Alma Dudia

Biofunctionalized Lipid-Polymer Hybrid Nanocontainers with Controlled Permeability

We have successfully developed, for the first time, a novel polymer-lipid hybrid nanocontainer with controlled permeability functionality. The nanocontainer is made by nanofabricating holes with desired dimensions in an impermeable polymer scaffold by focused ion beam drilling and sealing them with lipid bilayers containing remote-controlled pore-forming channel proteins. This system allows exchange of solutions only after channel activation at will to form temporary pores in the container. Potential applications are foreseen in bionanosensors, nanoreactors, nanomedicine, and triggered delivery.

Analysis of phase error and cross talk for a multimode interference based multichannel biosensor

In this paper we present the novel compact structure of a multimode interference (MMI) based biosensor. We analyze its working principle, evaluate its expected measurement errors and discuss some possible techniques to reduce them. A full description of phase-error (PE) and cross-talk (CT) for the MMI based biosensor is done. Through simulations we have analyzed the windowing technique and the effect of CCD camera resolution in the reduction of PE and CT. We show that the windowing technique is very effective in reducing PE and CT, where the best results are achieved for the Blackman window with an average improvement coefficient of 1210. The reduction of spectral leakage from this window, due to the high roll-off rate of its side lobs, is dominant against the worse spectral resolution that this window has compared to the others. Increasing the CCD camera resolution from 6 × 103 pixels/m to 18 × 103 pixels/m is associated by a rapid reduction of PE and CT with an average improvement coefficient of 44.4. A further increase in the camera resolution is not necessary as it would increase the cost of the device with a very low profit in measurement accuracy.

Simulation of the novel compact structure of an interferometric biosensor based on multimode interference waveguides

We propose the novel structure of an interferometric biosensor based on multimode interference (MMI) waveguides. We present the design of the biosensor using eigenmode expansion (EME) method in accordance with the requirements and standards of todays photonic technology. The MMI structures with a 90 nm Si3N4 core are used as power splitters with 5 outputs. The 5 high-resolution images at the end of the multimode region show high power balance. We analyze the coupling efficiency of the laser source with the structure, the excess loss and power imbalance for different compact MMI waveguides with widths ranging from 45 μm to 15 μm. For a laser source with a tolerance of ±1mm in linearization we could achieve a coupling efficiency of 52%. MMI waveguides with tapered channels show excess loss values under 0.5 dB and power imbalance values under 0.08 dB. In addition, we show that for a 10 nm deviation of the source wavelength from its optimal value and for a 10 μm deviation of the MMI length from its optimal value, the performance of the MMI waveguides remains acceptable. Finally, we analyze the power budget of the whole biosensor structure and show that it is sufficient for the proper operation of this device.