Fabrication of graphene nanoribbon-based enzyme-free electrochemical sensor for the sensitive and selective analysis of rutin in tablets

Fabrication of hybrid nanocomposites for electrochemical evaluation of food-based preservative and bioactive targets of hydrogen peroxide and rutin in real fruit and drug samples

Development of a reliable tool to detect hydrogen peroxide (H2O2) and rutin in food-derived products and bioactive flavonoids is essential for food safety. Nevertheless, food/drug-based real samples are complex matrices that affect the sensor's specificity and sensitivity. For this purpose, we developed a simple electrochemical detection platform using covalent organic framework‑silver nanoparticles (COF-AgNPs). Based on spectral and electrochemical tests, COF-AgNPs displayed enhanced electroactive sites and facile electron transfer. For H2O2 and rutin, the designed sensor surface exhibited outstanding concentration linearity of 0.5 nM-1000 μM and 1 nM-900 μM, respectively, along with superior detection limits of 0.126 nM and 0.133 nM. Additionally, it demonstrated acceptable reproducibility and interference capability. In practical analysis, H2O2 and rutin were detected in milk, fruits, and drug samples with high recovery rates of 94.60-99.31 % (n = 3). Consequently, the designed sensor is ideal for screening targets for H2O2 and rutin in food sources and for food research.

Monitoring of Specific Phytoestrogens by Dedicated Electrochemical Sensors: A Review

Phytoestrogens are non-steroidal estrogens produced from plants that can bind with the human body's estrogenic receptor site and be used as a substitute for maintaining hormonal balance. They are mainly classified as flavonoids, phenolic acids, lignans, stilbenes, and coumestans; some are resocyclic acids of lactones, which are mycotoxins and not natural phytoestrogen. Phytoestrogens have many beneficial medicinal properties, making them an important part of the daily diet. Electrochemical sensors are widely used analytical tools for analysing various pharmaceuticals, chemicals, pollutants and food items. Electrochemical sensors provide an extensive platform for highly sensitive and rapid analysis. Several reviews have been published on the importance of the biological and medicinal properties of phytoestrogens. However, this review provides an overview of recent work performed through electrochemical measurements with electrochemical sensors and biosensors for all the classes of phytoestrogens done so far since 2019.

CuMoO4/Ti3C2Tx nanocomposite layers perform as an ultrasensitive electrochemical sensor for the detection of antioxidant rutin

The focus of this paper is laid on synthesizing layered compounds of CuMoO4 and Ti3C2Tx using a simple wet chemical etching method and sonochemical method to enable rapid detection of rutin using an electrochemical sensor. Following structural examinations using XRD, surface morphology analysis using SEM, and chemical composition state analysis using XPS, the obtained CuMoO4/Ti3C2Tx nanocomposite electrocatalyst was confirmed and characterized. By employing cyclic voltammetry and differential pulse voltammetry, the electrochemical properties of rutin on a CuMoO4/Ti3C2Tx modified electrode were examined, including its stability and response to variations in pH, loading, sweep rate, and interference. The CuMoO4/Ti3C2Tx modified electrode demonstrates rapid rutin sensing under optimal conditions and offers a linear range of 1 µΜ to 15 µΜ, thereby improving the minimal detection limit (LOD) to 42.9 nM. According to electrochemical analysis, the CuMoO4/Ti3C2Tx electrode also demonstrated cyclic stability and long-lasting anti-interference capabilities. The CuMoO4/Ti3C2Tx nanocomposite demonstrated acceptable recoveries when used to sense RT in apple and grape samples. In comparison to other interfering sample analytes encountered in the current study, the developed sensor demonstrated high selectivity and anti-interference performance. As a result, our research to design of high-performance electrochemical sensors in the biomedical and therapeutic fields.

A Wireless, CRISPR-Polymer Dot Electrochemical Sensor for the Diagnosis of Bacterial Pneumonia and Multi-Drug Resistance

Rapid and accurate diagnosis is crucial for managing the global health threat posed by multidrug-resistant bacterial infections; however, current methods have limitations in either being time-consuming, labor-intensive, or requiring instruments with high costs. Addressing these challenges, we introduce a wireless electrochemical sensor integrating the CRISPR/Cas system with electroconductive polymer dot (PD) nanoparticles to rapidly detect bacterial pathogens from human sputum. To enhance the electroconductive properties, we synthesized copper-ion-immobilized PD (PD-Cu), followed by conjugation of the deactivated Cas9 protein (dCas9) onto PD-Cu-coated Si electrodes to generate the dCas9-PD-Cu sensor. The dCas9-PD-Cu sensor integrated with isothermal amplification can specifically detect target nucleic acids of multidrug-resistant bacteria, such as the antibiotic resistance genes kpc-2 and mecA. The dCas9-PD-Cu sensor exhibits high sensitivity, allowing for the detection of ∼54 femtograms of target nucleic acids, based on measuring the changes in resistivity of the Si electrodes through target capture by dCas9. Furthermore, a wireless sensing platform of the dCas9-PD-Cu sensor was established using a Bluetooth module and a microcontroller unit for detection using a smartphone. We demonstrate the feasibility of the platform in diagnosing multidrug-resistant bacterial pneumonia in patients' sputum samples, achieving 92% accuracy. The current study presents a versatile biosensor platform that can overcome the limitations of conventional diagnostics in the clinic.

Fast Determination of Rutin on a Biosensor Made Using a Layered Double Hydroxide Nanocomposite Modified Electrode

In this study, a nanocomposite of LDH/graphene/polyaniline/gold (LDH/rGO/PANI/Au) was synthesized and characterized. The results of characterization showed that the composite material preserved the layered structure of LDH. The composite was dropped onto the glassy carbon electrode and laccase was then immobilized. Electrochemical tests showed that the composite could accelerate the electron transfer between the enzyme and the electrode. The composite/laccase showed an obvious response to rutin and the optimal detection conditions were discussed. The oxidative peak current of the biosensor constructed using the modified electrode was negatively correlated with rutin in the range of 0.05-4 μg/mL. The detection limit was 0.0017 μg/mL at a signal-to-noise ratio of 3. This biosensor of rutin also possessed high sensitivity, excellent anti-interference ability, and stability. The contents of rutin in tablets, first determined using HPLC, were also detected using the sensor constructed in this research as an application, and the results were acceptable. This research here provides a facile way for the fast detection of rutin in real samples.

Portable Wireless Intelligent Electrochemical Sensor for the Ultrasensitive Detection of Rutin Using Functionalized Black Phosphorene Nanocomposite

To build a portable and sensitive method for monitoring the concentration of the flavonoid rutin, a new electrochemical sensing procedure was established. By using nitrogen-doped carbonized polymer dots (N-CPDs) anchoring few-layer black phosphorene (N-CPDs@FLBP) 0D-2D heterostructure and gold nanoparticles (AuNPs) as the modifiers, a carbon ionic liquid electrode and a screen-printed electrode (SPE) were used as the substrate electrodes to construct a conventional electrochemical sensor and a portable wireless intelligent electrochemical sensor, respectively. The electrochemical behavior of rutin on the fabricated electrochemical sensors was explored in detail, with the analytical performances investigated. Due to the electroactive groups of rutin, and the specific π-π stacking and cation-π interaction between the nanocomposite with rutin, the electrochemical responses of rutin were greatly enhanced on the AuNPs/N-CPDs@FLBP-modified electrodes. Under the optimal conditions, ultra-sensitive detection of rutin could be realized on AuNPs/N-CPDs@FLBP/SPE with the detection range of 1.0 nmol L^-1 to 220.0 μmol L^-1 and the detection limit of 0.33 nmol L^-1 (S/N = 3). Finally, two kinds of sensors were applied to test the real samples with satisfactory results.

MWCNTs-CTAB and HFs-Lac Nanocomposite-Modified Glassy Carbon Electrode for Rutin Determination

Rutin is a flavonoid glycoside compound, which is mainly transported via the blood circulation system in the human body. The monitoring of the blood concentration of rutin is of great significance in many fields such as pharmacology and pharmacokinetics. In this work, a biosensor based on multi-walled carbon nanotubes (MWCNTs), cetyltrimethylammonium bromide (CTAB), hydroxyl fullerenes (HFs), and laccase (Lac) nanocomposite-modified glassy carbon electrodes was constructed. The modified materials were characterized with a transmission electron microscope (TEM), cyclic voltammograms (CV), and electrochemical impedance spectroscopy (EIS). CTAB is used to disperse MWCNTs and improve hydrophilicity and biocompatibility of MWCNTs, while the use of Lac can enhance the oxidation of catechol structure in rutin, thus significantly improving the sensitivity and selectivity of the modified electrode. Linear sweep voltammetry (LSV) studies showed that the determination linear ranges of rutin were 0.1 µmol L⁻¹ to 2 µmol L⁻¹ and 2 µmol L⁻¹ to 11 µmol L⁻¹, with the determination limits of 30 nmol L⁻¹ and 95.5 nmol L⁻¹, respectively. The proposed biosensor can be used to detect rutin tablets and serum samples with high recovery, which indicates a good accuracy of this method, and the results are consistent with those measured by the traditional ultra-high performance liquid chromatography (UHPLC) method. Hence, this biosensor has potential practical application value in rutin drug quality testing and clinical blood drug concentration monitoring.