1. Rapid Detection and Identification of Overdose Drugs in
Saliva by Surface-Enhanced Raman Spectroscopy
Chetan Shende, Frank E. Inscore, Atanu Sengupta,
Hermes Huang and Stuart Farquharson
Screening Abused Drugs in Saliva
at Road-Side & Emergency-Room
for Driver Impairment & Overdose
Funding:
UK Road Policing Technologies
Home Office Scientific Development
Branch
NIH and NSF
www.rta.biz
Pittcon 2012
RTA Booth #2110
chetan@rta.biz Providing Chemical Information When & Where You Need It

2. Challenge: Drugs in saliva
National Highway Traffic Safety Administration Stats:
2007: 11% of drivers stopped tested positive for drugs
2009: 18% of driver fatalities tested positive for drugs
The analyzer must typically provide the following:
• Specificity – Identify and discriminate drugs (No False Positives!)
• Sensitivity – Detect ~10-8 M or less (10-50 ppb)
• Reproducibility – Accurate and Repeatable (No False Negatives!)
• Speed – Analysis within 10 minutes
• Field Usable – Battery Operated
and Rugged

3. The Solution: SERS
Specificity: Every chemical produces a unique Raman spectrum
allowing unequivocal identification.
Sensitivity: Silver and gold nanoparticles increase Raman signals by
1 million times or more allowing 10-8M (ppb) detection.
Raman:
Pure Cocaine
CH3 + H Cl -
N
CO2CH3
SERS: O2 C
100 ppb Cocaine Cocaine Hydrochloride

4. Gold Sol-Gel SERS Capillary
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5. RTA’s SERSID - Trace Chemical Analyzer
2010
Patents: 6623977, 6943031, 6943032, 7312088,
7393691, 7393692, 7462492, 7462493, 7713914

6. UK Road-Side Screening: Required Drugs
35 drugs & metabolites were measured
31 active on gold, 4 (barbiturates) active on silver
Spectra search worked for all drugs Providing Chemical Information When & Where You Need It

7. The Proposed Device
The proposed SERS-RSSD-DD (Road Side Screening Device for Drug
Detection) will extract, identify, and quantify the presence of drugs (and
metabolites) in driver saliva at ~10-8M within 8-10 minutes.
6
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8. SERS of Representative Illicit, Prescription & OTC
Drugs in Expanded Gold Spectral Library (150)
PCP Diazepam
Methamphetamine Ritalin
MDMA Demerol
LSD Hydrocodone
Heroin Oxycodone
Acetaminophen
Acetylsalicylic acid
Ibuprofen
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9. Library Search: Measure Priority Drugs
Spectra search and identification works for all drugs
Hit Quality Name
1 0.001 Nordiazepam
2 0.010 Methadone
3 0.010 Oxazepam
4 0.010 Temazepam
5 0.012 Norcodeine
Hit Quality Name
1 0.036 Nordiazepam
2 0.357 Temazepam
3 0.363 Diazepam
4 0.373 Methadone
5 0.392 Oxazepam
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10. Cocaine: Static Concentration Data
50 ppb Cocaine
Background from glass capillary
25 ppb = 7x10-8M It can be subtracted.
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11. Sensitivity: Static ROC Curves of Cocaine
50 ppb
100 ppb
25 ppb
75 ppb
50 ppb
25 ppb
0 ppb
• ROC = establish threshold that signal can be detected above noise.
• K value = statistically significant separation between true & false response.
• K > 3.29 used by US Army for 95% probability of detection.
• Sensitivity = 48 ppb. Indicates that Cocaine SERS peaks can be
positively detected above noise 95% of the time at 48 ppb and higher.
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12. Developed Saliva Extraction Method
1. Collect 0.5 ml in 1 min 2. Expel sample into buffer 3. Filter sample
4. Draw sample into microSPE 5. Elute cocaine from SPE 6. Inject sample in SERS Capillary
7. Measure spectrum Capillary microSPE used for extraction
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13. 50 ppb Drug in Saliva Samples
Extracted from 0.5 mL saliva & detected in 10-minutes!!
Cocaine 50ppb
Hit Quality Name
Diazepam 50ppb 1 0.236 Cocaine
1 0.171 Diazepam
PCP 50ppb
1 0.171 PCP
Methadone 50ppb 1 0.066 Methadone
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14. Cocaine Extracted from Saliva
Saliva ROC Curve: A) 75, B) 50, C) 25 ppb
Probability of detection is 66% at 25 ppb, 92 % at 50ppb and
100% at 75 ppb, at 95% confidence level.
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15. R&D: SERS Lab-On-Chip
Different Lab-on-Chip designs used
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16. Preliminary LOC Results: in Saliva at 50 ppb
diazepam 50ppb
amphetamine 50ppb
Library reference
cocaine 50ppb
PCP 50ppb
methadone 50ppb
All Drugs Correctly Identified by Spectral Match!
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17. Actual Saliva Measurements: UK Tests
In Water
Results:
50 ppb Cocaine
Spectra of samples measured
by UK personnel
1 ppm PCP
Note:
Cocaine, Methamphetamine, & PCP
spectra are very similar, but sufficiently
different to be identified.
In Saliva In Saliva
50 ppb PCP 100 ppb Cocaine
100 ppb Metham-
Male Saliva
phetamine
Female 50 ppb PCP
Saliva

18. Real Clinical Saliva Samples
Chronic user, male #1 Casual user, female
Sample collected 30 minutes
after use
male #2 5 hours after use
All Samples Correctly Identified by Spectral Match!
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19. 150 Drugs in
Expanded Gold
SERS Library:
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20. Summary: saliva drug analysis
• Non-Invasive: Cotton Swab
• Field Portable: 7 pound Raman analyzer
• Small Sample Volume: < 1 mL
• Rapid & Simple Analysis: 10 minutes (total)
• Specificity: similar drugs can be differentiated
• Generality: over 250 drugs measured
• Sensitivity: measured < 50 ppb in saliva
References:
1) Detection of Drugs of Abuse in Saliva by Surface-enhanced Raman
spectroscopy. Applied Spectroscopy, 65, 9 (2011).
2) Rapid Detection and Identification of Overdose Drugs in Saliva by Surface-
enhanced Raman Scattering Using Fused Gold Colloids. Pharmaceutics, 3,
425-439 (2011).
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