Dual-biomarker-based logic-controlled electrochemical diagnosis for prostate cancers

• Employing PSA and survivin mRNA as dual-biomarkers in prostate cancer detection.
• Nano-structured gold electrode and direct electrochemical output.
• Logic gate of “AND” mode greatly reduced the possibility of false-positive assay.

As single biomarker often has inadequate predictive value in clinical examination, we designed a dual-biomarker “AND” logic device that defines the concentration of prostate-specific antigen (PSA) and survivin mRNA as inputs and the increase in faradaic current from intercalation agent Co(phen)33 + as output for prostate cancer (CaP) diagnosis on Au nano-film covered gold electrode surfaces. Primary capture antibody (Ab1) was first immobilized on AuNP electrode, then while both PSA and survivin mRNA exist, current of Co(phen)33 + observably increased due to the formation of dsDNA structure between survivin antisensoligonucleotide connected secondary detection antibody (Ab2) and survivin mRNA. And when one of the two biomarkers was absent, no obvious current increment was found. Thus the designed “AND” logic gate greatly reduced the possibility of false-positive assay from non-cancerous prostate diseases such as prostatic hyperplasia and prostatitis in diagnosis of CaPs.