پديدآورندگان :
Mirzaei Fatemeh Department of Chemistry, Shahid Bahonar University of Kerman, Kerman, Iran / Young Research Society, Shahid Bahonar University of Kerman, Kerman, Iran , Mirzaei Mohammad fmirzaie.chem@gmail.com Department of Chemistry, Shahid Bahonar University of Kerman, Kerman, Iran; , Torkzadeh-Mahani Masoud Department of Biotechnology, Institute of Science, High Technology and Environmental Science, Graduate University of Advanced Technology, Kerman, Iran
چكيده فارسي :
Pyruvate is an important intermediate in several metabolic pathways. So, it could be indicator for intensity of circulatory disorder [1]. In this work, in order to pyruvate determination new lactate dehydrogenase (LDH) nanosensor was fabricated by using graphene oxide (GO)/AuNPa/Poly vinyl alcohol (PVA) composite. Pyruvate concentration was determined by decreasing in NADH signal according to enzymatic reaction. Due to a high surface to volume ratio and electrical conductivity of GO/AuNPs/PVA, the electrochemical signal was increased. The step by step electrode modification was confirmed by cyclic voltammetery and electrochemical impedance spectroscopy successfully. This nanobiosensor was employed for pyruvate detection by differential pals voltammetery and under optimum condition (pH= 7, 0.1 M PBS, 10 mM NADH), the detection limit of 8.69 nM with two linear range and RSD of 4.3 and 3.6% for reproducibility and repeatability was obtained. The selectivity of this method was investigated by adding ascorbic acid, citric acid and glucose in absence and presence of pyruvate and indicated they did not have significant effect on pyruvate determination. The apparent Michaelis-Menten constant () was determined 1.5 mM amperometrically. The stability of this LDH nanosensor was investigated and it showed a good stability after 15 days. LDH nanosensor was successfully applied for real sample (serume and onion) analysis and the recoveries were an interval of 93 – 104.
