Optical fiber peptide-sensor for ultrasensitive detection of prostate specific antigen

Abstract

We develop the first optical fiber-based peptisensor with chemiluminescent detection, and apply it for ultrasensitive detection of prostate-specific antigen (PSA), an important biomarker for early diagnosis of prostate disease. Optical fiber is used not only as the carrier of the biological recognition elements (the specific biotinylated peptides, bio-KQLKSSHC), but also for the excellent light conduction for chemiluminescence signal output. The peptisensor is easily fabricated and gold nanoparticles (AuNPs) modified with horseradish peroxidase (HRP) are employed as the signal label for chemiluminescent detection. By combining the streptavidin-biotin system and the large surface area of AuNPs, both the peptide loading amount and the chemiluminescence signal are enhanced, thus the response of the peptisensor is greatly improved with a wide linear range of 0.80 pg/mL −100 ng/mL (2.42 ×10−9-3.03 ×10−4 nmol) and a low limit-of-detection of 0.30 pg/mL (9.09 ×10−10 nmol). The HRP@AuNPs@peptide optical fiber peptisensor exhibiting good reproducibility and selectivity for PSA assays. Our study indicates that the optical fiber-based peptisensors would be of value for sensitive detection of biomarkers with advantages of low-cost, easy operation and possibly for miniaturization, thus would they have great potential application in vitro diagnosis.