title: Label-free detection of cardiac troponin I with a photonic crystal biosensor.
abstract: A biosensor has been developed with a photonic crystal structure used in a total-internal-reflection (PC-TIR) configuration for label-free detection of a cardiac biomarker: Troponin I (cTnI). In contrast to a conventional optical microcavity that has a closed structure with its cavity layer sandwiched between two high-reflection surfaces, the PC-TIR configuration creates a unique open microcavity, which allows its cavity layer (sensing layer) to be easily functionalized and directly exposed to analyte molecules for bioassays. In this study, a PC-TIR sensor has been used for the label-free measurements of cardiac biomarkers by monitoring the changes in the resonant condition of the cavity due to biomolecular binding processes. Antibodies against cTnI are immobilized on the sensor surface for specific detection of cTnI with a wide range of concentrations. Detection limit of cTnI with a concentration as low as 0.1ngmL(-1) has been achieved.
authors.affiliation: Department of Biomedical Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA.
authors.forename: Bailin
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Department of Biomedical Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA.
authors.forename: Andres W
authors.initials: AW
authors.lastname: Morales
authors.affiliation: Department of Biomedical Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA.
authors.forename: Ralph
authors.initials: R
authors.lastname: Peterson
authors.affiliation: Department of Biomedical Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA.
authors.forename: Liang
authors.initials: L
authors.lastname: Tang
authors.affiliation: Department of Biomedical Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA. Electronic address: jingyong.ye@utsa.edu.
authors.forename: Jing Yong
authors.initials: JY
authors.lastname: Ye
mesh_terms: D001681:Biological Assay / Q000295:instrumentation; D015374:Biosensing Techniques / Q000295:instrumentation*; D003460:Crystallization; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation*; D008904:Miniaturization; D017785:Photons; D012031:Refractometry / Q000295:instrumentation*; D013194:Staining and Labeling; D019210:Troponin I / Q000097:blood* / Q000737:chemistry
chemical_list: D019210:Troponin I
keywords: Bioassay; Myocardial infarction; Optical biosensor; Optical microcavity