A new inorganic-organic hybrid compound based on polyoxometalate and organic ligand formulated as （H2bpp）3[SiWlIO39Co]-2H20（1）[bpp=l,3-bis（4-pyridyl）propane] was hydrothermally synthesized and structurally chara...A new inorganic-organic hybrid compound based on polyoxometalate and organic ligand formulated as （H2bpp）3[SiWlIO39Co]-2H20（1）[bpp=l,3-bis（4-pyridyl）propane] was hydrothermally synthesized and structurally characterized by elemental analysis, single-crystal X-ray diffraction, IR, TG, and cyclic voltammetry. Single-crystal X-ray diffraction analysis reveals that compound 1 consists of interesting cobalt-monosubstituted POMs one dimensional chain together with protonated bpp ligands. Additionally, the polyoxoanions combined with the discrete organic substrates by hydrogen bond interactions to afford a supramolecular 3D network structure. The hybrid compound 1 was used as a bulk modifier to fabricate a three-dimensional chemically modified carbon paste electrode（1-CPE） by direct mixing. The electrochemical behavior and electrocatalysis of 1-CPE were studied in detail. The results indicate that 1-CPE has good electrocatalytic activities toward the reduction of nitrite or bromate in 1 mol/L 1-12SO4 aqueous solution. 1-CPE shows remarkable stability that can be ascribed to the insolubility of compound 1 and the supramolecular interactions existed between 1D POM anion chains and organic ligand bpp, which is very important for practical applications in electrode modification.展开更多
Electrochemical determination of paracetamol(PCT)was successfully performed using carbon paste electrodes(CPEs)modified with treated coffee husks(CHt)or cellulose powder(Ce).Scanning electron microscopy was used to ch...Electrochemical determination of paracetamol(PCT)was successfully performed using carbon paste electrodes(CPEs)modified with treated coffee husks(CHt)or cellulose powder(Ce).Scanning electron microscopy was used to characterize unmodified or modified CPEs prior to their use.The electrochemical oxidation of PCT was investigated using square wave voltammetry(SWV)and cyclic voltammetry(CV).The oxidation current density of PCT was two-fold higher with the CPE-CHt sensor and 30%higher with CPE-Ce in comparison with the unmodified CPE,and this correlated with the higher hydrophilicity of the modified electrodes.Using SWV for the electrochemical analysis of PCT,carbon paste electrode modified with raw coffee husks(CPE-CHr)showed the presence of impurities at+0.27 V/SCE,showing the interest in using pure cellulose for the present analytical application.Furthermore,CPE-Ce presented a higher real area compared to CPE-CHr,which explains the increase in the limit of saturation from 400 mg/L to 950 mg/L.The better saturation limit exhibited by CPE-Ce justifies its choice for electroanalysis of PCT in commercialized tablets.The proposed method was successfully applied in the determination of PCT in commercialized tablets(DolipraneR 500)with a recovery rate close to 100%,and no interference with the excipients contained in the tablets analyzed was observed.This novel sensor opens the way for sustainable development of electroanalytical control of drugs sold individually in developing countries.展开更多
基金Supported by the Natural Science Foundation of Liaoning Province, China(No20061073)Education Committee Foun-dation of Liaoning Province, China(No2006031)
文摘A new inorganic-organic hybrid compound based on polyoxometalate and organic ligand formulated as （H2bpp）3[SiWlIO39Co]-2H20（1）[bpp=l,3-bis（4-pyridyl）propane] was hydrothermally synthesized and structurally characterized by elemental analysis, single-crystal X-ray diffraction, IR, TG, and cyclic voltammetry. Single-crystal X-ray diffraction analysis reveals that compound 1 consists of interesting cobalt-monosubstituted POMs one dimensional chain together with protonated bpp ligands. Additionally, the polyoxoanions combined with the discrete organic substrates by hydrogen bond interactions to afford a supramolecular 3D network structure. The hybrid compound 1 was used as a bulk modifier to fabricate a three-dimensional chemically modified carbon paste electrode（1-CPE） by direct mixing. The electrochemical behavior and electrocatalysis of 1-CPE were studied in detail. The results indicate that 1-CPE has good electrocatalytic activities toward the reduction of nitrite or bromate in 1 mol/L 1-12SO4 aqueous solution. 1-CPE shows remarkable stability that can be ascribed to the insolubility of compound 1 and the supramolecular interactions existed between 1D POM anion chains and organic ligand bpp, which is very important for practical applications in electrode modification.
文摘Electrochemical determination of paracetamol(PCT)was successfully performed using carbon paste electrodes(CPEs)modified with treated coffee husks(CHt)or cellulose powder(Ce).Scanning electron microscopy was used to characterize unmodified or modified CPEs prior to their use.The electrochemical oxidation of PCT was investigated using square wave voltammetry(SWV)and cyclic voltammetry(CV).The oxidation current density of PCT was two-fold higher with the CPE-CHt sensor and 30%higher with CPE-Ce in comparison with the unmodified CPE,and this correlated with the higher hydrophilicity of the modified electrodes.Using SWV for the electrochemical analysis of PCT,carbon paste electrode modified with raw coffee husks(CPE-CHr)showed the presence of impurities at+0.27 V/SCE,showing the interest in using pure cellulose for the present analytical application.Furthermore,CPE-Ce presented a higher real area compared to CPE-CHr,which explains the increase in the limit of saturation from 400 mg/L to 950 mg/L.The better saturation limit exhibited by CPE-Ce justifies its choice for electroanalysis of PCT in commercialized tablets.The proposed method was successfully applied in the determination of PCT in commercialized tablets(DolipraneR 500)with a recovery rate close to 100%,and no interference with the excipients contained in the tablets analyzed was observed.This novel sensor opens the way for sustainable development of electroanalytical control of drugs sold individually in developing countries.
