A promising electrochemical microsensor was fabricated by electrochemical immobilization of DNA on a carbon fiber electrode(CFE) through an overoxidized polypyrrole(PPyox) template for simultaneous determination of se...A promising electrochemical microsensor was fabricated by electrochemical immobilization of DNA on a carbon fiber electrode(CFE) through an overoxidized polypyrrole(PPyox) template for simultaneous determination of serotonin(5-HT) and dopamine(DA). Such a nano-thickness DNA-PPyox biocomposite modification layer exhibited a superior selectivity and sensitivity towards these neuronal amines comparing with a simple PPyox or DNA coating. This microsensor gave three separated differential pulse voltammetric(DPV) peaks at 0.38, 0.20 and -0.02 V for 5-HT, DA and 25000-fold excess of ascorbic acid(AA). The utility of this composite biosensor was demonstrated by the determination of 5-HT content in healthy human blood serum and DA in its hydrochloric injection.展开更多
A highly selective and sensitive electrochemical method was developed for the detection of serotonin (5-hydroxytryptamine, 5-HT) at gold nanoflowers (Au NFs) and overoxidized polypyrrole (OPPy) modified carbon fiber m...A highly selective and sensitive electrochemical method was developed for the detection of serotonin (5-hydroxytryptamine, 5-HT) at gold nanoflowers (Au NFs) and overoxidized polypyrrole (OPPy) modified carbon fiber microelectrode (CFME). Carbon fiber was firstly modified with gold nanoflowers using electroless deposition method, and then modified with overoxidized polypyrrole using electrochemical polymerization and overoxidization to obtain OPPy/Au NFs/CFME. The obtained OPPy/Au NFs/CFME was characterized by field emission scanning electron microscopy and electrochemical techniques. It was found that the OPPy/Au NFs/CFME showed good sensitivity for the detection of 5-HT in the range of 10 nmol/L-7.0μmol/L with detection limit of 2.3 nmol/L, and negligible interferences from ascorbic acid, 5-hydroxyindole acetic acid and uric acid. The OPPy/Au NFs/CFME was successfully applied to the detection of 5-HT in human serum samples with good recovery. The work demonstrates that the electrochemical method, incorporating signal amplification of Au NFs with higher cation selection of OPPy, provides a promising tool for the detection of 5-HT in biological systems.展开更多
The voltammetric behaviour of uric acid at overoxidized polypyrrole (OPPY ) film-coated glassy carbon (GC ) electrodes was investigaied. The chemically modi- fied electrodes exhilbited an excellent permselectivity for...The voltammetric behaviour of uric acid at overoxidized polypyrrole (OPPY ) film-coated glassy carbon (GC ) electrodes was investigaied. The chemically modi- fied electrodes exhilbited an excellent permselectivity for uric acid of undissociated form in an acidic medium. The current response sensitivity of uric acid at the modi- fied electrodes was markedly increased by properly anodizing activation of underly- ing electrodes and overoxidizing treatment of polypyrrole film. The voltammetric response of uric acid at the chemically modified electrode was linearly related to itinvestigatedtion in the range of 4. 0 ×10-7 -8. 0 ×10-5 mol/L in pH 5 buffer solu- tions. Ascorbic acid in less than 150-fold excess did not interfere with the voltam- metric determination of uric acid. The proposed procedure was utilized to determine uric acicl in human urine and serum samples without any pretreatment.展开更多
文摘A promising electrochemical microsensor was fabricated by electrochemical immobilization of DNA on a carbon fiber electrode(CFE) through an overoxidized polypyrrole(PPyox) template for simultaneous determination of serotonin(5-HT) and dopamine(DA). Such a nano-thickness DNA-PPyox biocomposite modification layer exhibited a superior selectivity and sensitivity towards these neuronal amines comparing with a simple PPyox or DNA coating. This microsensor gave three separated differential pulse voltammetric(DPV) peaks at 0.38, 0.20 and -0.02 V for 5-HT, DA and 25000-fold excess of ascorbic acid(AA). The utility of this composite biosensor was demonstrated by the determination of 5-HT content in healthy human blood serum and DA in its hydrochloric injection.
基金the National Natural Science Foundation of China (Nos. 21775097 and 21804106)the China Postdoctoral Science Foundation (No. 2017M620444)the Fundamental Research Funds for the Central Universities (Nos. XJJ2018247 and GK201801006)
文摘A highly selective and sensitive electrochemical method was developed for the detection of serotonin (5-hydroxytryptamine, 5-HT) at gold nanoflowers (Au NFs) and overoxidized polypyrrole (OPPy) modified carbon fiber microelectrode (CFME). Carbon fiber was firstly modified with gold nanoflowers using electroless deposition method, and then modified with overoxidized polypyrrole using electrochemical polymerization and overoxidization to obtain OPPy/Au NFs/CFME. The obtained OPPy/Au NFs/CFME was characterized by field emission scanning electron microscopy and electrochemical techniques. It was found that the OPPy/Au NFs/CFME showed good sensitivity for the detection of 5-HT in the range of 10 nmol/L-7.0μmol/L with detection limit of 2.3 nmol/L, and negligible interferences from ascorbic acid, 5-hydroxyindole acetic acid and uric acid. The OPPy/Au NFs/CFME was successfully applied to the detection of 5-HT in human serum samples with good recovery. The work demonstrates that the electrochemical method, incorporating signal amplification of Au NFs with higher cation selection of OPPy, provides a promising tool for the detection of 5-HT in biological systems.
文摘The voltammetric behaviour of uric acid at overoxidized polypyrrole (OPPY ) film-coated glassy carbon (GC ) electrodes was investigaied. The chemically modi- fied electrodes exhilbited an excellent permselectivity for uric acid of undissociated form in an acidic medium. The current response sensitivity of uric acid at the modi- fied electrodes was markedly increased by properly anodizing activation of underly- ing electrodes and overoxidizing treatment of polypyrrole film. The voltammetric response of uric acid at the chemically modified electrode was linearly related to itinvestigatedtion in the range of 4. 0 ×10-7 -8. 0 ×10-5 mol/L in pH 5 buffer solu- tions. Ascorbic acid in less than 150-fold excess did not interfere with the voltam- metric determination of uric acid. The proposed procedure was utilized to determine uric acicl in human urine and serum samples without any pretreatment.
