Optical sensing in microfluidic lab-on-a-chip by femtosecond-laser-written waveguides.
We use direct femtosecond laser writing to integrate optical waveguides into a commercial fused silica capillary electrophoresis chip. High-quality waveguides crossing the microfluidic channels are fabricated and used to optically address, with high spatial selectivity, their content. Fluorescence from the optically excited volume is efficiently collected at a 90 degree angle by a high numerical aperture fiber, resulting in a highly compact and portable device. To test the platform we performed electrophoresis and detection of a 23-mer oligonucleotide plug. Our approach is quite powerful because it allows the integration of photonic functionalities, by simple post-processing, into commercial LOCs fabricated with standard techniques.
Martinez Vazquez
Rebeca
R
Istituto di Fotonica e Nanotecnologie-CNR, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133, Milan, Italy.
Osellame
Roberto
R
Cretich
Marina
M
Chiari
Marcella
M
Dongre
Chaitanya
C
Hoekstra
Hugo J W M
HJ
Pollnau
Markus
M
van den Vlekkert
Hans
H
Ramponi
Roberta
R
Cerullo
Giulio
G
D005453:Fluorescence; D044085:Microfluidics / Q000295:instrumentation*; D055095:Optics and Photonics