Rapid and robust detection methods for poison and microbial contamination.
Real-time on-site monitoring of analytes is currently in high demand for food contamination, water, medicines, and ingestible household products that were never tested appropriately. Here we introduce chemical methods for the rapid quantification of a wide range of chemical and microbial contaminations using a simple instrument. Within the testing procedure, we used a multichannel, multisample, UV-vis spectrophotometer/fluorometer that employs two frequencies of light simultaneously to interrogate the sample. We present new enzyme- and dye-based methods to detect (di)ethylene glycol in consumables above 0.1 wt % without interference and alcohols above 1 ppb. Using DNA intercalating dyes, we can detect a range of pathogens ( E. coli , Salmonella , V. Cholera, and a model for Malaria) in water, foods, and blood without background signal. We achieved universal scaling independent of pathogen size above 10(4) CFU/mL by taking advantage of the simultaneous measurement at multiple wavelengths. We can detect contaminants directly, without separation, purification, concentration, or incubation. Our chemistry is stable to ± 1% for >3 weeks without refrigeration, and measurements require <5 min.
Department of Mechanical Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, USA. hoehl@mit.edu
Melanie M
MM
Hoehl
Peter J
PJ
Lu
Peter A
PA
Sims
Alexander H
AH
Slocum
D000818:Animals; D001419:Bacteria / Q000737:chemistry / Q000302:isolation & purification; D001774:Blood Chemical Analysis / Q000379:methods*; D002417:Cattle; D005470:Fluorometry / Q000295:instrumentation / Q000379:methods*; D005504:Food Analysis / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D011042:Poisons / Q000032:analysis*; D013053:Spectrophotometry / Q000295:instrumentation / Q000379:methods*; D014867:Water / Q000032:analysis; D014871:Water Microbiology
D011042:Poisons; D014867:Water