Detection of lipoprotein-associated phospholipase A2 using a nano-iridium particle catalyst-based biosensor

The detection and quantification of lipoprotein-associated phospholipase A2 (Lp-PLA2) using an iridium-modified carbon-based biosensor was successfully accomplished in this study. The detection procedure was based on the hydrolysis of short-chain carboxylic esters; which produced as products, organic acids and alcohol. The alcohol was then oxidized by alcohol oxidase producing hydrogen peroxide, which was detected electrochemically. A methyl ester (methyl butyrate) was chosen as the substrate for this Lp-PLA2 study. The methanol produced from the methyl ester hydrolysis reaction was oxidized by alcohol oxidase, resulting in the production of hydrogen peroxide, which was quantified using the iridium-modified carbon-based biosensor. The detection of Lp-PLA2, in the concentration range 0–150 U ml−1, was established as following a linear relationship with a sensitivity of 1.45 nA U−1 in bovine serum. The effects of potential interfering species, such as uric acid (UA) and ascorbic acid (AA), are experimentally assessed.