title: An enhanced LSPR fiber-optic nanoprobe for ultrasensitive detection of protein biomarkers.
abstract: A miniaturized, localized surface plasmon resonance (LSPR)-coupled fiber-optic (FO) nanoprobe is reported as a biosensor that is capable of label-free, sensitive detection of a cancer protein biomarker, free prostate specific antigen (f-PSA). The biosensor is based on the LSPR at the reusable dielectric-metallic hybrid interface with a robust, gold nano-disk array at the fiber end facet that is directly fabricated using EBL and metal lift-off process. The f-PSA has been detected with a mouse anti-human PSA monoclonal antibody (mAb) as a specific receptor linked with a self-assembled monolayer at the LSPR-FO facet surfaces. Experimental investigation and data analysis found near field refractive index (RI) sensitivity at ~226 nm/RIU with current LSPR-FO nanoprobe, and demonstrated the lowest limit of detection (LOD) at 100 fg/mL (~3 fM) of f-PSA in PBS solutions. The control experimentation using 5mg/mL bovine serum albumin in PBS and nonspecific surface test shows the excellent specificity and selectivity in the detection of f-PSA in PBS. These results present important progress towards a miniaturized, multifunctional fiber-optic technology that integrates informational communication and sensing function for developing a high performance, label-free, point-of-care (POC) device.
authors.affiliation: Department of Biological Science, University of Alabama at Huntsville, Huntsville, AL 35899, USA.
authors.forename: Mollye
authors.initials: M
authors.lastname: Sanders
authors.affiliation: Center for Applied Optics, University of Alabama at Huntsville, Huntsville, AL 35899, USA. Electronic address: liny@uah.edu.
authors.forename: Yongbin
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, Greensboro, NC 27401, USA. Electronic address: j_wei@uncg.edu.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Wei
authors.affiliation: Department of Biological Science, University of Alabama at Huntsville, Huntsville, AL 35899, USA.
authors.forename: Taylor
authors.initials: T
authors.lastname: Bono
authors.affiliation: Center for Applied Optics, University of Alabama at Huntsville, Huntsville, AL 35899, USA; Department of Electrical and Computer Engineering, University of Alabama at Huntsville, Huntsville, AL 35899, USA.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Lindquist
mesh_terms: D004867:Equipment Design; D005336:Fiber Optic Technology / Q000295:instrumentation*; D006046:Gold / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D049329:Nanostructures / Q000737:chemistry; D019095:Point-of-Care Systems; D017430:Prostate-Specific Antigen / Q000032:analysis*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D006046:Gold; D017430:Prostate-Specific Antigen
keywords: Au nanodisk array; Fiber optics; Localized surface plasmon resonance; Nanofabrication; Protein biomarker biosensors; Signal transduction