title: Enhanced detection sensitivity of prostate-specific antigen via PSA-conjugated gold nanoparticles based on localized surface plasmon resonance: GNP-coated anti-PSA/LSPR as a novel approach for the identification of prostate anomalies.
abstract: Prostate-specific antigen (PSA) is used to screen for prostate disease, although it has several limitations in its application as an organ-specific or cancer-specific marker. Furthermore, a highly specific/sensitive and/or label-free identification of PSA still remains a challenge in the diagnosis of prostate anomalies. We aimed to develop a gold nanoparticle (GNP)-conjugated anti-PSA antibody-based localized surface plasmon resonance (LSPR) as a novel approach to detect prostatic disease. A total of 25 nm colloidal gold particles were prepared followed by conjugation with anti-PSA pAb (GNPs-PSA pAb). LSPR was used to monitor the absorption changes of the aggregation of the particles. The size, shape and stability of the GNP-anti-PSA were evaluated by dynamic light scattering transmission electron microscopy (TEM) and zetasizer. The GNPs-conjugated PSA-pAb was successfully synthesized and subsequently characterized using ultraviolet absorption spectroscopy and TEM to determine the size distribution, crystallinity and stability of the particles (for example, stability of GNP: 443 mV). To increase the stability of the particles, we pegylated GNPs using an N-(3-dimethylaminopropyl)-N*-ethylcarbodiimide hydrochloride (EDC)/N-hydroxylsuccinimide (NHS) linker (for example, stability of GNP after pegylation: 272 mV). We found a significant increase in the absorbance and intensity of the particles with extinction peak at 545/2 nm, which was shifted by ~1 nm after conjugation. To illustrate the potential of the GNPs-PSA pAb to bind specifically to PSA, LSPR was used. We found that the extinction peak shifted 3 nm for a solution of 100 nM unlabeled antigen. In summary, we have established a novel approach for improving the efficacy/sensitivity of PSA in the assessment of prostate disease, supporting further investigation on the diagnostic value of GNP-conjugated anti-PSA/LSPR for the detection of prostate cancer.
authors.affiliation: Immunology Research Center, Iran University of Medical Sciences, Tehran, Iran.|Department of Immunology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
authors.forename: M H
authors.initials: MH
authors.lastname: Jazayeri
authors.affiliation: Physiology Research Center and Department of Physiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: H
authors.initials: H
authors.lastname: Amani
authors.affiliation: Iranian Blood Transfusion Organization, Tehran, Iran.
authors.forename: A A
authors.initials: AA
authors.lastname: Pourfatollah
authors.affiliation: Department of Modern Sciences and Technologies, Molecular Medicine Group, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: A
authors.initials: A
authors.lastname: Avan
authors.affiliation: Division of Medical Education, Brighton & Sussex Medical School, Falmer, Brighton, UK.
authors.forename: G A
authors.initials: GA
authors.lastname: Ferns
authors.affiliation: Physiology Research Center and Department of Physiology, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: H
authors.initials: H
authors.lastname: Pazoki-Toroudi
mesh_terms: D003102:Colloids / Q000737:chemistry; D055088:Early Detection of Cancer; D006046:Gold / Q000737:chemistry*; D006801:Humans; D008297:Male; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000188:drug therapy; D013056:Spectrophotometry, Ultraviolet; D020349:Surface Plasmon Resonance
chemical_list: D003102:Colloids; D006046:Gold; D017430:Prostate-Specific Antigen