During the past decade, the ability of surface-enhanced Raman spectroscopy (SERS) to measure extremely low concentrations, such as mg/L and below, and the availability of hand-held Raman spectrometers, has led to a significant growth in the number and variety of applications of SERS to real-world problems. Most of these applications involve the measurement of drugs, such as quantifying medication in patients, identifying illicit drugs in impaired drivers, and more recently, identifying drugs used as weapons. Similar to Raman spectroscopy, most of the point-of-care and field applications involve the identification of the drug to determine the course of action. However, unlike Raman spectroscopy, spectral libraries are not readily available to perform the necessary identification. In a large part, this is due to the uniqueness of the commercially available SERS substrates, each of which can produce different spectra for the same drug. In an effort to overcome this limitation, we have measured numerous drugs using the most common, and readily available SERS material and hand-held Raman analyzers, specifically gold colloids and analyzers using 785 nm laser excitation. Here we present the spectra of some 39 drugs of current interest, such as buprenorphine, delta-9 tetrahydrocannabinol, and fentanyl, which we hope will aid in the development of current and future SERS drug analysis applications.

A rudimentary flow strip, based on SERS, was developed and used to measure drugs, such as fentanyl, in saliva, plasma, and blood. Fully developed, the strip could be used with hand-held Raman spectrometers as a simple, point-of-care drug analyzer.

A bench top instrument has been constructed which allows for the measurements of radiance, directional-hemispherical reflection, and directional-hemispherical transmission from materials at elevated temperatures from 100 to over 2000 °C. The instrument measures these radiative properties over a wide spectral range, in the near- and mid-IR, from 12 500 to 500 cm−1 (0.8–20 μm). These measurements are then processed to determine the spectral emittance of the material and the temperature at the point of measurement. The instrument has applications for (1) industrial quality control of radiative properties of processed materials; (2) research and development of new materials; (3) temperature measurement by optical techniques in the near- and mid-IR; and (4) determination of heat transfer properties of materials. This article describes the instrument and its novel components, and presents measurement results for several materials.

Pharmaceutical drugs are available to astronauts to help them overcome the deleterious effects of weightlessness, sickness and injuries. Unfortunately, recent studies have shown that some of the drugs currently used may degrade more rapidly in space, losing their potency before their expiration dates. To complicate matters, the degradation products of some drugs can be toxic. Here, we present a preliminary investigation of the ability of Raman spectroscopy to quantify mixtures of four drugs; acetaminophen, azithromycin, epinephrine, and lidocaine, with their primary degradation products. The Raman spectra for the mixtures were replicated by adding the pure spectra of the drug and its degradant to determine the relative percent contributions using classical least squares. This multivariate approach allowed determining concentrations in ~10 min with a limit of detection of ~4% of the degradant. These results suggest that a Raman analyzer could be used to assess drug potency, nondestructively, at the time of use to ensure crewmember safety.