Amperometric lactate biosensor for flow injection analysis based on a screen-printed carbon electrode containing Meldola's Blue-Reinecke salt, coated with lactate dehydrogenase and NAD+.
A biosensor for the measurement of lactate in serum has been developed, which is based on a screen-printed carbon electrode, modified with Meldola's Blue-Reinecke Salt (MBRS-SPCE), coated with the enzyme lactate dehydrogenase NAD(+) dependent (from Porcine heart), and NAD(+). A cellulose acetate layer was deposited on the top of the device to act as a permselective membrane. The biosensor was incorporated into a commercially available, thin-layer, amperometric flow cell operated at a potential of only +0.05 V vs. Ag/AgCl. The mobile phase consisted of 0.2 M phosphate buffer pH 10 containing 0.1 M potassium chloride solution; a flow rate of 0.8 ml min(-1) was used throughout the investigation. The biosensor response was linear over the range 0.55-10 mM lactate; the former represents the detection limit. The precision of the system was determined by carrying out 10 repeat injections of 10 mM l(+)lactic acid standard; the calculated coefficient of variation was 4.28%. It was demonstrated that this biosensor system could be applied to the direct measurement of lactate in serum without pre-treatment; therefore, this would allow high throughput-analysis, at low cost, for this clinically important analyte.
Piano
M
M
Applied Enzyme Technology Ltd., Monmouth House, Mamhilad Park, Pontypool, NP46HZ, UK.
Serban
S
S
Pittson
R
R
Drago
G A
GA
Hart
J P
JP
D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002244:Carbon / Q000737:chemistry*; D002417:Cattle; D004563:Electrochemistry; D004566:Electrodes; D017022:Flow Injection Analysis; D006863:Hydrogen-Ion Concentration; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D019344:Lactic Acid / Q000032:analysis* / Q000097:blood; D009243:NAD / Q000378:metabolism*; D010078:Oxazines / Q000737:chemistry*; D011327:Printing; D013552:Swine; D013861:Thiocyanates / Q000737:chemistry*
D010078:Oxazines; D013861:Thiocyanates; D009243:NAD; C001818:Reinecke Salt; D019344:Lactic Acid; C005559:Meldola blue; D002244:Carbon; D007770:L-Lactate Dehydrogenase