Project Description
The transducer comprises arrays of monolithic silicon optocouplers specifically bio-functionalized and interfaced with integrated microfluidic channels. The optocouplers consist of silicon light emitting devices optically coupled to silicon nitride optical waveguides and silicon detectors. Such a biochip provides for the simultaneous optical detection of a number of biological analytes without the need of external optical components. The main project output is a monolithic silicon microphotonic biochip integrated with microfluidic channels and recognition biomolecules as well as the associated readout and control electronics assembled in a portable bioanalytical microsystem to be tested with specific panels of pituitary hormones, steroid hormones and DNA. The main milestones are the sensitive and wide dynamic range monolithic optical biosensing, affordable silicon multianalyte biochips, and portable readout and control electronics.
The monolithic optoelectronic transducer integrating LED's, waveguides and the detector.
Photograph of the chip showing the nine LED's (left) and the single detector (right). All the waveguides start from the LED's and converge to the single detector. Also, shown is the on chip microchannel meandering over the optocoupler waveguides.
More specifically, the optical microchip monolithically integrates on silicon extremely thin and narrow optical waveguides along with self-aligned light emitting diodes (LED) and photodetectors (silicon p/n junction). The LEDs are based on silicon avalanche diodes that emit light when biased beyond their breakdown point, while the waveguides are made of deposited silicon nitride. The optocoupler array is functionalized into an affinity sensor by properly modifying each optical fiber surface with a different recognition molecule or probe (proteins, hormones, DNA) that bind the analyte. Signal transduction occurs by sensing the analyte binding induced optical transmission losses in the LED-photodetector optical link. To enhance sensitivity metal nanoparticles and liposome vesicles are employed as labels due to their strong interaction with the evanescent field of the waveguided optical modes. Additionally, label free detection is made possible by micropatterning of the biomolecular probe on the fiber surface so that a latent photonic crystal is created which upon selective analyte binding develops the latent pattern on the fiber and induces optical filtering. Polymer microfluidic channels along the optical waveguides ensure proper interaction of reagents and the sample with the immobilized biomolecular probes. Finally, readout and control electronics will be built to test the performance of the device under real clinical conditions against a complete panel of hormones for diagnosis of female fertility disorders and a set of disease predisposing mutations of breast cancer 1 (BRCA1) gene.
- Monolithic Optoelectronic Transducer
- Transducer Packaging, Reusable and Disposable Cartridge, interfacing
- Readout Electronics and Instrumentation
- Bioanalytical Applications- Development of Biochips