Abstract
Prostate-specific antigen (PSA) is the best-known biomarker for early diagnosis of prostate cancer. For prostate cancer in particular, the threshold level of PSA <4.0 ng/mL in clinical samples is an important indicator. Quick and easy visual detection of the PSA level greatly helps in early detection and treatment of prostate cancer and reducing mortality. In this study, we developed optimized silica-coated silver-assembled silica nanoparticles (SiO2@Ag@SiO2 NPs) that were applied to a visual lateral flow immunoassay (LFIA) platform for PSA detection. During synthesis, the ratio of silica NPs to silver nitrate changed, and as the synthesized NPs exhibited distinct UV spectra and colors, most optimized SiO2@Ag@SiO2 NPs showed the potential for early prostate cancer diagnosis. The PSA detection limit of our LFIA platform was 1.1 ng/mL. By applying each SiO2@Ag@SiO2 NP to the visual LFIA platform, optimized SiO2@Ag@SiO2 NPs were selected in the test strip, and clinical samples from prostate cancer patients were successfully detected as the boundaries of non-specific binding were clearly seen and the level of PSA was <4 ng/mL, thus providing an avenue for quick prostate cancer diagnosis and early treatment.
Highlights
Biomarker detection facilitates early diagnosis and monitoring of disease status, such as in cancer [1]
Tetraethyl orthosilicate (TEOS), (3-mercaptopropyl)trimethoxysilane (MPTS), ethylene glycol (EG), silver nitrate (AgNO3, 99.99%), octylamine (OA), sodium silicate solution, (3-aminopropyl)triethoxysilane (APTS), succinic anhydride, N, N-diisopropylethylamine (DIEA), N-(3-dimethylaminopropyl)-N0 -ethylcarbodiimide hydrochloride (EDC), N-hydroxysulfosuccinimide sodium salt (Sulfo-NHS), 2-(N-morpholino)ethanesulfonic acid (MES) hydrate, phosphate-buffered saline (PBS, pH 7.4), TWEEN® 20, 11-mercaptoundecanoic acid (11-MUA), and ethanolamine were purchased from Sigma–Aldrich
SiO2 @Ag@SiO2 NPs for detecting specific Prostate-specific antigen (PSA) concentrations on an lateral flow immunoassay (LFIA) platform based on the pattern formed with the introduction of AgNPs
Summary
Biomarker detection facilitates early diagnosis and monitoring of disease status, such as in cancer [1]. Immunological assays have been commonly used for the detection of these biomarkers in a non- or minimally-invasive manner [3,4,5]. Typical techniques for immunological analysis include enzyme-linked immunosorbent assay (ELISA), radio immunoassay (RIA), and the fluorescent antibody (Ab) (FA) technique [6,7,8]. ELISA is a representative immunological analysis method widely used as a diagnostic tool in medicine due to its high reproducibility and strong quantitative approach [9], but it requires large amounts of samples (20–200 μL), has a lengthy analysis time (1.5–3 h), and requires expensive instrumentation for quantitative analysis [10]. An alternative to ELISA, paper-based ELISA, in which paper is used as a substrate for AB immobilization, can be performed quickly (~1 h) using a small amount of the sample (1–10 μL) and simple equipment (commercial scanners); a disadvantage is that it has a lower sensitivity than conventional
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
