title: Electrochemical assay for the determination of nitric oxide metabolites using copper(II) chlorophyllin modified screen printed electrodes.
abstract: This work presents a novel electrochemical assay for the collective measurement of nitric oxide (NO) and its metabolites nitrite (NO2(-)) and nitrate (NO3(-)) in volume miniaturized sample at low cost using copper(II) chlorophyllin (CuCP) modified sensor electrode. Zinc oxide (ZnO) incorporated screen printed carbon electrode (SPCE) was used as a host matrix for the immobilization of CuCP. The morphological changes of the ZnO and CuCP modified electrodes were investigated using scanning electron microscopy. The electrochemical characterization of CuCP-ZnO-SPCE exhibited the characteristic quasi-reversible redox peaks at the potential +0.06 V versus Ag/AgCl. This biosensor electrode showed a wide linear range of response over NO concentrations from 200 nM to 500 μM with a detection limit of 100 nM and sensitivity of 85.4 nA μM(-1). Furthermore, NO2(-) measurement showed linearity of 100 nM to 1mM with a detection limit of 100 nM for NO2(-) and sensitivity of 96.4 nA μM(-1). Then, the concentration of NO3(-) was measured after its enzymatic conversion into NO2(-). Using this assay, the concentrations of NO, NO2(-), and NO3(-) present in human plasma samples before and after beetroot supplement were estimated using suitable membrane coated CuCP-ZnO-SPCE and validated with the standard Griess method.
authors.affiliation: Biomedical Research Laboratory, Department of Chemistry, VHNSN College (Autonomous), Virudhunagar 626001, Tamil Nadu, India.
authors.forename: Murugesan
authors.initials: M
authors.lastname: Balamurugan
authors.affiliation: Biomedical Research Laboratory, Department of Chemistry, VHNSN College (Autonomous), Virudhunagar 626001, Tamil Nadu, India.
authors.forename: Thangamuthu
authors.initials: T
authors.lastname: Madasamy
authors.affiliation: Biomedical Research Laboratory, Department of Chemistry, VHNSN College (Autonomous), Virudhunagar 626001, Tamil Nadu, India.
authors.forename: Manickam
authors.initials: M
authors.lastname: Pandiaraj
authors.affiliation: Peptide and Proteomics Division, Defence Institute of Physiology and Allied Sciences (DIPAS), Defence Research and Development Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India.
authors.forename: Kalpana
authors.initials: K
authors.lastname: Bhargava
authors.affiliation: Peptide and Proteomics Division, Defence Institute of Physiology and Allied Sciences (DIPAS), Defence Research and Development Organization (DRDO), Lucknow Road, Timarpur, Delhi 110054, India.
authors.forename: Niroj Kumar
authors.initials: NK
authors.lastname: Sethy
authors.affiliation: Biomedical Research Laboratory, Department of Chemistry, VHNSN College (Autonomous), Virudhunagar 626001, Tamil Nadu, India. Electronic address: ckaru2000@gmail.com.
authors.forename: Chandran
authors.initials: C
authors.lastname: Karunakaran
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation; D002735:Chlorophyllides / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D006801:Humans; D057230:Limit of Detection; D009566:Nitrates / Q000097:blood*; D009569:Nitric Oxide / Q000097:blood*; D009573:Nitrites / Q000097:blood*
chemical_list: D002735:Chlorophyllides; D009566:Nitrates; D009573:Nitrites; D009569:Nitric Oxide; D003300:Copper; C007020:chlorophyllin
keywords: Copper(II) chlorophyllin; Electrochemical assay; Nitrate; Nitric oxide; Nitrite; Screen printed carbon electrode