Detection of alpha-methylacyl-CoA racemase (AMACR), a biomarker of prostate cancer, in patient blood samples using a nanoparticle electrochemical biosensor.
41 Background: A promising prostate cancer biomarker, alpha-methylacyl-CoA racemase (AMACR), has demonstrated the ability to distinguish cancer from healthy and benign cells with high sensitivity and specificity. However the lack of a good clinical assay has limited its translation into the clinic. Here we report on the development of a single use disposable biosensor for AMACR detection. Methods: This is a very inexpensive, small, single-use disposable sensor that requires only a drop of plasma and connects to a portable device. The biosensor utilizes the reaction of pristanic acid with a substrate that includes AMACR to produce Trans-2,3-dehydropritanayl-CoA plus H2O2. The biosensor utilizes iridium oxide nanoparticle catalyst to oxidize the H2O2 produced in the above metabolic pathway. Thus the oxidation of H2O2 yields a measurable current to quantify AMACR in the sample. This is the first in vitro assay method for AMACR based on this reaction mechanism. Results: In our study including plasma from 9 healthy males, 10 patients with high grade prostatic intraepithelial neoplasia and 5 prostate cancer patients we show 100% accuracy in separating prostate cancer patients from controls as well as those with benign prostate conditions. Conclusions: Our data provides strong evidence for the ability of this biosensor to perform as a reliable assay for prostate cancer detection and diagnosis.