Browsing by Author "Mounesh"

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    Electrochemical, Ultrasensitive, and Selective Detection of Nitrite and H2O2: Novel Macrostructured Phthalocyanine with Composite MWCNTs on a Modified GCE
    (2023) Mounesh; Manriquez, Juan. M.; Reddy, K. R. Venugopala; Shilpa, K. G.; Nagaraja, Bhari Mallanna
    In the current study, the synthesis of tetra-4-(2methoxyphenoxy) carboxamide cobalt(II) amide-bridged phthalocyanine (CoTMePhCAPc) is described, as well as its characterization by Fourier transform infrared (FT-IR), UV-visible, and mass spectroscopy; powder X-ray diffraction (PXRD); thermogravimetric analysis (TGA); scanning electron microscopy (SEM); and electrochemistry. Sensing of nitrite (NO2-) and hydrogen peroxide (H2O2) simultaneously was done on CoTMePhCAPc with the composite multiwalled carbon nanotube (MWCNT)modified glassy carbon electrode (CoTMePhCAPc/MWCNT/ GCE) in the range of linear absorption (NO2- and H2O2: CV 50- 750, differential pulse voltammetry (DPV) 50-750, CA 50-500 nmol L-1), lower detection limit (NO2- and H2O2: CV 10.5 and 12.5, DPV 10.5 and 11.2, CA 6.0 and 5.5 nmol L-1), and sensitivity (NO2- and H2O2: CV 0.379 and 0.529, DPV 0.043 and 0.049, CA 0.033 and 0.040 mu A nM-1 cm-2). The composite electrode exhibits improved electrocatalytic behavior compared to modified electrodes for nitrite and H2O2. The CoTMePhCAPc/MWCNT/GCE sensor displays good selectivity even in the presence of an excess of interfering metal ions and biomolecules at the applied potentials of +400 mV (nitrite) and -400 mV (H2O2). Moreover, the fabricated sensor was studied with various phosphate-buffered saline (PBS) (pH 5-9) electrolyte solutions. The unknown H2O2 concentration in blood samples and apple juice and nitrite concentration in drinking water and butter leaf lettuce were all measured using the usual addition method. Docking analysis clearly indicates that the ligand shows excellent inhibition activity toward the three subjected protein molecules.
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    Novel Schiff base iron(ii) phthalocyanine with composite MWCNTs on modified GCE: electrochemical sensor development for paracetamol
    (2022) Mounesh; Reddy, K. R. Venugopala; Yuvaraja, D.; Manriquez, Juan M.; Lokesh, K. S.; Amshumali, M. K.
    The synthesis and characterization of novel peripherally tetra-substituted Schiff base iron(ii) phthalocyanines (iron(ii) (2Z)-2-(3-chlorobenzylidene)hydrazinecarbothiocarboxamide phthalocyanine (FeTClBCTCAPc)) are described for the first time in this study. The Schiff base ligand and FeTClBCTCAPc complex are characterized by a combination of IR, H-1 NMR, mass spectroscopy, XRD, TGA and UV-vis spectroscopy techniques. The stepwise fabrication process of the FeTClBCTCAPc@GC electrode with composite MWCNTs and its electrochemical sensing performance towards paracetamol (PA) was evaluated using cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CA) and differential pulse voltammetry (DPV). Compared with the MWCNT-modified electrode, the FeTClBCTCAPc@MWCNTs/GC electrode shows a better electrocatalytic activity for the oxidation of PA with lower oxidation potential and larger peak current, so the FeTClBCTCAPc@MWCNTs/GC electrode nanocomposite can be used as an enhanced sensing platform for the electrochemical determination of PA. The kinetic parameters of PA electro-oxidation at FeTClBCTCAPc@MWCNTs/GC electrodes were studied in detail, and the determination conditions were optimized. Under the optimal conditions, the oxidation peak current is linear to the PA concentration in the range (detection limit) 50-900 nM (18.5 nM) for CA, 50-500 nM (20.5 nM) for CV, 50-500 nM (15 nM) for DPV, and 50-500 nM (15.5 nM) for LSV. Based on the high sensitivity, stability and good selectivity of the FeTClBCTCAPc@MWCNTs/GC electrode, the proposed method was successfully applied to the determination of PA in commercial tablet samples, and the satisfactory results confirm the applicability of this sensor in practical analysis.