title: Novel U-bent fiber optic probe for localized surface plasmon resonance based biosensor.
abstract: The aim of this study is to develop an optical absorbance based biosensor suitable for wide scale use in resource-poor locales. A sensor for sensitive measurement of refractive index (RI) with the help of optical absorbance properties of gold nanoparticles (GNP) coupled to an efficient optical transducer in the form of a U-bent fiber optic probe is described. A U-bent probe was fabricated by a simple procedure. The absorbance due to the localized surface plasmon resonance (LSPR) of fiber-bound GNP was found to be linear to refractive index changes between 1.33 and 1.35. A U-bent probe of 200 microm diameter with a bend radius of 0.75 mm gave rise to a sensitivity of 35 DeltaA/RIU at 540 nm. The resolution of the sensor probe was 3.8x10(-5) RIU. Label-free biosensing was demonstrated using these probes with the help of IgG-anti IgG as bioreceptor-analyte pair.
authors.affiliation: School of Biosciences and Bioengineering, IIT Bombay, Mumbai 400076, India.
authors.forename: V V R
authors.initials: VV
authors.lastname: Sai
authors.forename: Tapanendu
authors.initials: T
authors.lastname: Kundu
authors.forename: Soumyo
authors.initials: S
authors.lastname: Mukherji
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D006046:Gold / Q000737:chemistry*; D006801:Humans; D055767:Immobilized Proteins / Q000032:analysis / Q000276:immunology; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods; D007074:Immunoglobulin G / Q000032:analysis / Q000276:immunology; D053768:Metal Nanoparticles / Q000737:chemistry*; D055100:Optical Fibers; D012031:Refractometry / Q000295:instrumentation / Q000379:methods*; D012680:Sensitivity and Specificity; D013053:Spectrophotometry; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D055767:Immobilized Proteins; D007074:Immunoglobulin G; D006046:Gold