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[EN] Porous materials have become one of the best options for the development of optical sensors, since they maximize the interaction between the optical field and the target substances, which boosts the sensitivity. In this work, we propose the use of a readily available mesoporous material for the development of such sensors: commercial polycarbonate track-etched membranes. In order to demonstrate their utility for this purpose, we firstly characterized their optical response in the near-infrared range. This response is an interference fringe pattern, characteristic of a Fabry¿Pérot interferometer, which is an optical device typically used for sensing purposes. Afterwards, several refractive index sensing experiments were performed by placing different concentrations of ethanol solution on the polycarbonate track-etched membranes. As a result, a sensitivity value of around 56 nm/RIU was obtained and the reusability of the substrate was demonstrated. These results pave the way for the development of optical porous sensors with such easily available mesoporous material. ; This research was funded by the Spanish Government through grant TEC2015-63838-C3-1-R-OPTONANOSENS and the Universitat Politecnica de Valencia through grants PAID-01-17. ; Martinez-Perez, P.; García-Rupérez, J. (2019). Commercial polycarbonate track-etched membranes as substrates for low-cost optical sensors. Beilstein Journal of Nanotechnology. 10:677-683. https://doi.org/10.3762/bjnano.10.67 ; S ; 677 ; 683 ; 10 ; Ruiz-Tórtola, Á., Prats-Quílez, F., González-Lucas, D., Bañuls, M.-J., Maquieira, Á., Wheeler, G., … García-Rupérez, J. (2018). Experimental study of the evanescent-wave photonic sensors response in presence of molecular beacon conformational changes. Journal of Biophotonics, 11(10), e201800030. doi:10.1002/jbio.201800030 ; Caroselli, R., Martín Sánchez, D., Ponce Alcántara, S., Prats Quilez, F., Torrijos Morán, L., & García-Rupérez, J. (2017). Real-Time and In-Flow Sensing Using a High Sensitivity Porous Silicon ...

[EN] Tuning the pore diameter of porous silicon films is essential for some applications such as biosensing, where the pore size can be used for filtering analytes or to control the biofunctionalization of its walls. However, macropore (>50nm) formation on p-type silicon is not yet fully controlled due to its strong dependence on resistivity. Electrochemical etching of heavily doped p-type silicon usually forms micropores ( 5nm), but it has been found that bigger sizes can be achieved by adding an organic solvent to the electrolyte. In this work, we compare the results obtained when adding dimethylformamide (DMF) and dimethylsulfoxide (DMSO) to the electrolyte as well as the effect of a post-treatment of the sample with potasium hydroxide (KOH) and sodium hydroxide (NaOH) for macropore formation in p-type silicon with resistivities between 0.001 and 10ohm· cm, achieving pore sizes from 5 to 100nm. ; The authors acknowledge the funding from the Spanish government through the project TEC2015-63838-C3-1-R-OPTONANOSENS. ; Martín-Sánchez, D.; Ponce-Alcántara, S.; Martinez-Perez, P.; García-Rupérez, J. (2019). Macropore Formation and Pore Morphology Characterization of Heavily Doped p-Type Porous Silicon. Journal of The Electrochemical Society. 166(2):B9-B12. https://doi.org/10.1149/2.0051902jes ; S ; B9 ; B12 ; 166 ; 2 ; Canham, L. T. (1990). Silicon quantum wire array fabrication by electrochemical and chemical dissolution of wafers. Applied Physics Letters, 57(10), 1046-1048. doi:10.1063/1.103561 ; Dhanekar, S., & Jain, S. (2013). Porous silicon biosensor: Current status. Biosensors and Bioelectronics, 41, 54-64. doi:10.1016/j.bios.2012.09.045 ; Pacholski, C. (2013). Photonic Crystal Sensors Based on Porous Silicon. Sensors, 13(4), 4694-4713. doi:10.3390/s130404694 ; Hutter, T., Horesh, M., & Ruschin, S. (2011). Method for increasing reliability in gas detection based on indicator gradient in a sensor array. Sensors and Actuators B: Chemical, 152(1), 29-36. doi:10.1016/j.snb.2010.09.058 ; Mariani, S., ...

[EN] Periodic photonic configurations as photonic crystals (PhCs) and subwavelength grating (SWG) waveguides are gaining a renewed interest for the development of biosensing structures. By performing a proper design, these periodic configurations allow a significant sensitivity increase while keeping a compact footprint, what is achieved by exploiting concepts such as the slow-wave effect, the increase of the light-matter overlap or the interference of dispersion engineered modes. ; These results were achieved thanks to the funding received from the European Union (ICT-644242-SAPHELY, PHC634013-PHOCNOSIS and the operational program of the European Regional Development Fund (FEDER) of the Valencia Regional Government 2014¿2020), the Spanish Government (TEC2015-63838-C3-1-R-OPTONANOSENS and PID2019-106965RB-C21-PHOLOW), the Generalitat Valenciana (AVANTI/2019/123, ACIF/2019/009 and PPC/2020/037), the Universitat Politècnica de València (PAID-01-17, PAID-01-18 and OCUSENSOR). ; García-Rupérez, J.; Torrijos-Morán, L.; Gómez-Gómez, MI.; Martinez-Perez, P.; Ponce-Alcántara, S. (2021). High performance photonic biosensors based on periodic configurations. SPIE. 1-6. https://doi.org/10.1117/12.2576401 ; S ; 1 ; 6

[EN] Thrombin generation is a complex and finely regulated pathway that provokes dynamical changes of thrombin concentration in blood when a vascular injury occurs. In order to characterize the initiation phase of such process, when thrombin concentration is in the nM range, a label-free optical aptasensor is proposed here. This aptasensor combines a 1D photonic crystal structure consisting of a silicon corrugated waveguide with thrombin binding aptamers on its surface as bioreceptors. As a result, this aptasensor has been demonstrated to specifically detect thrombin concentrations ranging from 270 pM to 27 nM with an estimated detection limit of 33.5 pM and a response time of ~2 min. Furthermore, it has also been demonstrated that this aptasensor is able to continuously respond to consecutive increasing concentrations of thrombin and to detect binding events as they occur. All these features make this aptasensor a good candidate to continuously study how thrombin concentration progressively increases during the initiation phase of the coagulation cascade. ; This research was supported by a co-financed action by the European Union through the operational program of the European Regional Development Fund (FEDER) of the Valencian Community 2014-2020, the Generalitat Valenciana through the PROMETEO project AVANTI/2019/123 and by Universitat Politecnica de Valencia through grants PAID-01-17 and the project OCUSENSOR. ; Martinez-Perez, P.; Gómez-Gómez, MI.; Ivanova-Angelova, T.; Griol Barres, A.; Hurtado Montañés, J.; Bellieres, LC.; García-Rupérez, J. (2020). Continuous Detection of Increasing Concentrations of Thrombin Employing a Label-Free Photonic Crystal Aptasensor. Micromachines. 11(5):1-12. https://doi.org/10.3390/mi11050464 ; S ; 1 ; 12 ; 11 ; 5 ; CRAWLEY, J. T. B., ZANARDELLI, S., CHION, C. K. N. K., & LANE, D. A. (2007). The central role of thrombin in hemostasis. Journal of Thrombosis and Haemostasis, 5, 95-101. doi:10.1111/j.1538-7836.2007.02500.x ; Mann, K. G., Brummel, K., & Butenas, S. (2003). ...

© 2020 Optical Society of America]. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibited. ; [EN] An aptasensor based on periodic 1D corrugated waveguides is demonstrated to be suitable for the specific and continuous detection of thrombin at nM concentrations in real time with an estimated detection limit of 33.5 pM. ; This research was supported by a co-financed action by the European Union through the operational program of the European Regional Development Fund (FEDER) of the Valencian Community 2014-2020, the Generalitat Valenciana through the PROMETEO project AVANTI/2019/123 and the grant ACIF/2019/009, and by Universitat Politècnica de València through grants PAID-01-17 and the project OCUSENSOR. ; Martinez-Perez, P.; Gómez-Gómez, MI.; Torrijos-Morán, L.; Ivanova-Angelova, T.; Griol Barres, A.; Hurtado Montañés, J.; Bellieres, LC. (2020). 1D Periodic Corrugated Waveguides for Real-Time Detection of Increasing Concentrations of Thrombin. OSA (Optical Society). 1-2. https://doi.org/10.1364/iprsn.2020.ITu4A ; S ; 1 ; 2