Staff directory

Publications

2017

  • A label-free nanostructured plasmonic biosensor based on Blu-ray discs with integrated microfluidics for sensitive biodetection

    López-Muñoz G.A., Estevez M.-C., Peláez-Gutierrez E.C., Homs-Corbera A., García-Hernandez M.C., Imbaud J.I., Lechuga L.M. Biosensors and Bioelectronics; 96: 260 - 267. 2017. 10.1016/j.bios.2017.05.020.

    Nanostructure-based plasmonic biosensors have quickly positioned themselves as interesting candidates for the design of portable optical biosensor platforms considering the potential benefits they can offer in integration, miniaturization, multiplexing, and real-time label-free detection. We have developed a simple integrated nanoplasmonic sensor taking advantage of the periodic nanostructured array of commercial Blu-ray discs. Sensors with two gold film thicknesses (50 and 100 nm) were fabricated and optically characterized by varying the oblique-angle of the incident light in optical reflectance measurements. Contrary to the use normal light incidence previously reported with other optical discs, we observed an enhancement in sensitivity and a narrowing of the resonant linewidths as the light incidence angle was increased, which could be related to the generation of Fano resonant modes. The new sensors achieve a figure of merit (FOM) up to 35 RIU−1 and a competitive bulk limit of detection (LOD) of 6.3×10−6 RIU. These values significantly improve previously reported results obtained with normal light incidence reflectance measurements using similar structures. The sensor has been combined with versatile, simple, ease to-fabricate microfluidics. The integrated chip is only 1 cm2 (including a PDMS flow cell with a 50 µm height microfluidic channel fabricated with double-sided adhesive tape) and all the optical components are mounted on a 10 cm×10 cm portable prototype, illustrating its facile miniaturization, integration and potential portability. Finally, to assess the label-free biosensing capability of the new sensor, we have evaluated the presence of specific antibodies against the GTF2b protein, a tumor-associate antigen (TAA) related to colorectal cancer. We have achieved a LOD in the pM order and have assessed the feasibility of directly measuring biological samples such as human serum. © 2017 Elsevier B.V.


2016

  • Multiple biomarkers biosensor with just-in-time functionalization: Application to prostate cancer detection

    Parra-Cabrera C., Samitier J., Homs-Corbera A. Biosensors and Bioelectronics; 77: 1192 - 1200. 2016. 10.1016/j.bios.2015.10.064. IF: 7.476

    We present a novel lab-on-a-chip (LOC) device for the simultaneous detection of multiple biomarkers using simple voltage measurements. The biosensor functionalization is performed in-situ, immediately before its use, facilitating reagents storage and massive devices fabrication. Sensitivity, limit of detection (LOD) and limit of quantification (LOQ) are tunable depending on the in-chip flown sample volumes. As a proof-of-concept, the system has been tested and adjusted to quantify two proteins found in blood that are susceptible to be used combined, as a screening tool, to diagnose prostate cancer (PCa): prostate-specific antigen (PSA) and spondin-2 (SPON2). This combination of biomarkers has been reported to be more specific for PCa diagnostics than the currently accepted but rather controversial PSA indicator. The range of detection for PSA and SPON2 could be adjusted to the clinically relevant range of 1 to 10. ng/ml. The system was tested for specificity to the evaluated biomarkers. This multiplex system can be modified and adapted to detect a larger quantity of biomarkers, or different ones, of relevance to other specific diseases. © 2015 Elsevier B.V.