title: Silver nanoprism etching-based plasmonic ELISA for the high sensitive detection of prostate-specific antigen.
abstract: Ultrasensitive and quantitative detection using simple and low-cost assays is critical in clinical diagnostics. In this report, we developed a triangular silver nanoprism (AgNPRs) etching-based plasmonic biosensor for the detection of cancer biomarkers. The triangular AgNPRs-based plasmonic biosensor is an enzyme-linked immunosorbent assay combined with the enzyme-mediated surface plasmon resonance (SPR) of triangular AgNPRs. Triangular AgNPRs uses the immune response of prostate-specific antigen (PSA) to trigger the glucose oxidase (GOx)-catalysed oxidation of glucose (Glu), producing hydrogen peroxide. Hydrogen peroxide acts as an oxidant to etch the triangular AgNPRs into smaller spherical silver nanoparticles, which is accompanied by a substantial blueshift of the SPR peak and a colourimetric blue-to-purple change that can be observed by the naked eye. The SPR peak shift enables the quantitative assessment of PSA due to the remarkable colour change. The triangular AgNPRs-based plasmonic ELISA approach exhibited a quasilinear response to logarithmic PSA concentrations in the range of 10fg/mL to 100pg/mL with a limit of detection (LOD) of 4.1fg/mL. In addition, the LOD of PSA in this approach exceeds that of the conventional HRP-based ELISA (1.25ng/mL) approach by more than 5 orders of magnitude. Patient serum samples from 16 donors were assayed with triangular AgNPRs-based plasmonic ELISA. The results from the triangular AgNPRs-based immunoassay and the time-resolved fluorescence immunoassay showed excellent correlation, and there were no significant differences in the quantified amounts of PSA. The triangular AgNPRs-based plasmonic ELISA approach has advantages (ultrasensitive, cost-effective, ease of operation) that are expected to be of great interest in diagnostics and to be suitable for a point-of-care test.
authors.affiliation: Department of Bioengineering, Guangdong Province Key Laboratory of Molecular Immunology and Antibody Engineering, Jinan University, Guangzhou 510632, PR China.
authors.forename: Jiajie
authors.initials: J
authors.lastname: Liang
authors.affiliation: Department of Bioengineering, Guangdong Province Key Laboratory of Molecular Immunology and Antibody Engineering, Jinan University, Guangzhou 510632, PR China.
authors.forename: Cuize
authors.initials: C
authors.lastname: Yao
authors.affiliation: Department of Bioengineering, Guangdong Province Key Laboratory of Molecular Immunology and Antibody Engineering, Jinan University, Guangzhou 510632, PR China.
authors.forename: Xiuqing
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Bioengineering, Guangdong Province Key Laboratory of Molecular Immunology and Antibody Engineering, Jinan University, Guangzhou 510632, PR China.
authors.forename: Ze
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Department of Bioengineering, Guangdong Province Key Laboratory of Molecular Immunology and Antibody Engineering, Jinan University, Guangzhou 510632, PR China.
authors.forename: Caihong
authors.initials: C
authors.lastname: Huang
authors.affiliation: Department of Bioengineering, Guangdong Province Key Laboratory of Molecular Immunology and Antibody Engineering, Jinan University, Guangzhou 510632, PR China.
authors.forename: Qiangqiang
authors.initials: Q
authors.lastname: Fu
authors.affiliation: Department of Bioengineering, Guangdong Province Key Laboratory of Molecular Immunology and Antibody Engineering, Jinan University, Guangzhou 510632, PR China.
authors.forename: Caifeng
authors.initials: C
authors.lastname: Lan
authors.affiliation: Department of Laboratory Medicine, Guangdong No. 2 Provincial People's Hospital, Guangzhou 510317, PR China.
authors.forename: Donglin
authors.initials: D
authors.lastname: Cao
authors.affiliation: Department of Bioengineering, Guangdong Province Key Laboratory of Molecular Immunology and Antibody Engineering, Jinan University, Guangzhou 510632, PR China. Electronic address: tyjaq7926@163.com.
authors.forename: Yong
authors.initials: Y
authors.lastname: Tang
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D008297:Male; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis; D012031:Refractometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012834:Silver / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D014408:Biomarkers, Tumor; D012834:Silver; D017430:Prostate-Specific Antigen
keywords: Enzyme-linked immunosorbent assay; Etching; Plasmonic biosensor; Signal amplification; Silver nanoprism