Optical biosensors, by using metallic nano structures, is one of the common type of biosensor. The optical biosensors, which are Localized Surface Plasmon Resonance (LSPR), allow the sensitive and selective detection of wide range of analyses including viruses, toxins, drugs, antibodies, tumour biomarkers and tumour cells. One important parts of optical biosensor is the miniature elements made of novel materials, such as Gold (Au) and SIlver (Ag). Conventional methods, such as Photolithography, Focus Ion Beam, Chemical Etching, are used to fabricate the metallic nano structures. Disadvantage of these conventional methods are high fabrication costs and high stringency in the chemical processes.
This technology proposed new manufacturing process involve stamping process with non-hazardous chemical as well as Argon gas sputtering deposition process to fabricate metallic nanostructures on substrate for chemical sensing application. This method is low in fabrication cost and is without the stringency chemical in the process. Therefore, this new fabrication technology is suitable to transfer into industry scale manufacturing for bio-sensing application, where company can utilize this low cost and cleaner technology, instead of conventional processes, which is highly hazardous.
Technology Features, Specifications and Advantages
Metallic nanodot arrays smaller than the wavelength of light causes collective oscillation of electrons in a metal dot due to the electromagnetic field of light, that is, Localized Surface Plasmon Resonance (LSPR), and a peak appears at the resonant wavelength on an absorption spectrum. Since this peak wavelength is affected by molecules adhered on the nanodots, application to chemical sensors utilizing this peak wavelength variation have been studied. Aggregate of this kind of metallic structures are expected to behave as a new optical material, which has specially designed optical properties that have never been seen in nature.
This manufacturing process aim to develop an efficient fabrication process of metallic nano structures of the same size as the wavelength of visible light, such as a metallic nanodot arrays. In this process, a plastic mold is made by hot stamp method from a mother mold, and the plastic mold is used to “chemical stamp” onto substrates. The plastic mold are very low cost and reusable. Then, a metal thin film is deposited on the stamped substrate by Argon gas spattering deposition. Finally, the nanodot arrays are appeared on the substrate for chemical sensing application.
Most important advantages of this technology are:
1. high throughput,
2. low cost, and
3. without hazardous chemical in the process.
Therefore, this new fabrication process is ready to transfer to the bio sensing company.
This technology present the possible advanced manufacturing method to fabricate the gold (Au) nanostructured on glass substrate as the LSPR optical bio-chemical sensors application. This methods use the polymer film for stamping the chemical on the substrate and directly coating on the top of the chemical patterned substrate. It is confirmed that, this process can fabricate metallic nanostructures with very high throughput. Therefore, this method can be utilized in the nanofabrication laboratory in the bio-sensing company to produce the plasmonic biosensors with the reduction in the fabrication costs and non-dangerous chemical in the process.
For the application of metallic nanostructures on substrate, the example of the LSPR spectroscopy as the cancer cell therapy as the studied of gold nanoparticles on several types of cancer cells. Based on the optimal conditions of particle absorption at different wavelengths in the visible spectrum are estimated. Therefore, the Au nanoparticles and optical spectra of this Au nanoparticles configuration can be utilized to specified type of cancer cell therapies. (From Reference Paper 3). It was confirmed that the metallic nanostructures on substrate can be utilized as the bio-sensor application.
For the customers who need to license this new nanofabrication methods to using in the laboratory of company may gain the advantages as:
• Low fabrication cost of nanofabrication; because of this method used the low cost of polymer film as PET, COP to utilize as the polymer mold.
• Low stringency chemical of nanofabrication; This methods using chemicals doesn't have to be dangerous, such as Acetone, so long as you take basic steps to set up your work area to avoid problems.
• Very high throughput, For the comparison in the same size of fabrication area, the new method in this study can fabricate in the large area, therefore this method can reduce the fabrication time for more than 50% of the conventional methods as Focus Ion Beam.
For the confirmation experiments in the laboratory scale for more than 3 years, the New Nanofabrication Methods by Chemical Printing and Argon Spatter Coating Process to Fabricate Metallic Nano Structures on Substrate for Bio-Chemical Sensor Application are ready to transfer to the industrial scale.