Amperometric L-arginine biosensor based on a novel recombinant arginine deiminase

作者：Zhybak Mykhailo T^*; Fayura Lyubov Y; Boretsky Yuriy R; Gonchar Mykhailo V; Sibirny Andriy A; Dempsey Eithne; Turner Anthony P F; Korpan Yaroslav I^*

来源：Microchimica Acta, 2017, 184(8): 2679-2686.

DOI：10.1007/s00604-017-2290-4

• L-arginine
• Ammonium ions
• Amperometry
• Nafion
• Polyaniline
• Recombinant enzyme
• Plasma samples
• Pharmaceuticals

The authors describe an amperometric biosensor for the amino acid L-arginine (L-Arg). It is based on the use of a Nafion/Polyaniline (PANi) composite on a platinum screen-printed electrode (Pt-SPE) using a novel recombinant arginine deiminase isolated from Mycoplasma hominis. The protein was over-expressed, purified and employed as a biorecognition element of the sensor. Enzymatic hydrolysis of L-Arg leads to the formation of ammonium ions which diffuse into the Nafion/PANi layer and induce the electroreduction of PANi at a potential of -0.35 V (vs Ag/AgCl). L-Arg sensitivity is 684 +/- 32 A.M-1.m(-2), and the apparent Michaelis-Menten constant K-M(app)) is 0.31 +/- 0.05 mM. The calibration plot is linear over the range 3-200 mu M L-Arg, the limit of detection is 1 mu M, and the response time (for 90% of the total signal change to occur) is 15 s. The sensor is selective and exhibits good storage stability (> 1 month without loss in signal). The biosensor was applied to the analysis of L-Arg in pharmaceutical samples and of ammonium and L-Arg in spiked human plasma obtained from blood of healthy volunteers and those with a hepatic disorder. Data generated were found to be in good agreement with a reference fluorometric enzymatic assay.

• 出版日期2017-8