FEATURE PORTABLE SPECTROSCOPY
which the sample can then be compared with – or Raman techniques, like Raster Orbital Scanning (ROS). ROS is a sampling technique that moves the laser in a daisy-like pattern over the sample surface to probe a larger and more representative area. This is advantageous for measuring complex mixtures like pharmaceuticals – Ocean Optics has demonstrated its benchtop IDRaman reader, which has ROS technology, to test Alka-Seltzer, an over-the-counter antacid with multiple active ingredients. Then there are also authentication methods that use a fluorescent tag or other specific emissions incorporated into the drug. Certain tags have been approved by the FDA as consumable, so they can be integrated into the medicine and measured with a spectrometer. A combination of fluorescent tags can not only identify a particular product, but also which batch it is and other information. Most fluorescent tags are integrated into the packaging, according to Langston, but there is also an interest to incorporate them directly in the pill.
Drug detection on the go
The need for small, portable instruments for use in the field would help in the detection and prevention of counterfeit medicines, according to Langston: ‘Most fraud happens in the distribution
chain a long way from the factory and away from the labs, so it’s a lot easier to have an instrument in the field and actually doing random testing.’ ‘You can test a lot more samples a lot quicker, and you can also actually do it closer to where the customer is taking that medicine,’ he added. Another advantage of having smaller instruments when checking authenticity, Langston said, is that testing can be carried out more discreetly. ‘Often, the distributor that you might be inspecting, or the vendor, is not going to want to be told that the goods that they’re selling are counterfeit, or found out if they are aware of the crime,’ he said. ‘So, having something that is small and portable also makes it easier to [test] discreetly.’ Portable, low cost spectrometers could also aid in the detection of recreational drugs. A pressing challenge facing the police and import inspection facilities is the rise of new types of narcotics, or ‘designer drugs’, which are being created to cheat test systems used by authorities, explained Jason Pierce of Stellarnet: ‘[The drugs are sent] through typical mail delivery routes, and they are basically derivatives of MDMA – the manufacturers can just change the molecule slightly and make a completely new drug.’ In the United States, usually, police use colorimetric assays or sniffer dogs to detect illegal drugs, but these aren’t effective for identifying their derivatives, Pierce added. ‘A Raman spectrometer with a database containing these new types of synthetic derivatives could easily determine whether an imported drug is in fact... a type of designer drug.’ ‘I’ve worked with
Professors of forensic chemistry, and even some crime labs, and they want each of these different crime units to have a Raman spectroscopy system, even in every police car.’ Pierce said that this scenario is quite a way
The StellarCase-Raman from Stellarnet can be used in the field for drug analysis. It’s a research-grade instrument inside a portable case
device, which is being created by start-up company Diagnostic AnSERS, uses surface-enhanced Raman spectroscopy (SERS) to detect the amount of marijuana in a person’s blood. SERS requires two components: a Raman
Most fraud happens in the distribution chain a long way from the factory and away from the labs, so it’s a lot easier to have an instrument in the field and actually doing random testing
off, as it would take time to create a database of synthesised drug products. The Raman systems would also need to be miniaturised and the price point dropped to a few thousand dollars for Raman systems to ‘get into every officer’s hand’.
Start-up tech A project to develop a ‘marijuana breathalyser’ for police officers to test suspected impaired drivers by the roadside was awarded second place in the SPIE Startup Challenge, which took place during Photonics West in February in San Francisco. The
www.electrooptics.com | @electrooptics
spectrometer and a SERS substrate. Diagnostic AnSERS has developed a patent-pending inkjet process that reduces the cost of producing these substrates without sacrificing sensitivity. During the competition at Photonics West, the company’s co- founder Sean Vigile said that it was working with spectrometer companies to bring down the cost of the spectroscopy part of the instrument so that it can be used as a roadside test. Another start-up
company is developing a SWIR imaging spectrometer for checking whether pills such as Viagra are fake or not. Stratio, which was founded by Stanford engineers, has received $750,000 worth of funding from the US’ National
Science Foundation, and plans to start selling its device later this year for $199. San Jose-based Stratio’s product, called LinkSquare, is connected to a smartphone via USB. It shines light from the visible to the near-infrared onto a pill, and the way in which the light reflects back is captured by an image sensor and illustrated in two graphs on the smartphone’s display. In a demo of the device described in MIT Technology Review, the process is repeated with two other similar-looking pills, also purporting to be Viagra (one is a generic pill, the other a fake), and their graphs look noticeably different to the branded pill’s spectral signature. So far, Viagra is the only drug
MARCH 2016 l ELECTRO OPTICS 21
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Stellarnet
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