title: Colloidal-based localized surface plasmon resonance (LSPR) biosensor for the quantitative determination of stanozolol.
abstract: This work reports the systematic preparation of biosensors through the use of functionalized glass substrates, noble metal gold colloid, and measurement by localized surface plasmon resonance (LSPR). Glass substrate was modified through chemical silanization, and the density of gold colloid was carefully controlled by optimizing the conditions of silanization through the use of mixed silanes and selective mixing procedures. At this point, samples were exposed to bioreagents and changes in the shallow dielectric constant around the particles were observed by dark-field spectroscopy. Biological binding of high affinity systems (biotin/streptavidin and antigen/antibody) was subsequently investigated by optimizing coating layers, receptor concentration profiling, and finally quantitative determination of the analyte of interest, which in this case was a small organic molecule-the widely used, synthetic anabolic steroid called stanozolol. For this system, high specificity was achieved (>97%) through extensive nonspecific binding tests, with a sensitivity measurable to a level below the minimum required performance level (MRPL) as determined by standard chromatographic methods. Analytical best-fit parameters of Hillslope and regression coefficient are also commented on for the final LSPR biosensor. The LSPR biosensor showed good reproducibility (<5% RSD) and allowed for rapid preparation of calibration curves and determination of the analyte (measurement time of each sample ca. 2 min). As an alternative method for quantitative steroidal analysis, this approach significantly simplifies the detection setup while reducing the cost of analysis. In addition the system maintains comparable sensitivity to standard surface plasmon resonance methods and offers great potential for miniaturization and development of multiplexed devices.
authors: ICFO Institute of Photonic Science, Mediterranean Technology Park, 08860, Castelldefels, Spain. mark.kreuzer@icfo.es
authors: Mark P
authors: MP
authors: Kreuzer
authors: Romain
authors: R
authors: Quidant
authors: J-Pablo
authors: JP
authors: Salvador
authors: M-Pilar
authors: MP
authors: Marco
authors: Gonçal
authors: G
authors: Badenes
mesh_terms: D000906:Antibodies / Q000276:immunology; D000941:Antigens / Q000276:immunology; D015374:Biosensing Techniques / Q000379:methods*; D001710:Biotin / Q000737:chemistry; D017979:Gold Colloid / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012821:Silanes / Q000737:chemistry; D013197:Stanozolol / Q000032:analysis*; D019809:Streptavidin / Q000737:chemistry; D020349:Surface Plasmon Resonance / Q000379:methods*; D013499:Surface Properties
chemical_list: D000906:Antibodies; D000941:Antigens; D017979:Gold Colloid; D012821:Silanes; D013197:Stanozolol; D001710:Biotin; D019809:Streptavidin