formed from chloroaurate ions (AuCl₄⁻), were synthesized by enzyme-assisted polymerization. Charge (electron) transfer in systems based on PANI/AuNPs_(6nm)-GOx, PANI/AuNPs_(AuCl4⁻₎-GOx, Ppy/AuNPs_(6nm)-GOx and Ppy/AuNPs_(AuCl4⁻₎-GOx nanocomposites was investigated. Cyclic voltammetry (CV)-based investigations showed that the reported polymer nanocomposites are able to facilitate electron transfer from enzyme to the graphite rod (GR) electrode. Significantly higher anodic current and well-defined red-ox peaks were observed at a scan rate of 0.10 V s⁻¹. Logarithmic function of anodic current (log I_pa), which was determined by CV-based experiments performed with glucose, was proportional to the logarithmic function of a scan rate (log v) in the range of 0.699–2.48 mV s⁻¹, and it indicates that diffusion-controlled electrochemical processes were limiting the kinetics of the analytical signal. The most efficient nanocomposite structure for the design of the reported glucose biosensor was based on two-day formed Ppy/AuNPs_(AuCl4⁻₎-GOx nanocomposites. GR/Ppy/AuNPs_(AuCl4⁻₎-GOx was characterized by the linear dependence of the analytical signal on glucose concentration in the range from 0.1 to 0.70 mmol L⁻¹, the sensitivity of 4.31 mA mM cm⁻², the limit of detection of 0.10 mmol L⁻¹ and the half-life period of 19 days.

Preparation and application of a carbon paste electrode modified with multi-walled carbon nanotubes and boron-embedded molecularly imprinted composite membranes

An innovative electrochemical sensor was fabricated for the sensitive and selective determination of tinidazole (TNZ), based on a carbon paste electrode (CPE) modified with multi-walled carbon nanotubes (MWCNTs) and boron-embedded molecularly imprinted composite membranes (B-MICMs). Density functional theory (DFT) calculations were carried out to investigate the utility of template-monomer interactions to screen appropriate monomers for the rational design of B-MICMs. The distinct synergic effect of MWCNTs and B-MICMs was evidenced by the positive shift of the reduction peak potential of TNZ at B-MICMs/MWCNTs modified CPE (B-MICMs/MWCNTs/CPE) by about 200 mV, and the 12-fold amplification of the peak current, compared with a bare carbon paste electrode (CPE). Moreover, the coordinate interactions between trisubstituted boron atoms embedded in B-MICMs matrix and nitrogen atoms of TNZ endow the sensor with advanced affinity and specific directionality. Thereafter, a highly sensitive electrochemical analytical method for TNZ was established by different pulse voltammetry (DPV) at B-MICMs/MWCNTs/CPE with a lower detection limit (1.25 × 10^-12 mol L^-1) (S/N = 3). The practical application of the sensor was demonstrated by determining TNZ in pharmaceutical and biological samples with good precision (RSD 1.36% to 3.85%) and acceptable recoveries (82.40%-104.0%).

Highly sensitive detection of hesperidin using AuNPs/rGO modified glassy carbon electrode

The highly sensitive and selective electrochemical sensor of hesperidin based on gold nanoparticles (AuNPs) and reduced graphene oxide (rGO) modified glassy carbon electrode (GCE) is reported.