Stripping voltammetric behaviour of toxic drug nitrofurantoin

Turn-off fluorescence of S,N-doped carbon dots for determination of two nitro-containing drugs in dosage forms and human plasma

This study describes the development of an environmentally-friend optical nanosensor for the rapid spectrofluorimetric assessment of two nitro-compounds, namely nitrofurantoin and dantrolene in their dosage forms and plasma samples. A one-step synthetic technique successfully created very bright water-soluble carbon quantum dots doped with sulfur and nitrogen (S,N-CQDs). Carbon was derived from citric acid, while nitrogen and sulfur were obtained from thiosemicarbazide. The dimensions of the synthesized dots were measured using a high-resolution transmission electron microscope. FT-IR spectroscopy was used to determine which functional groups were located on their surfaces. The nanosensor's fluorescence emission peaked intensely at 415 nm after excitation at 345 nm with a quantum yield of about 0.52. The inherent fluorescence of the nanosensors gradually decreased upon addition of the studied analytes in increasing concentrations. The fluorescence reduction of nanosensor with the concentrations of the investigated drugs demonstrated linear correlation within the ranges of 0.5-8.0 μg/mL and 1.0-10.0 μg/mL with limits of detection of 0.14 μg/mL (0.59 μM) and 0.23 μg/mL (0.73 μM) for nitrofurantoin and dantrolene, respectively. The recommended method was used to determine the concentrations of the investigated drugs in their commercial capsules, with recoveries ranging from 97.90 % to 101.57 % and low percent RSD values less than 2 %. Moreover, the method was adapted for the in-vitro analysis of the two analytes in spiked human plasma samples with % recoveries from 95.20 % to 102.20 %. The mechanism of interaction between each analyte and the dots was also investigated. The selectivity of the approach for measuring analytes concentration in the presence of excipients, co-formulated medications, or co-administered pharmaceuticals was further evaluated through an interference study. The suggested method's validity was evaluated in accordance with ICH criteria.

Hybrid structures of cobalt-molybdenum bimetallic oxide embedded in flower-like molybdenum disulfide for sensitive detection of the antibiotic drug nitrofurantoin

Excessive residues of nitrofurantoin (NFT) can cause serious contamination of water bodies and food, and potential harm to ecosystems and food safety. Given that, rapid and efficient detection of NFT in real samples is of particular importance. MoS₂ is a promising electrochemical material for this application. Here, MoS₂ was modulated by Metal-organic framework through the interfacial microenvironment to enhance the catalytic activity and carbonized to form Co₂Mo₃O₈ nanosheets with high electrical activity. The resulting Co₂Mo₃O₈/MoS₂ hybrid structure can be used to prepare highly sensitive NFT electrochemical sensor. The Co₂Mo₃O₈/MoS₂@CC electrochemical sensor exhibits strong electrochemical properties due to its fast electron transfer, excellent electrical conductivity, abundant defect sites, and high redox response. Based on this, this electrochemical sensor exhibited excellent electrocatalytic activity for NFT with a wide linear detection range, low detection limit, and high sensitivity. Moreover, the electrode was successfully applied to detect NFT in milk, honey, and tap water, strongly confirming its potential in real samples. This work could furnish the evidence for interfacial microenvironmental regulation of MoS₂, and also offer a novel candidate material for NFT sensing.

Amorphous cobalt boride nanosheets anchored surface-functionalized carbon nanofiber: An bifunctional and efficient catalyst for electrochemical sensing and oxygen evolution reaction

Development of new metal boride with carbon composite is an emerging class of catalyst and it brings enormous curiosity in the material community because of their potential intriguing properties. Here, we describe a new type of amorphous cobalt boride (A-CoB) nanosheet anchored on the surface of functionalized carbon nanofiber (A-CoB/ƒ-CNF) by a simple method. The emerged A-CoB/ƒ-CNF composite was demonstrated to possess great bifunctional electrocatalytic activity for the electrochemical sensing of antibiotic drug nitrofurantoin (NFT) and oxygen evolution reaction (OER). The prepared A-CoB/ƒ-CNF composite was characterized by various analytical and spectroscopic techniques such as XRD, FE-SEM, HR-TEM, Raman, and XPS analysis. The result from the electrochemical impedance spectroscopy confirms that the A-CoB/ƒ-CNF composite shows high electrical conductivity and the number of electron transferability for the NFT sensor and OER which is due to the presence of abundant active sites/large surface area in A-CoB, and synergistic effect between the A-CoB and ƒ-CNF. As an electrochemical sensor, the A-CoB/ƒ-CNF modified electrode shows substantial sensitivity (3.13 μA μM^-1 cm^-2), wider linear response range (0.01- 527 μM), and lower detection limit (0.003 μM) as-compared to the previously reported noble and non-noble metal-based electrocatalyst for NFT sensor. As well, the A-CoB/ƒ-CNF composite demonstrates superior OER activity with low overpotential and small Tafel slope value of 0.35 V and 173 mV/dec, respectively, which shows advanced kinetics than noble metal catalysts. Based on the results, we believed that the present work gives clear evidence for the preparation of transition metal boride anchored carbon material with an outstanding catalytic activity, and hence, it can be also extended to further electrochemical applications.

Nano assembly of NiFe spheres anchored on f-MWCNT for electrocatalytic reduction and sensing of nitrofurantoin in biological samples

The current study reports a facile simple, low-cost electrochemical sensor in the detection of nitrofurantoin (NFT) by using NiFe/f-MWCNT hybrid composite as a promising electrocatalyst. NFT is an antibiotic drug that is extensively using in pharmaceuticals and also in animal food production which causes a severe threat for both human and animal environments. Extending the residues of NFT are left into rivers, soils, lakes, and groundwaters either found or discharged leading health issues. To this NiFe/f-MWCNT composite was synthesized using a hydrothermal mechanism and then ultrasonicated to form a hybrid composite for catalytic evaluation and electrochemical detection of NFT for the very first time. Furthermore, the physicochemical properties of NiFe nanospheres conjugated on f-MWCNT are scrutinized using various analytical and spectroscopical techniques. Resulting transmission electron microscopy (TEM) displays a chain like NiFe nanospheres anchored on f-MWCNT with a well-defined spherical shape, without any comprehensive agglomeration. The NiFe/f-MWCNT screen printed carbon paste electrode (SPCE) displayed an excellent electrocatalytic activity for NFT with a LOD of 0.03 µM and a sensitivity of 11.45 µA µM^-1 cm^-2. establishing a new selectivity and with the existence of co-interfering compounds. To enhance the practical abilities analysis were performed in Human serum and urine samples which resulted in satisfactory recoveries with high precision and linear accuracy illustrated in Scheme 1.

Ultrasonic assisted functionalization of MWCNT and synergistic electrocatalytic effect of nano-hydroxyapatite incorporated MWCNT-chitosan scaffolds for sensing of nitrofurantoin

In the present work, we report the fabrication of stable composite of chitosan hydrogels (CHI) on multiwalled carbon nanotubes (MWCNT) using a simple ultrasonic-assisted method. Also, rod-like hydroxyapatite nanoparticles (HA NPs) were synthesised using a hydrothermal route and were incorporated into the highly conductive MWCNT-CHI scaffolds using an ultrasonication method. The functionalization of MWCNT and preparation of HA NPs on MWCNT-CHI nanocomposite were done using the sonication over the frequency of 37 kHz with the ultrasonic power capable of 150 W (Elmasonic Easy 60H bath sonicator). The resulting hybrid HA NPs/MWCNT-CHI nanocomposites have an excellent surface area and high surface to volume ratio, which leads to the sensitive detection of nitrofurantoin than pristine MWCNT and HA NPs. The complete elemental and morphological analyses of the HA NPs/MWCNT-CHI nanocomposites were characterised by XRD, FTIR, RAMAN, FESEM, TEM, EDX, and elemental mapping techniques. Electrochemical analysis of the HA NPs/MWCNT-CHI nanocomposites was carried out by cyclic voltammetry, electrochemical impedance spectroscopy and amperometry methods. The modified glassy carbon electrode (GCE) of HA NPs/MWCNT-CHI nanocomposites exhibit the nitrofurantoin detection activity at the linear range of 0.005-982.1 µM with the detection limit of 1.3 nM. The synergistic electrocatalytic activity of HA NPs/MWCNT-CHI nanocomposites modified GCE is correlated to the sensitivity of 0.16 µAµM^-1 cm^-2 with excellent precision and accuracy towards the sensing of nitrofurantoin.

Robust and selective electrochemical detection of antibiotic residues: The case of integrated lutetium vanadate/graphene sheets architectures

Lutetium vanadate (LuVO₄) is a promising material for electrochemical application owing to its good conductivity and electrocatalytic activity. Herein, we demonstrate a facile technique for the synthesis of a LuVO₄/ graphene sheet (GRS) nanocomposite where LuVO₄ is encapsulated with an ultrathin GRS to form a hierarchical structure (LuVO₄/GRS). The resulting hierarchical LuVO4/GRS architecture was characterized by several analytical and spectroscopic techniques. The resultant electrocatalyst shows superior electrochemical sensing for nitrofurantoin (NFT) with a low detection limit (0.001 μM), wide linear range (0.008-256.0 μM) and excellent sensitivity (1.709 μA μM^-1 cm^-2). It has been demonstrated that the enhanced electrocatalytic performance of LuVO₄/GRS nanocomposite is due to their excellent electrical conductivity, suitable surface area, high redox reaction and large number of electron transport. In addition, the LuVO₄/GRS nanocomposite exhibited excellent response towards NFT detection with adequate reproducibility, good repeatability, long-term stability and excellent selectivity over its structural analogs and common interferents. Furthermore, the practical applicability of the proposed electrochemical sensor was successfully applied for determination of NFT in environmental samples with satisfactory results. The LuVO₄/GRS nanocomposite presented here can serve as a favorable candidate for developing electrochemical sensor and plays an important role in widespread fields.

Facile synthesis of ultrathin NiSnO3 nanoparticles for enhanced electrochemical detection of an antibiotic drug in water bodies and biological samples

The highly sensitive real-time detection of antibiotic drugs (nitrofurantoin; NFT) has drawn significant research attention due to the extensive use of antibiotics, which may cause serious threats to environment as well as living things.

Ultrasonic energy-assisted preparation of β-cyclodextrin-carbon nanofiber composite: Application for electrochemical sensing of nitrofurantoin

A simple ultrasonic energy assisted synthesis of β-cyclodextrin (β-CD) supported carbon nanofiber composite (CNF) and its potential application in electrochemical sensing of antibiotic nitrofurantoin (NFT) is reported. The elemental composition and surface morphology of the β-CD/CNF composite was validated through Field emission scanning electron microscopy, energy dispersive X-ray microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The uniform enfolding of hydrophilic β-CD over CNF enhance the aqueous dispersion and offer abundant active surface to the β-CD/CNF composite. Further, the electrocatalytic efficacy of the β-CD/CNF composite is utilized to fabricate an electrochemical sensor for the high sensitive quantitative detection of NFT. Under optimized analytical conditions, the sensor displays a broad working range of 0.004-308 µM and calculated detection limit of 1.8 nM, respectively. In addition, the sensor showcased a good selectivity, storage, and working stability, with amiable reproducibility. The point-of-care applicability of the sensor was demonstrated with NFT spiked human blood serum and urine sample with reliable analytical performance. The simple, cost-effective NFT sensor based on β-CD/CNF offered outstanding analytical performance in real-world samples with higher reliability.