Double strand DNA-based determination of menadione using a Fe3O4 nanoparticle decorated reduced graphene oxide modified carbon paste electrode

Nanoengineered lanthanum niobate nanocaviar anchored carbon nanofibers for trace level detection of menadione in environmental samples

An innovative sensor is prepared by electrode modification through a nano-ranged electrode modifier composed of LaNbO₄ nano caviars decorated on the enmeshed carbon nanofibers to identify excess vitamins in animal feed. Menadione (Vitamins K3) is a micronutrient fundamentally required in precise quantities for animal health upkeep. Still, its exploitation has recently resulted in water reservoir contamination through waste generated from animal husbandry. Sustainable prevention of water contamination makes menadione detection highly imperative and flickered the attention of researchers. Considering these aspects, a novel menadione sensing platform is designed by interdisciplinary incorporation of nanoscience and electrochemical engineering. The structural and crystallographic features and the electrode modifier's morphological insights were keenly investigated. The hierarchal arrangement of individual constituents in nanocomposite is benefited through hybrid heterojunction and quantum confinement that synchronously activate the menadione detection with a LOD of 68.5 nM and 67.49 nM for oxidation and reduction, respectively. The as-prepared sensor has a wide linear range (0.1-173.6 μM), high sensitivity, good selectivity, and stability. The application of this sensor is extended to a water sample to monitor the consistency of the proposed sensor.

Biosensing platform on ferrite magnetic nanoparticles: Synthesis, functionalization, mechanism and applications

Ferrite magnetic nanoparticles (FMNPs) are gaining popularity to design biosensors for high-performance clinical diagnosis. The fusion of information shows that FMNPs based biosensors require well-tuned FMNPs as detection probes to produce large and specific biological signals with minimal non-specific binding. Nevertheless, there is a noticeable lacuna of information to solve the issues related to suitable synthesis route, particle size reduction, functionalization, sensitivity towards targeted intercellular biological tiny particles, and lower signal-to-noise ratio. Therefore it allows exploring unique characteristics of FMNPs to design a suitable sensing device for intracellular measurements and diseases detection. This review focuses on the extensively used synthesis routes, their advantages and limitations, crystalline structure, functionalization, along with recent applications of FMNPs in biosensors, taking into consideration their analytical figures of merit and range of linearity. This work also addresses the current progress, key factors for sensitivity, selectivity and productivity improvement along with the challenges, future trends and perspectives of FMNPs based biosensors.

Aluminosilicate Nanocomposite on Genosensor: A Prospective Voltammetry Platform for Epidermal Growth Factor Receptor Mutant Analysis in Non-small Cell Lung Cancer

Lung cancer is one of the most serious threats to human where 85% of lethal death caused by non-small cell lung cancer (NSCLC) induced by epidermal growth factor receptor (EGFR) mutation. The present research focuses in the development of efficient and effortless EGFR mutant detection strategy through high-performance and sensitive genosensor. The current amplified through 250 µm sized fingers between 100 µm aluminium electrodes indicates the voltammetry signal generated by means of the mutant DNA sequence hybridization. To enhance the DNA immobilization and hybridization, ∼25 nm sized aluminosilicate nanocomposite synthesized from the disposed joss fly ash was deposited on the gaps between aluminium electrodes. The probe, mutant (complementary), and wild (single-base pair mismatch) targets were designed precisely from the genomic sequences denote the detection of EGFR mutation. Fourier-transform Infrared Spectroscopy analysis was performed at every step of surface functionalization evidences the relevant chemical bonding of biomolecules on the genosensor as duplex DNA with peak response at 1150 cm⁻¹ to 1650 cm⁻¹. Genosensor depicts a sensitive EGFR mutation as it is able to detect apparently at 100 aM mutant against 1 µM DNA probe. The insignificant voltammetry signal generated with wild type strand emphasizes the specificity of genosensor in the detection of single base pair mismatch. The inefficiency of genosensor in detecting EGFR mutation in the absence of aluminosilicate nanocomposite implies the insensitivity of genosensing DNA hybridization and accentuates the significance of aluminosilicate. Based on the slope of the calibration curve, the attained sensitivity of aluminosilicate modified genosensor was 3.02E-4 A M⁻¹. The detection limit of genosensor computed based on 3σ calculation, relative to the change of current proportional to the logarithm of mutant concentration is at 100 aM.