TY - JOUR
T1 - Optical biosensor based on hollow integrated waveguides
AU - Cadarso, Víctor J.
AU - Fernández-Sánchez, César
AU - Llobera, Andreu
AU - Darder, Margarita
AU - Domínguez, Carlos
PY - 2008/5/1
Y1 - 2008/5/1
N2 - The first absorbance biosensor based on pure silicon hollow integrated waveguides is presented in this work. With the use of horseradish peroxidase (HRP) as a model recognition element, an enzymatic sensor for the measurement of hydrogen peroxide was fabricated, numerically simulated, and experimentally characterized. Waveguides with widths ranging from 50 to 80 μm, having a depth of 50 μm and lengths up to 5 mm were easily fabricated by just one photolithographic step. These were further modified by covalent immobilization of HRP using silanization chemistry. Simulation studies of the proposed approach showed a sensor linear behavior up to 300 μM H2O2 and a sensitivity of 2.7 × 10-3 AU/μM. Experimental results were in good agreement with the simulated ones. A linear behavior between 10 and 300 μM H2O2, a sensitivity of 3 × 10-3 AU/μM, and a signal-to-noise ratio around 20 dB were attained. Also, kinetic studies of the activity of the immobilized enzyme on the silicon waveguide surface gave an apparent Michaelis-Menten constant of 0.44 mM. The simple technology proposed in this work enables the fabrication of cost-effective, easy-to-use, miniaturized biosensor generic platforms, these being envisioned as excellent candidates for the development of lab-on-a-chip systems.
AB - The first absorbance biosensor based on pure silicon hollow integrated waveguides is presented in this work. With the use of horseradish peroxidase (HRP) as a model recognition element, an enzymatic sensor for the measurement of hydrogen peroxide was fabricated, numerically simulated, and experimentally characterized. Waveguides with widths ranging from 50 to 80 μm, having a depth of 50 μm and lengths up to 5 mm were easily fabricated by just one photolithographic step. These were further modified by covalent immobilization of HRP using silanization chemistry. Simulation studies of the proposed approach showed a sensor linear behavior up to 300 μM H2O2 and a sensitivity of 2.7 × 10-3 AU/μM. Experimental results were in good agreement with the simulated ones. A linear behavior between 10 and 300 μM H2O2, a sensitivity of 3 × 10-3 AU/μM, and a signal-to-noise ratio around 20 dB were attained. Also, kinetic studies of the activity of the immobilized enzyme on the silicon waveguide surface gave an apparent Michaelis-Menten constant of 0.44 mM. The simple technology proposed in this work enables the fabrication of cost-effective, easy-to-use, miniaturized biosensor generic platforms, these being envisioned as excellent candidates for the development of lab-on-a-chip systems.
UR - http://www.scopus.com/inward/record.url?scp=42949140371&partnerID=8YFLogxK
U2 - 10.1021/ac702293r
DO - 10.1021/ac702293r
M3 - Article
C2 - 18393473
AN - SCOPUS:42949140371
VL - 80
SP - 3498
EP - 3501
JO - Analytical Chemistry
JF - Analytical Chemistry
SN - 0003-2700
IS - 9
ER -