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- All Subjects: Biosensors
- All Subjects: obstacle avoidance
- Creators: Harrington Bioengineering Program
Nanoscale confinement biogenetic silica template-based electrical biosensor assay offers the user the ability to detect and quantify the biomolecules. Diatoms have been demonstrated as part of a sensor. The sensor works on the principle of electrochemical impedance spectroscopy. When specific protein biomarkers from a test sample bind to corresponding antibodies conjugated to the surface of the gold surface at the base of each nanowell, a perturbation of electrical double layer occurs resulting in a change in the impedance.
Diatoms are also a new source of inspiration for the design and fabrication of nanostructured materials. Template-directed deposition within cylindrical nanopores of a porous membrane represents an attractive and reproducible approach for preparing metal nanopatterns or nanorods of a variety of aspect ratios. The nanopatterns fabricated from diatom have the potential of the metal-enhanced fluorescence to detect dye-conjugated molecules.
Another approach presents a platform integrating biogenic silica nanostructures with micromachined silicon substrates in a micro
ano hybrid device. In this study, one can take advantages of the unique properties of a marine diatom that exhibits nanopores on the order of 40 nm in diameter and a hierarchical structure. This device can be used to several applications, such as nano particles separation and detection. This platform is also a good substrate to study cell growth that one can observe the reaction of cell growing on the nanostructure of frustule.
To achieve a sensing diameter of 1-2 nanometers, the diatom shells were used as substrates to perform ion-channel reconstitution experiments. The immobilized diatom shell was functionalized using silane chemistry and lipid bilayer membranes were formed. Functionalization of the diatom shell surface improves bilayer formation probability from 1 out of 10 to 10 out of 10 as monitored by impedance spectroscopy. Self-insertion of outer membrane protein OmpF of E.Coli into the lipid membranes could be confirmed using single channel recordings, indicating that nano-BLMs had formed which allow for fully functional porin activity. The results indicate that biogenic silica nanoporous substrates can be simulated using a simplified two dimensional geometry to predict the current when a nanoparticle translocates through a single aperture. With their tiered three-dimensional structure, diatom shells can be used in to form nano-lipid bilayer membranes and can be used in ion-channel reconstitution experiments similar to synthetic nanoporous membranes.
Falls are known to be a common occurrence and a costly one as well, as they are the second leading cause of unintentional deaths and millions of other injuries worldwide. Falls often occur due to an increase in trunk flexion angle, so this experiment aims to reduce the trunk flexion received while stepping over an obstacle. To achieve this a soft actuator was attached to the trunk and pressure was sent as subjects walked and stepped over an obstacle presented on a treadmill. The pressure is meant to stiffen the back which should in theory reduce the trunk flexion angle and lower the chances of falling. In this experiment, two groups were tested: three participants from a control group (healthy young adults) and three participants from an experimental group (healthy elderly adults). Since elderly adults have the highest fall risk due to overall lack of stability, they are the experimental group and the focus for this experiment. The results from the study showed that elderly adults had a beneficial effect with the soft actuator as there was a noticeable difference in trunk flexion when the device was attached. The experiment also supported prior research that stated that trunk flexion was greater in elderly adults than younger adults. Despite the positive results, further studies should be done to prove that the soft devices influence lowering trunk flexion angle as well as to see if the device has any noticeable effect on younger adults.