Label-free plasmonic immunosensor for cortisol detection in a D-shaped optical fiber

• DOI: 10.1364/boe.456253
• Publication Date: 2022-03-30T15:00:30Z
• Authors: Maria S. Soares; Luís C. B. Silva; Miguel Vidal; Médéric Loyez; Margarida Facão; Christophe Cauche...; Marcelo E. V. Seg...; Florinda M. Costa; Cátia Leitão; Sónia O. Pereira; Nuno F. Santos; Carlos A. F. Marques
• Keywords: 0202 electrical engineering, electronic engineering, information engineering; 02 engineering and technology

Measuring cortisol levels as a stress biomarker is essential in many medical conditions associated with high risk of metabolic syndromes such anxiety and cardiovascular diseases, among others. One technology that has growing interest recent years fiber optic biosensors enable ultrasensitive detection. Such allied progress being achieved basic interrogation, accuracy improvements, novel applications. The development improved monitoring, simplified manufacturing process, reproducibility, low cost, are challenges these sensing mechanisms still face, for which solutions needed. In this paper, comprehensive characterization D-shaped immunosensor detection based on surface plasmon resonance (SPR) enabled by gold coating reported. Specifically, the sensor instrumentation fabrication processes discussed detail, simulation its complete mathematical formalism also presented. Moreover, experimental tests were performed range 0.01 to 100 ng/mL, attaining logarithmic sensitivity 0.65 ± 0.02 nm/log(ng/mL) limit (LOD) 1.46 ng/mL. Additionally, an investigation signal processing discussed, main issues addressed order highlight best way extract information from spectra measured sensor.