2 research outputs found
Nanoelectromechanical Infrared Spectroscopy with In Situ Separation by Thermal Desorption: NEMS-IR-TD
We present a novel method for the quantitative analysis
of mixtures
of semivolatile chemical compounds. For the first time, thermal desorption
is integrated directly with nanoelectromechanical infrared spectroscopy
(NEMS-IR-TD). In this new technique, an analyte mixture is deposited
via nebulization on the surface of a NEMS sensor and subsequently
desorbed using heating under vacuum. The desorption process is monitored in situ via infrared spectroscopy and thermogravimetric
analysis. The resulting spectro-temporal maps allow for selective
identification and analysis of the mixture. In addition, the corresponding
thermogravimetric data allow for analysis of the desorption dynamics
of the mixture components. As a demonstration, caffeine and theobromine
were selectively identified and quantified from a mixture with a detection
limit of less than 6 pg (about 30 fmol). With its exceptional sensitivity,
NEMS-IR-TD allows for the analysis of low abundance and complex analytes
with potential applications ranging from environmental sensing to
life sciences
Additional file 1: of Survey of programmatic experiences and challenges in delivery of hepatitis B and C testing in low- and middle-income countries
Questionnaire sheets for feasibility survey. (PDF 176 kb