کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1271773 | 1496926 | 2012 | 13 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: DNA/nickel oxide nanoparticles/osmium(III)-complex modified electrode toward selective oxidation of l-cysteine and simultaneous detection of l-cysteine and homocysteine DNA/nickel oxide nanoparticles/osmium(III)-complex modified electrode toward selective oxidation of l-cysteine and simultaneous detection of l-cysteine and homocysteine](/preview/png/1271773.png)
The modification of glassy carbon (GC) electrode with electrodeposited nickel oxide nanoparticles (NiOxNPs) and deoxyribonucleic acid (DNA) is utilized as a new efficient platform for entrapment of osmium (III) complex. Surface morphology and electrochemical properties of the prepared nanocomposite modified electrode (GC/DNA/NiOxNPs/Os(III)-complex) were investigated by FESEM, cyclic voltammetry and electrochemical impedance spectroscopy techniques. Cyclic voltammetric results indicated the excellent electrocatalytic activity of the resulting electrode toward oxidation of l-cysteine (CySH) at reduced overpotential (0.1 V vs. Ag/AgCl). Using chronoamperometry to CySH detection, the sensitivity and detection limit of the biosensor are obtained as 44 μA mM− 1 and 0.07 μM with a concentration range up to 1000 μM. The electrocatalytic activity of the modified electrode not only for oxidation of low molecular-mass biothiols derivatives such as, glutathione, l-cystine, l-methionine and electroactive biological species ( dopamine, uric acid, glucose) is negligible but also for very similar biothiol compound (homocysteine) no recognizable response is observed at the applied potential window. Furthermore, the simultaneous voltammetric determination of l-cysteine and homocysteine compounds without any separation or pretreatment process was reported for the first time in this work. Finally, the applicability of sensor for the analysis of CySH concentration in complex serum samples was successfully demonstrated. Highly selectivity, excellent electrocatalytic activity and stability, remarkable antifouling property toward thiols and their oxidation products, as well as the ability for simultaneous detection of l-cysteine and homocysteine are remarkably advantageous of the proposed DNA based biosensor.
► Nickel oxide nanoparticles and DNA is utilized for entrapment of osmium (III) complex.
► Redox system shows excellent catalytic activity toward oxidation of CySH.
► Nanomolar concentration of cysteine determined in the presence various redox interferences.
► Modified electrode was used for simultaneous detection of cysteine and homocysteine.
► Analysis of CySH concentration in complex serum samples was successfully demonstrated.
Journal: Bioelectrochemistry - Volume 86, August 2012, Pages 9–21