{"id":9479,"date":"2016-08-01T06:16:34","date_gmt":"2016-08-01T06:16:34","guid":{"rendered":"http:\/\/revoscience.com\/en\/?p=9479"},"modified":"2016-08-01T06:16:34","modified_gmt":"2016-08-01T06:16:34","slug":"selective-sensing-of-harmful-molecules-with-light","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/selective-sensing-of-harmful-molecules-with-light\/","title":{"rendered":"Selective sensing of harmful molecules with light"},"content":{"rendered":"

Scientists are developing more highly sensitive devices for the detection of biological and chemical compounds.<\/strong><\/em><\/p>\n

\n

\"\u00a92016<\/a>
\u00a92016 Muhammad Umar Khan and Brian Corbett.<\/figcaption><\/figure>\n

Surface plasmon resonance (SPR) devices are the benchmark in optical sensing. They are used for detecting biomarkers of disease, discovering drugs, analyzing chemicals, ensuring food quality and safety, and detecting pollutants in our environment. SPR devices can detect molecules within a few hundred nanometres of their metal surfaces. When a target molecule binds to sensing molecules placed on the device\u2019s surface, this alters the path of light travelling through the medium, changing its \u201crefractive index\u201d. This change of refractive index is used to indicate the molecule\u2019s presence.\u00a0<\/span><\/p>\n

In the figure at left, Sketch of a BSW-based sensor. A bio-recognition layer is attached to the surface to make the sensor selective. Only the desired analytes can attach to the recognition layer resulting in a change in refractive index (n) above the surface. The sensor surface can be separated into arrays of different bio-recognition analytes in order to obtain a multichannel response. [right] Calculated wavelength-dependent reflection in water (n=1.33) and IPA (n=1.37) environments. The inset shows the calculated electric field of fundamental TM mode using a 133 nm-thick silicon layer at an angle of 26.1\u00b0 with water as the overlying medium.\u00a0<\/span><\/p>\n

[pullquote]\u201cThe research shows that surface waves can be easily generated and they provide a sensitive measure to detect the binding of a material at a surface,\u201d says Corbett.[\/pullquote]<\/p>\n

Scientists are working on improving the sensitivity, compactness and cost of SPR devices by changing the materials used to make them.\u00a0<\/span>

Brian Corbett and Muhammad Khan of University College Cork in Ireland reviewed the latest research in the field of \u201cBloch surface wave\u201d devices, publishing their findings in the journal Science and Technology of Advanced Materials.<\/span>

Bloch surface waves (BSW) are light waves that travel on the surface of insulating \u2013 or \u201cdielectric\u201d \u2013 – alternatively layered materials, shown in the figure. Researchers are testing the use of dielectric materials, instead of the metals typically used for the surfaces of SPR devices, to develop BSW devices. By doing so, they are detecting even smaller changes in the material\u2019s refractive index.<\/span>

\u201cBloch surface waves can be used for a variety of sensing applications,\u201d says Corbett. \u201cThis research has taken place mainly in the last ten years with demonstrations in sensing vapours, various biomarkers, and protein aggregation, for example. They can also be potentially used as a platform for compact integrated optical circuits,\u201d he says. Corbett expects BSW devices to become commercially available in the coming few years.<\/span>

Corbett and Khan designed a simple BSW sensor, employing silicon as its surface material, which they believe has practical advantages due to the ease with which it delivers and detects light waves.<\/span>

\u201cThe research shows that surface waves can be easily generated and they provide a sensitive measure to detect the binding of a material at a surface,\u201d says Corbett. \u201cThe sensor surface is simple and easy to fabricate with sensitivities comparable and better than SPR sensors. These sensors can provide real-time sensing and may be a way to screen for the presence of biomarkers for different diseases, such as cancer and Alzheimer\u2019s disease, at the doctor\u2019s surgery.\u201d<\/span>

The sensors still need to be tested for their durability in real environments, says Corbett. The team\u2019s aim is to develop an on-chip sensing platform with high sensitivity that can ultimately be used in bench top or even smartphone-based devices, he says, with potential application in water quality monitoring.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Scientists are working on improving the sensitivity, compactness and cost of SPR devices by changing the materials used to make them.<\/p>\n","protected":false},"author":6,"featured_media":9480,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17],"tags":[],"class_list":["post-9479","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767.jpg",579,214,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767-150x150.jpg",150,150,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767-300x110.jpg",300,110,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767.jpg",579,214,false],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767.jpg",579,214,false],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767.jpg",579,214,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767.jpg",579,214,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767.jpg",579,214,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767.jpg",579,214,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767.jpg",579,214,false],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767.jpg",579,214,false],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767.jpg",579,214,false],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767.jpg",550,203,false],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767.jpg",95,35,false],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767.jpg",579,214,false],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767.jpg",96,35,false],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2016\/08\/3767.jpg",150,55,false]},"author_info":{"info":["Amrita Tuladhar"]},"category_info":"Research<\/a>","tag_info":"Research","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/9479","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=9479"}],"version-history":[{"count":0,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/9479\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/9480"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=9479"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=9479"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=9479"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}