1Amity Institute of Nanotechnology, Amity University, Noida 201303, Uttar Pradesh, India
2Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
3Department of Biochemistry, M. D. University, Rohtak 124001, Haryana, India
Adv. Mater. Lett., 2015, 6 (5), pp 407-413
Publication Date (Web): May 05, 2015
Copyright © IAAM-VBRI Press
An amperometric lysine biosensor was fabricated by immobilizing lysine oxidase onto core shell magnetic nanoparticles (Core–shell MNPs)/multiwalled carbon nanotube (MWCNT) layer deposited on Au electrode via carbodiimide linkage. Transmission electron microscopy (TEM) for core–shell MNPs, scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and Fourier transform impedance spectroscopy (FTIR) studies were used to characterize the modified electrode. Sensor showed optimal response within 2s at 30ºC in 0.05 M sodium phosphate buffer pH 6.0 when polarized at +0.2 V vs. Ag/AgCl. Linear working range of the biosensor was determined by 0.05 -700 μM with a detection limit of 0.05 μM. A good correlation (r = 0.98) was obtained between serum lysine levels measured by the standard HPLC method (y) and the present method (x). A number of serum substances had practically no interference. The sensor was used in 150 assays and had a storage life of 180 days at 4oC. This nanohybrid biosensor will be useful for detection of lysine in food and pharmaceutical industries.
Lysine oxidase, lysine, core&ndash,shell MNPs, multiwalled carbon nanotube.