title: Objective Method for Presumptive Field-Testing of Illicit Drug Possession Using Centrifugal Microdevices and Smartphone Analysis.
abstract: Current colorimetric presumptive identification of illicit drugs for determining illegal possession of controlled substances by law enforcement relies solely on the subjective interpretation of color change using drug- or class-specific reactions. Here, we describe the use of inexpensive polyester-toner, rotation-driven microfluidic devices with a smartphone as a potential alternative for current presumptive colorimetric field-testing of illicit drugs, allowing for an objective and user-friendly image analysis technique for detection. The centrifugal microfluidic platform accommodates simultaneous presumptive testing of material from a single input to multiple reaction chambers, enabling rapid screening. Hue and saturation image analysis parameters are used to define threshold values for the detection of cocaine and methamphetamine as proof-of-principle with 0.25 and 0.75 mg/mL limits of detection, respectively, with nonvolatile reagents stored on-board and smartphone for detection. Reported LODs are lower than those concentrations used in the field. Additionally, the developed objective detection method addresses the testing of drugs with various common cutting agents, including those known to produce false negative and positive results. We demonstrate the effectiveness of the method by successfully identifying the composition of 30 unknown samples.
authors.affiliation: Department of Chemistry, ∥Department of Computer Science, ⊥Department of Mechanical and Aerospace Engineering, and #Department of Pathology, University of Virginia , Charlottesville, Virginia 22904, United States.|Office of the Chief Scientist and §Forensic Exploitation Directorate, Defense Forensic Science Center , Forest Park, Georgia 30297, United States.
authors.forename: Shannon T
authors.initials: ST
authors.lastname: Krauss
authors.affiliation: Department of Chemistry, ∥Department of Computer Science, ⊥Department of Mechanical and Aerospace Engineering, and #Department of Pathology, University of Virginia , Charlottesville, Virginia 22904, United States.|Office of the Chief Scientist and §Forensic Exploitation Directorate, Defense Forensic Science Center , Forest Park, Georgia 30297, United States.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Remcho
authors.affiliation: Department of Chemistry, ∥Department of Computer Science, ⊥Department of Mechanical and Aerospace Engineering, and #Department of Pathology, University of Virginia , Charlottesville, Virginia 22904, United States.|Office of the Chief Scientist and §Forensic Exploitation Directorate, Defense Forensic Science Center , Forest Park, Georgia 30297, United States.
authors.forename: Shelby M
authors.initials: SM
authors.lastname: Lipes
authors.affiliation: Department of Chemistry, ∥Department of Computer Science, ⊥Department of Mechanical and Aerospace Engineering, and #Department of Pathology, University of Virginia , Charlottesville, Virginia 22904, United States.|Office of the Chief Scientist and §Forensic Exploitation Directorate, Defense Forensic Science Center , Forest Park, Georgia 30297, United States.
authors.forename: Roman
authors.initials: R
authors.lastname: Aranda
authors.affiliation: Department of Chemistry, ∥Department of Computer Science, ⊥Department of Mechanical and Aerospace Engineering, and #Department of Pathology, University of Virginia , Charlottesville, Virginia 22904, United States.|Office of the Chief Scientist and §Forensic Exploitation Directorate, Defense Forensic Science Center , Forest Park, Georgia 30297, United States.
authors.forename: Henry P
authors.initials: HP
authors.lastname: Maynard
authors.affiliation: Department of Chemistry, ∥Department of Computer Science, ⊥Department of Mechanical and Aerospace Engineering, and #Department of Pathology, University of Virginia , Charlottesville, Virginia 22904, United States.|Office of the Chief Scientist and §Forensic Exploitation Directorate, Defense Forensic Science Center , Forest Park, Georgia 30297, United States.
authors.forename: Nishant
authors.initials: N
authors.lastname: Shukla
authors.affiliation: Department of Chemistry, ∥Department of Computer Science, ⊥Department of Mechanical and Aerospace Engineering, and #Department of Pathology, University of Virginia , Charlottesville, Virginia 22904, United States.|Office of the Chief Scientist and §Forensic Exploitation Directorate, Defense Forensic Science Center , Forest Park, Georgia 30297, United States.
authors.forename: Jingyi
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Chemistry, ∥Department of Computer Science, ⊥Department of Mechanical and Aerospace Engineering, and #Department of Pathology, University of Virginia , Charlottesville, Virginia 22904, United States.|Office of the Chief Scientist and §Forensic Exploitation Directorate, Defense Forensic Science Center , Forest Park, Georgia 30297, United States.
authors.forename: Richard E
authors.initials: RE
authors.lastname: Tontarski
authors.affiliation: Department of Chemistry, ∥Department of Computer Science, ⊥Department of Mechanical and Aerospace Engineering, and #Department of Pathology, University of Virginia , Charlottesville, Virginia 22904, United States.|Office of the Chief Scientist and §Forensic Exploitation Directorate, Defense Forensic Science Center , Forest Park, Georgia 30297, United States.
authors.forename: James P
authors.initials: JP
authors.lastname: Landers
mesh_terms: D003124:Colorimetry / Q000295:instrumentation; D013287:Illicit Drugs / Q000032:analysis*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation; D000068997:Smartphone / Q000295:instrumentation; D015813:Substance Abuse Detection / Q000295:instrumentation
chemical_list: D013287:Illicit Drugs