Microfluidic electrochemical sensors for early detection of prostate cancer
By integrating multiple molecular biology assay steps on a single microfluidic platform, we aim to detect the activity of telomerase, an enzyme upregulated in prostate cancer cells. This will hopefully provide detection of prostate cancer than currently possible, and demonstrate better specificity for cancer than prostate-specific antigen (PSA) tests.
We are fabricating microelectrodes of gold and platinum on glass substrates. Through immobilization of single-stranded probe DNA containing an electrochemical tag on these electrodes, we are able to measure DNA hybridization to complementary DNA at levels to low nM concentrations. Telomerase, an RNA-dependent enzyme responsible for extending the telomeres (the ends of chromosomes), acts by adding repeats of a 4-bp sequence to the end of specific oligonucleotides. We can detect this extension activity by amplifying the result of the extension reaction on chip and then probing for the amplified product using our electrochemical sensors.