title: Dual signal amplification of surface plasmon resonance imaging for sensitive immunoassay of tumor marker.
abstract: Surface plasmon resonance imaging (SPRi) is an intriguing technique for immunoassay with the inherent advantages of being high throughput, real time, and label free, but its sensitivity needs essential improvement for practical applications. Here, we report a dual signal amplification strategy using functional gold nanoparticles (AuNPs) followed by on-chip atom transfer radical polymerization (ATRP) for sensitive SPRi immunoassay of tumor biomarker in human serum. The AuNPs are grafted with an initiator of ATRP as well as a recognition antibody, where the antibody directs the specific binding of functional AuNPs onto the SPRi sensing surface to form immunocomplexes for first signal amplification and the initiator allows for on-chip ATRP of 2-hydroxyethyl methacrylate (HEMA) from the AuNPs to further enhance the SPRi signal. High sensitivity and broad dynamic range are achieved with this dual signal amplification strategy for detection of a model tumor marker, α-fetoprotein (AFP), in 10% human serum.
authors.affiliation: Institute for Clean Energy and Advanced Materials, Faculty of Materials and Energy, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Southwest University, Chongqing 400715, China; Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Wuhan University, Wuhan 430072, China. Electronic address: whhu@swu.edu.cn.
authors.forename: Weihua
authors.initials: W
authors.lastname: Hu
authors.affiliation: Institute for Clean Energy and Advanced Materials, Faculty of Materials and Energy, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Southwest University, Chongqing 400715, China.
authors.forename: Hongming
authors.initials: H
authors.lastname: Chen
authors.affiliation: Institute for Clean Energy and Advanced Materials, Faculty of Materials and Energy, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Southwest University, Chongqing 400715, China.
authors.forename: Zhuanzhuan
authors.initials: Z
authors.lastname: Shi
authors.affiliation: Institute for Clean Energy and Advanced Materials, Faculty of Materials and Energy, Southwest University, Chongqing 400715, China; Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Southwest University, Chongqing 400715, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Yu
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood* / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D006046:Gold / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D053768:Metal Nanoparticles / Q000737:chemistry; D010316:Particle Size; D058105:Polymerization; D020349:Surface Plasmon Resonance; D013499:Surface Properties; D000509:alpha-Fetoproteins / Q000032:analysis* / Q000276:immunology
chemical_list: D014408:Biomarkers, Tumor; D000509:alpha-Fetoproteins; D006046:Gold
keywords: Atom transfer radical polymerization; Gold nanoparticle; Signal amplification; Surface plasmon resonance imaging (SPRi); Tumor marker