We demonstrate label-free molecule detection by using an integrated biosensor based on a Si3N4/SiO2 slot-waveguide microring resonator. Bovine serum albumin (BSA) and anti-BSA molecular binding events on the sensor surface are monitored through the measurement of resonant wavelength shifts with varying biomolecule concentrations. The biosensor exhibited sensitivities of 1.8 and 3.2 nm/(ng/mm2) for the detection of anti-BSA and BSA, respectively. The estimated detection limits are 28 and 16 pg/mm2 for anti-BSA and BSA, respectively, limited by wavelength resolution.
© 2008 Optical Society of America
Original Manuscript: November 8, 2007
Revised Manuscript: February 26, 2008
Manuscript Accepted: February 26, 2008
Published: March 28, 2008
Vol. 3, Iss. 5 Virtual Journal for Biomedical Optics
Carlos A. Barrios, María José Bañuls, Victoria González-Pedro, Kristinn B. Gylfason, Benito Sánchez, Amadeu Griol, A. Maquieira, H. Sohlström, M. Holgado, and R. Casquel, "Label-free optical biosensing with slot-waveguides," Opt. Lett. 33, 708-710 (2008)