Novel ruthenium-doped vanadium carbide/polymeric nanohybrid sensor for acetaminophen drug detection in human blood.

The use of advanced electroactive catalysts enhances the performance of electrochemical biosensors in real-time biomonitoring and has received much attention owing to its excellent physicochemical and electrochemical possessions. In this work, a novel biosensor was developed based on the electrocatalytic activity of functionalized vanadium carbide (VC) material, including VC@ruthenium (Ru), VC@Ru-polyaniline nanoparticles (VC@Ru-PANI-NPs) as non-enzymatic nanocarriers for the fabrication of modified screen-printed electrode (SPE) to detect acetaminophen in human blood. As-prepared materials were characterized using SEM, TEM, XRD, and XPS techniques. Biosensing was carried out using cyclic voltammetry and differential pulse voltammetry techniques and has revealed imperative electrocatalytic activity. A quasi-reversible redox method of the over-potential of acetaminophen increased considerably compared with that at the modified electrode and the bare SPE. The excellent electrocatalytic behaviour of VC@Ru-PANI-NPs/SPE is attributed to its distinctive chemical and physical properties, including rapid electron transfer, striking á´«-á´« interface, and strong adsorptive capability. This electrochemical biosensor exhibits a detection limit of 0.024 µM, in a linear range of 0.1-382.72 µM with a reproducibility of 2.45 % relative standard deviation, and a good recovery from 96.69 % to 105.59 %, the acquired results ensure a better performance compared with previous reports. The enriched electrocatalytic activity of this developed biosensor is mainly credited to its high surface area, better electrical conductivity, synergistic effect, and abundant electroactive sites. The real-world utility of the VC@Ru-PANI-NPs/SPE-based sensor was ensured via the investigation of biomonitoring of acetaminophen in human blood samples with satisfactory recoveries.

Eco-friendly fabrication of nonenzymatic electrochemical sensor based on cobalt/polymelamine/nitrogen-doped graphitic-porous carbon nanohybrid material for glucose monitoring in human blood.

The design and development of eco-friendly fabrication of cost-effective electrochemical nonenzymatic biosensors with enhanced sensitivity and selectivity are one of the emerging area in nanomaterial and analytical chemistry. In this aspect, we developed a facile fabrication of tertiary nanocomposite material based on cobalt and polymelamine/nitrogen-doped graphitic porous carbon nanohybrid composite (Co-PM-NDGPC/SPE) for the application as a nonenzymatic electrochemical sensor to quantify glucose in human blood samples. Co-PM-NDGPC/SPE nanocomposite electrode fabrication was achieved using a single-step electrodeposition method under cyclic voltammetry (CV) technique under 1 M NH4Cl solution at 20 constitutive CV cycles (sweep rate 20 mV/s). Notably, the fabricated nonenzymatic electroactive nanocomposite material exhibited excellent electrocatalytic sensing towards the quantification of glucose in 0.1 M NaOH over a wide concentration range from 0.03 to 1.071 mM with a sensitive limit of detection 7.8 µM. Moreover, the Co-PM-NDGPC nanocomposite electrode with low charge transfer resistance (Rct∼81 Ω) and high ionic diffusion indicates excellent stability, reproducibility, and high sensitivity. The fabricated nanocomposite materials exhibit a commendable sensing response toward glucose molecules present in the blood serum samples recommends its usage in real-time applications.

Novel biomass-derived porous-graphitic carbon coated iron oxide nanocomposite as an efficient electrocatalyst for the sensitive detection of rutin (vitamin P) in food and environmental samples.

Design and development of inexpensive, portable, and eco-friendly electrochemical non-enzymatic sensors with high selectivity and sensitivity is pivotal in analytical chemistry. In this regard, we have developed a highly porous graphitic-activated carbon (GAC, derived from tamarind fruit shell biomass) coated iron oxide (Fe2O3) nanocomposite (Fe2O3/GAC) for the efficient detection of rutin (vitamin p). Fe2O3/GAC nanocomposite was prepared using a facile green synthesis method and thoroughly characterized using SEM, XRD, and XPS techniques. As-prepared Fe2O3/GAC nanocomposite was deposited over a screen printed electrode (SPE) to fabricate Fe2O3/GAC/SPE and utilized as a non-enzymatic sensor for the electrochemical determination of rutin in food and environmental samples. The modified electrode was characterized using cyclic voltammetry and electrochemical impedance spectroscopy techniques, which witnessed the excellent conductivity of the developed sensor. The fabricated Fe2O3/GAC/SPE nanocomposite exhibited a set of redox peaks in the presence of rutin, corresponding to the electrochemical redox feature of rutin (rutin to 3',4'-diquinone). Further, the modified electrode displayed excellent electrocatalytic characteristics towards the oxidation of rutin, based on which a differential pulse voltammetry-based sensor was developed for rutin determination. The developed non-enzymatic sensor has shown prominent performance towards rutin detection in a wide linear range from 0.1 to 130 µM with an excellent detection limit of 0.027 µM. The enhanced electrocatalytic response could be ascribed to the synergistic effect of Fe2O3 and GAC on the developed probe. Moreover, the developed sensor was successfully utilized for real-time detection of rutin in various samples.

Novel delipidated chicken feather waste-derived carbon-based molybdenum oxide nanocomposite as efficient electrocatalyst for rapid detection of hydroquinone and catechol in environmental waters.

Chicken poultry industry produces a vast amount of feather waste and is often disposed into landfills, creating environmental pollution. Therefore, we explored the valorization of chicken feather waste into lipids and keratinous sludge biomass. This study demonstrates the successful utilization of keratinous sludge biomass as a unique precursor for the facile preparation of novel keratinous sludge biomass-derived carbon-based molybdenum oxide (KSC@MoO3) nanocomposite material using two-step (hydrothermal and co-pyrolysis) processes. The surface morphology and electrochemical properties of as-prepared nanocomposite material were analyzed using HR-SEM, XRD, XPS, and cyclic voltammetric techniques. KSC@MoO3 nanocomposite exhibited prominent electrocatalytic behavior to simultaneously determine hydroquinone (HQ) and catechol (CC) in environmental waters. The as-prepared electrochemical sensor showed excellent performance towards the detection of HQ and CC with broad concentration ranges between 0.5-176.5 µM (HQ and CC), and the detection limits achieved were 0.063 µM (HQ) and 0.059 µM (CC). Furthermore, the developed modified electrode has exhibited excellent stability and reproducibility and was also applied to analyze HQ and CC in environmental water samples. Results revealed that chicken feather waste valorization could result in sustainable biomass conversion into a high-value nanomaterial to develop a cost-effective electrochemical environmental monitoring sensor and lipids for biofuel.

Facile strategy for immobilizing horseradish peroxidase on a novel acetate functionalized ionic liquid/MWCNT matrix for electrochemical biosensing.

Facile yet simple platforms for the immobilization of biomolecules have always been a substantial requirement for the fabrication of proficient biosensors. In this study, we report a naphthyl substituted acetate functionalized ionic liquid (NpAc-IL) for the covalent anchoring of horseradish peroxidase (HRP), using which the direct electrochemistry of HRP was successfully accomplished and a H2O2 biosensor was developed. The naphthyl substitution on the NpAc-IL was utilized for the π-π stacking with the MWCNT modified GCE and the terminal -OCH3 group of NpAc-IL was used for the covalent attachment with the free -NH2 group of HRP via amide bond formation. High conducting nature of the newly designed ionic liquid (NpAc-IL), facilitated an improved communication with the deeply buried redox centre of the HRP, while the covalent bonding provided enhanced stability to the fabricated biosensor by stably holding the water soluble HRP enzyme on the electrode surface. Furthermore, incorporation of MWCNT on the sensor setup synergistically enhanced the sensitivity of the developed biosensor. Under optimized conditions, the fabricated biosensor showed an enhanced electrocatalytic reduction of H2O2 in the range of 0.01 to 2.07 mM with a limit of detection and sensitivity of 2.7 µM and 55.98 µA mM-1 cm-2 respectively. Further, the proposed biosensor was utilized for the sensing of H2O2 spiked in real samples. Moreover, the newly fabricated biosensor demonstrated excellent stability with improved sensitivity and selectivity towards H2O2 reduction. The superior analytical characteristics are attributed to the facile fabrication strategy using this newly developed acetate functionalized ionic liquid platform.