The development of novel detection methods of pathogenic bacteria remains as anan enormous scientific challenge and a significant practical problem of big significance. We present a novel electrochemical method for rapid and analytical detection of Staphylococcus aureus in pure culture and spiked milk samples through the hydrogen peroxide consumption at a gold screen printed gold electrode (SPGE), modified with cysteine and peroxidase from guinea grass leaves (GGP). Peroxidase (POD) from guinea grass leaves, having a specific activity of 470 U mg-1, was immobilized on the surface of a gold screen printed electrode previously modified with cysteine. Cyclic voltammograms of gold electrodes modified with the peroxidase and cysteine in the presence of potassium ferrocyanide ([Fe(CN)6]3-/4- as a redox probe demonstrated an increase in the electron transfer process compared to the gold bare electrode. The screen printed gold modified electrode exhibits a good electrocatalytic response towards reduction of hydrogen peroxide. A constant hydrogen peroxide concentration of 1x10-6 M was added to the culture medium and the decrease in the reduction current of H2O2 at -780 mV consumed by catalase from S. aureus was measured. Our modified electrode has been proven to be able to sense S. aureus in a range concentration between 3x102 and 3x108 cfu mL-1 with a detection limit of 102 cfu ml-1. The SPGE modified with GGP exhibited good selectivity and sensitivity and is expected to be used in samples contaminated with foodborne pathogens.

The text above was approved for publishing by the original author.

Previous       Next

Try for free

Please enter your message
Please choose what language to correct

Check out our Wordpress proofreading plugin!

eAngel.me

eAngel.me is a human proofreading service that enables you to correct your texts by live professionals in minutes.