Flow injection chemiluminescence determination of naproxen based on KMnO4–Na2SO3 reaction in neutral aqueous medium

Electrochemical Sensor Based on Ni-Co Layered Double Hydroxide Hollow Nanostructures for Ultrasensitive Detection of Sumatriptan and Naproxen

In this work, Ni-Co layered double hydroxide (Ni-Co LDH) hollow nanostructures were synthesized and characterized by X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), and Fourier-transform infrared spectroscopy (FT-IR) techniques. A screen-printed electrode (SPE) surface was modified with as-fabricated Ni-Co LDHs to achieve a new sensing platform for determination of sumatriptan. The electrochemical behavior of the Ni-Co LDH-modified SPE (Ni-CO LDH/SPE) for sumatriptan determination was investigated using voltammetric methods. Compared with bare SPE, the presence of Ni-Co LDH was effective in the enhancement of electron transport rate between the electrode and analyte, as well as in the significant reduction of the overpotential of sumatriptan oxidation. Differential pulse voltammetry (DPV) was applied to perform a quantitative analysis of sumatriptan. The linearity range was found to be between 0.01 and 435.0 μM. The limits of detection (LOD) and sensitivity were 0.002 ± 0.0001 μM and 0.1017 ± 0.0001 μA/μM, respectively. In addition, the performance of the Ni-CO LDH/SPE for the determination of sumatriptan in the presence of naproxen was studied. Simultaneous analysis of sumatriptan with naproxen showed well-separated peaks leading to a quick and selective analysis of sumatriptan. Furthermore, the practical applicability of the prepared Ni-CO LDH/SPE sensor was examined in pharmaceutical and biological samples with satisfactory recovery results.

Determination of thiourea by terbium (III)/ prulifloxacin sensitized potassium permanganate-sulfite chemiluminescence with quenching method

Based on the thiourea quenching of the chemiluminescence of Tb³⁺/ prulifloxacin (PUFX) sensitized KMnO₄-Na₂SO₃ system, a convenient and rapid chemiluminescence method for the determination of thiourea was proposed. The reaction between KMnO₄ and Na₂SO₃ brought only weak chemiluminescence, but the chemiluminescence increased sharply in the presence of sensitizer Tb³⁺/ PUFX. Addition of thiourea can prevent the reaction between KMnO₄ and Na₂SO₃, thus the chemiluminescence intensity was significantly decreased. Under the optimum conditions, the calibration graphs for thiourea were linear in the range of 1.0 × 10^-7 to 4.0 × 10^-5 mol•L^-1. The limit of detection was 6.4 × 10^-8 mol•L^-1. The method was applied satisfactorily to the determination of thiourea in tap water, lake water and rice noodles and the spiked recoveries were between 104.7 ~ 113.4%. The possible mechanism of sensitization and quenching was also proposed.

Voltammetric detection of sumatriptan in the presence of naproxen using Fe3O4@ZIF-8 nanoparticles modified screen printed graphite electrode

A novel electrochemical sensing platform was designed and prepared for the simultaneous detection of sumatriptan and naproxen by exploiting the prowess of the Fe₃O₄@ZIF-8 nanoparticles (NPs); as-synthesized Fe₃O₄@ZIF-8 NPs were characterized by energy-dispersive X-ray spectroscopy, fourier transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy (FESEM), transmission electron microscopy and thermal gravimetric analysis. The immobilized Fe₃O₄@ZIF-8 NPs on a screen printed graphite electrode (SPGE) was evaluated electrochemically via cyclic voltammetry, linear sweep voltammetry, and differential pulse voltammetry as well as chronoamprometery means; Fe₃O₄@ZIF-8/SPGE exhibited good sensing performance for sumatriptan in a range of 0.035–475.0 µM with detection limit of 0.012 µM. Also, Fe₃O₄@ZIF-8/SPGE exhibited good sensing performance for naproxen in a range of 0.1–700.0 µM with detection limit of 0.03 µM. The modified electrode showed two separate oxidative peaks at 620 mV for sumatriptan and at 830 mV for naproxen with a peak potential separation of 210 mV which was large enough to detect the two drugs simultaneously besides being stable in the long-run with considerable reproducibility. Real sample analyses were carried out to identify the function of fabricated electrode in sensing applications wherein trace amounts of sumatriptan and naproxen could be identified in these samples.

Determination of dihydralazine based on chemiluminescence resonance energy transfer of hollow carbon nanodots

The famous weak chemiluminescence (CL) system of potassium permanganate and sodium bisulfite (KMnO₄-HSO₃^-) was enhanced by the hollow fluorescent carbon nanodots (HCNs). The investigation of mechanism revealed that the enhanced CL was induced by the excited-state HCNs (HCNs^⁎), which could be produced from the electron-transfer annihilation of positively charged HCNs (HCNs⁺) and negatively charged HCNs (HCNs^-) as well as by CL resonance energy transfer (CRET) from excited SO₂ (SO₂^⁎)/¹O₂ to HCNs. The dihydralazine sulfate (DHZS) had a diminishing effect on the CL of HCNs-KMnO₄-HSO₃^- system due to the competitive consumption of O₂^-. Under the optimal conditions, the reduced CL signal with the concentration of DHZS was linear in the range of 1.0×10^-7-7.0×10^-5mol/L with a detection limit of 3.0×10^-8mol/L. The relative standard deviation for seven repeated determination of 5.0×10^-6mol/L DHZS was 2.1%. The established method was applied to the determination of DHZS in pharmaceutical preparations, human urine and plasma samples with good precision and accuracy.

Bisulfite induced chemiluminescence of g-C3N4 nanosheets and enhanced by metal ions

In this work, a novel chemiluminescence (CL) phenomenon was found: a g-C3N4 nanosheets suspension was mixed with NaHSO3 solution directly to produce luminescence, and the intensity of luminescence could be obviously enhanced by some metal ions, which was distinctly different from the phenomenon that Cu(2+) ions can quench the fluorescence of g-C3N4 nanosheets as reported before.

Carbon nitride quantum dot-based chemiluminescence resonance energy transfer for iodide ion sensing

Schematic illustration of the CL process and mechanism of Ce(iv)–sulfite and g-CNQDs–Ce(iv)–sulfite system.

Flow injection chemiluminescence determination of loxoprofen and naproxen with the acidic permanganate-sulfite system

A novel flow injection chemiluminescence (CL) method for the determination of loxoprofen and naproxen was proposed based on the CL system of KMnO₄, and Na₂SO₃ in acid media. The CL intensity of KMnO₄-Na₂SO₃ was greatly enhaneed in the presence of loxoprofen and naproxen. The mechanism of the CL reaction was studied by the kinetic proecss and UV-vis absorption and the conditions were optimized. Under optimized conditions, the CL intensity was linear with loxoprofen and naproxen concentration in the range of 7.0 × 10⁻⁸ – 1.0 × 10⁻⁵ g/mL and 2.0 × 10⁻⁷ – 4.0 × 10⁻⁶ g/mL with the detection limit of 2.0 × 10⁻⁸ g/mL and 3.0 × 10⁻⁸ g/mL (S/N = 3), respectively. Thc relative standard deviations were 2.39% and 1.37% for 5.0 × 10⁻⁷ g/mL naproxen and 5.0 × 10⁻⁷ g/mL loxoprofen (n = 10), respectively. The proposed method was satisfactorily applied to thc determination of loxoprofen and naproxen in pharmaceutical preparations.

Flow injection determination of benzhexol based on its sensitizing effect on the chemiluminescent reaction of Ce(IV)-sulfite

In this paper, a novel chemiluminescent (CL) method for the determination of benzhexol has been developed by combining the flow injection technique and its sensitizing effect on the weak CL reaction between sulfite and acidic cerium(IV). A mechanism for the CL reaction has been proposed on the basis of CL spectra. Under the optimized conditions, the proposed method allows the measurement of benzhexol hydrochloride over the range 0.1-10 microg/mL with a correlation coefficient of 0.9992 (n = 8), a detection limit of 0.02 microg/mL (3sigma), and a relative standard deviation for 2.0 microg/mL benzhexol (n = 11) of 1.65%. The utility of this method was demonstrated by determining benzhexol hydrochloride in tablets.

Acidic potassium permanganate as a chemiluminescence reagent—A review

A critical and comprehensive review of acidic potassium permanganate chemiluminescence is presented. This includes discussion on reaction conditions, the influence of enhancers such as polyphosphates, formaldehyde and sulfite, the relationship between analyte structure and chemiluminescence intensity, and the application of this chemistry to determine a wide variety of compounds, such as pharmaceuticals, biomolecules, antioxidants, illicit drugs, pesticides and pollutants. Previous proposals for the nature of the emitting species are re-evaluated in light of recent evidence.