[1] Photonics Engineering Group, University of Cantabria, Santander
[2] New Technologies and Chemistry Faculty, Military University of Technology, Warsaw
[3] Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi (CNR-IMM), Rome
[4] CIBER-bbn, Instituto de Salud Carlos III, Madrid
[5] Department of Electronic Technology, Carlos III University, Madrid
[6] Instituto de Investigación Sanitaria Valdecilla (IDIVAL), Santander