Periodic Reporting for period 4 - FLUINEMS (Suspended Fluidic nanochannels as optomechanical sensors for single molecules)
Berichtszeitraum: 2022-06-01 bis 2024-04-30
Detection of biomarkers is a key step for disease detection. For diagnosis at an early stage, usually their concentration is very low, and the needed detection methods need to be extremely sensitive, down to the single molecule level. In addition, these biomarkers come in complex media, like serum, and are mixed with other biomarkers, what makes the detection and analysis even more challenging.
In this project, we aim at the development of a device and associated read out methods for single molecule (e.g. protein or DNA) detection, identification and quantification. The device should be able to detect a variety of molecules, even when they are mixed. The objectives are the development of a nanodevice and its associated technology and cleanroom fabrication processes, the development and improvement of a sensitive enough read out method (optical, electrical, or a combination of both) and the proof of concept for the detection of molecules one by one.
In this project, we aim at the development of a device and associated read out methods for single molecule (e.g. protein or DNA) detection, identification and quantification. The device should be able to detect a variety of molecules, even when they are mixed. The objectives are the development of a nanodevice and its associated technology and cleanroom fabrication processes, the development and improvement of a sensitive enough read out method (optical, electrical, or a combination of both) and the proof of concept for the detection of molecules one by one.
We have developed nanofluidic devices capable of manipulating and confining liquid and molecules at the nanoscale. In these nanodevices, we have demonstrated the proof of concept for the detection and read out of the barcode of single molecules of DNA. These devices also work for the detection of DNA in complex biological media, like saliva or plasma.
These devices can be integrated with a variety of functional fluidic systems, where the liquids can be mixed, separated, or bioentities of different nature and size separated (e.g. bacteria or cells can be separated from small biomolecules like DNA or proteins).
These devices have also been integrated with ultra-sensitive read out capabilities. For example, the optical read out of the genomic barcode of DNA single molecules was shown, and the idea was further explored within the associated ERC PoC BIoREAD.
We have also been able to make the nanochannels of the fluidic devices suspended. In this way, after removing the supporting material, the nanochannels are free to mechanically move and resonate. For making such nanochannels, we have developed a nanofabrication process capable of internally coating the walls of the micro and nanochannels of the devices. The proprietary method, gas phase deposition in flow-through mode, consists of flowing and alternating gas precursors to make the inorganig material layer building up conformally along the walls of the enclosed micro and nanofluidic channels. With this method, we were able to coat microchannels with 10 um x 10 um cross section, and 5 cm long, what represents an ultra-high aspect ratio of 5000. With this method we are also able to coat nanochannels and nanoslits. We coated nanochannels, 500 nm x 500 nm cross section, 50 um long. FIB cross sections show that they are hollow after the process.
We have also mechanicallly characterized these suspended nanochannels. They show resonance frequencies in the MHz regime (from 2 and up to 9 MHz, depending on the specific geometry of the nanochannel). And the resonance shows sensitivity to the environment, as a promising first step for their use as ultra-sensitive mass sensors.
These devices can be integrated with a variety of functional fluidic systems, where the liquids can be mixed, separated, or bioentities of different nature and size separated (e.g. bacteria or cells can be separated from small biomolecules like DNA or proteins).
These devices have also been integrated with ultra-sensitive read out capabilities. For example, the optical read out of the genomic barcode of DNA single molecules was shown, and the idea was further explored within the associated ERC PoC BIoREAD.
We have also been able to make the nanochannels of the fluidic devices suspended. In this way, after removing the supporting material, the nanochannels are free to mechanically move and resonate. For making such nanochannels, we have developed a nanofabrication process capable of internally coating the walls of the micro and nanochannels of the devices. The proprietary method, gas phase deposition in flow-through mode, consists of flowing and alternating gas precursors to make the inorganig material layer building up conformally along the walls of the enclosed micro and nanofluidic channels. With this method, we were able to coat microchannels with 10 um x 10 um cross section, and 5 cm long, what represents an ultra-high aspect ratio of 5000. With this method we are also able to coat nanochannels and nanoslits. We coated nanochannels, 500 nm x 500 nm cross section, 50 um long. FIB cross sections show that they are hollow after the process.
We have also mechanicallly characterized these suspended nanochannels. They show resonance frequencies in the MHz regime (from 2 and up to 9 MHz, depending on the specific geometry of the nanochannel). And the resonance shows sensitivity to the environment, as a promising first step for their use as ultra-sensitive mass sensors.
These devices will have improved sensitivity due to their dimensions in the nanoscale and their ultra-low intrinsic mass. Also, due to the novel fabrication method, it is possible to make them as integral parts of real lab on a chip systems, where it is possible to inject a complex biological liquid, and use the lab on a chip to extract and enrich the target biomolecule, like DNA.