-A A +A
Over the last few years, a large demand for very sensitive, highly specific, cost-effective, and rapid methods to detect the concentration of chemical or biological species has been identified in several fields such as clinical diagnostics, drug development, environmental monitoring, food quality control, security, and counterterrorism. In particular, in so-called optical biochips, the miniaturization, parallelization, and integration of optical sensing schemes and measurements of biochemical targets can be achieved [1]. In a lab-on-chip (LOC), all the microfluidics and the optical transducing elements are placed on the same substrate (see Figure 11.1 for a typical LOC architecture). LOC systems are characterized by small dimensions (which imply small sample volumes, in the picoliter–femtoliter range), low cost, short analysis time and, furthermore, they can successfully perform multiplexed analyses within point-of-care (POC) testing schemes.In this introductive paragraph, we will focus on the sensing element of a LOC; in particular, we will report a brief review on some of the most recently conceived nanostructured transducing elements and architectures that have been implemented in LOC systems. Multiplexed quantification of three well-characterized cancer biomarkers (the antigens CEA, CA125, and Her-2/Neu (C-erbB-2)) from saliva and serum has been performed, exploiting the fluorescence emitted by functionalized nanoparticle quantum dots (QDs) in a microporous agarose bead array [2]. The scheme of detection is shown in Figure 11.2. The agarose beads, loaded into an anisotropically etched silicon chip provided with the proper microfluidics …
Publication date: 
1 Jan 2009

Luca De Stefano, Edoardo De Tommaso, Emanuele Orabona, Ilaria Rea, Ivo Rendina

Biblio References: 
Volume: 24 Pages: 3622
Biosens. Bioelectron