A reagentless, disposable biosensor for lactic acid based on a screen-printed carbon electrode containing Meldola's Blue and coated with lactate dehydrogenase, NAD+ and cellulose acetate

✍ Scribed by Steven D. Sprules; John P. Hart; Stephen A. Wring; Robin Pittson

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 547 KB
• Volume: 304
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(94)00565-4

✦ Synopsis

A disposable amperometric biosensor for lactic acid has been constructed based on the immobilisation of the enzyme L-lactate dehydrogenase (LDH) and its cofactor nicotinamide adenine dinucleotide (NAD) using a cellulose acetate (CA) membrane cast in situ. These components were deposited onto a screen-printed carbon electrode containing 2% Meldola's Blue (by weight of carbon). Sensor construction was optimised, the final biosensor contained 10 units of LDH, 60 pg of NAD+ and used a membrane cast from a 1% CA solution. The optimum solution for lactate measurement was found to consist of 0.5 mol dmP3 phosphate buffer, pH 8. The optimum temperature was 32°C. The relative standard deviation for a single batch of electrodes was found to be 8.7%.