Eas 2011 Fei Invited Sers Talk Drugs In Saliva

Rapid Detection and Identification of Drugs in Saliva by
Surface-Enhanced Raman Spectroscopy
Frank E. Inscore, Chetan Shende, Atanu Sengupta,
Hermes Huang and Stuart Farquharson
Focus: SERS Applications in Biofluids
Screening Abused Drugs in Saliva
at Road-Side & Emergency-Room
for Driver Impairment & Overdose
Relevant R&D Funding to RTA:
NIH CN: 1R43CA94457-01
NSF CN: DMI-0215819
NASA CN: NNC05CA09C

Jet Propulsion Laboratories
(Dr. Eric Wong)

UK Road Policing Technologies
Home Office Scientific Development Branch
(Dr. Helen Turner, Dr. Audrey Carmichael)

www.rta.biz
860-635-9800 EAS 2011
inscore@rta.biz Providing Chemical Information When & Where You Need It RTA Booth #106

The Need & Challenge: Drugs in saliva
Analysis of chemo-drugs and metabolites for dosage control
• Dosage critical (to little noneffective, to much kills patient)
• Current analysis requires large sample volume (10-20 ml blood and/or urine)
• Traditional lab methods are labor intensive and time consuming
• Viable alternative is saliva, parent drugs/metabolites adequately represented (but at lower levels)
• Advantages of saliva, non-invasive (no needles) & 100X less potential interferents (99.5% water)

Road-side screening for determining drug induced driver impairment
National Highway Traffic Safety Administration Stats:
• 2007: 11% of drivers stopped tested positive for drugs
• 2009: 18% of driver fatalities tested positive for drugs

Emergency room assessment of overdose and drug abuse
U.S. Drug-Related Emergency Room (ER) Stats:
• 2004: 2.4 million visits
• 2009: 4.6 million visits
2.1 million attributed to illicit drugs
Cocaine, Heroin, Methamphetamine, PCP, MDMA, LSD, Methadone
2.3 million attributed to prescription & some to over-the-counter (OTC) drugs
Oxycodone, Diazepam & Acetaminophen

Providing Chemical Information When & Where You Need It

Challenge: Drugs in saliva
Critical need to rapidly identify offending drug(s), so that impaired drivers can be
arrested or appropriate medical care can be administered.

The analyzer must typically provide the following criteria:
• Specificity – Identify and Discriminate Drugs (with No False Positives!)
• Sensitivity – Detect ~10-8 M or less (e.g. 30 ppb cocaine is threshold)
• Reproducibility – Accurate and Repeatable (with No False Negatives!)
• Speed – Rapid Response and Analysis within 8-10 minutes
• Field Usable – Battery Operated and Rugged

In an effort to meet this need we have been investigating the ability of surface-
enhanced Raman spectroscopy (SERS) to detect and identify numerous drugs of
abuse in saliva at ng/mL concentrations within 10 minutes.

We present successful measurement of representative illicit, prescribed, and
over-the-counter drugs in saliva by SERS, with a focus on cocaine.


The Solution: SERS
Specificity: all chemicals (drugs/metabolites) produce a unique Raman spectrum
allowing unequivocal identification (no false-positives).
Sensitivity: Ag and Au nanoparticle substrates used to generate SERS amplify
Raman signals (increase scattering efficiency) by 1 million times or more
allowing required detection of 10-8 M (ppb) (no false-negatives).
CH3 + H Cl -
N
CO2 CH3
Raman: O2 C
Pure Cocaine Cocaine Hydrochloride

Au

Gold SERS: Ag
1 ppm Cocaine


How it works: Raman

Light Chemical
virt
H H Transmitted
hνo
H H hνvib
Absorbed (IR) hνo hνscat
H H
Raman
Raman
Scattered
hνscat vib1
Rayleigh hνvib
vib0

Laser light directed at a chemical generates Raman light.


Surface-enhanced Raman Spectroscopy

Raman, although weak effect, provides
molecular specificity hν
Ag
BUT, when a molecule is within
a laser induced plasmon field, H

H
N

N
H N

N
H

SERS
N

H

the efficiency of Raman scattering can Plasmon Field provides
increase by 106 i.e. 1 million times! Surface-Enhanced Single Molecule Detection
Raman Photon
Sub part-per million detection possible some argue this requires
enhancement factor (EF)
ALSO, chemical contribution of
can provide additional 103 enhancement 1012 -1014
Sub part-per-billion detection becomes
possible with SERS

SERS-Active Media
Traditional:
• Electrochemically Roughened Electrodes
• Metal Colloidal Hydrosols
• Metal Islands or Nanoparticles on Solid Supports
• Metal Coated Surface Structures
• Self-Assembled Monolayers (SAMs)

Recent:
• Metal-Doped Porous Media
• Periodic Apertures in Metals
• Metal Shells
• Fiber Optic Tips


Commercial SERS Substrates: Benzenethiol
benzenethiol Conc. EF (A)
LOW SENSITIVITY
SLOW RESPONSE
10-3M 102 BUT
REPRODUCIBLE

(B)
LESS REPRODUCIBLE
10-5M 10 4 SLOW RESPONSE
BUT
MODERATE SENSITIVITY

(C)
HIGH SENSITIVITY
AND
FAST RESPONSE
10-8M 107
(~10ppb)
AND
OK REPRODUCIBLE

RTA: LMC ~10-11M (0.01 ng/mL or 10 ppt) Providing Chemical Information When & Where You Need It

Approach: RTA SERS Patented Sampling Systems
provide instant response in seconds as opposed to 30-min or more!

2001: Simple SERS Sample Vials
Molecules Sol-Gel Matrix
Raman
in Solution
Scattering

Laser

Adsorbed
Molecules Metal Particle
silver gold

2003: SERS Microplate 2004: SERS-Active Capillary

1 10

High Throughput Screening Extraction and Pre-Concentration
U.S. Patents for RTA
6,623,977; 6,943,031; 6,943,032; 7,312,088; 7,393,691; 7,393,692; 7,462,492; and 7,462,493

2007: Functionalized Sol-Gel SERS Capillary
(affords greater selectivity and sensitivity)
PC

Std chromatographic media
OTC


R&D: SERS Lab-On-Chip
Different wafer, glass and plastic Lab-on-Chip designs used


RTA’s SERSID - Trace Chemical Analyzer’s
for Field and Lab Use
2010 2011

Patents: 6623977, 6943031, 6943032, 7312088,
7393691, 7393692, 7462492, 7462493, 7713914


The Proposal: The Device
The proposed SERS-RSSD-DD (Road Side Screening Device for Drug Detection) and SERS-ERSD-DD
(Emergency Room Screening Device for Drug Detection) will extract, identify, and quantify the presence
of drugs (and metabolites) in driver or patient saliva at ~10-8M within 8-10 minutes.

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

150 Drugs in
Expanded Gold
SERS Library:
Applicable to the ER
See recent RTA paper
Pharmaceutics 2011, 3, 425-439
doi:10.3390/pharmaceutics3030425


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


Library Search: Measure Priority Drugs
Spectra search and identification worked 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


Spectral Match Results for Mixtures
500ppm
nordiazepam /diazepam

Diazepam Ref

Nordiazepam Ref

500ppm
cocaine/diazepam

Diazepam Ref

Cocaine Ref

Cocaine: Static Concentration Data

50 ppb Cocaine

Background = Luminescence
25 ppb = 7x10-8M from glass capillary
It can be subtracted.


Sensitivity: Static ROC Curves of Cocaine
50 ppb
100 ppb

25 ppb
75 ppb

50 ppb

25 ppb

0 ppb

Conc. # of Mean Std Mean Std Log C at LMC at
substrates peak hgt Deviation Deviation (α) Conc. C K value K=3.29 95 %
Blank 10 0.002 0.0014 0.004 25 ppb 2.263 confidence
25 ppb 9 0.0113 0.006 50 ppb 3.343
50 ppb 10 0.0157 0.003 -7.31583 48 ppb

New Modified Gold Sol-Gel
ROC Curves 95% Confidence = 48 ppb
(10 capillaries measured at 9 spots per concentration)

Improve sub-ppb Detection via Pre-concentration
flowed 5 mL of Sensitivity and Reproducibility
25 ppb cocaine in water
achieved with flowing less than 5 mL of 25 ppb (10-8M)
cocaineHCl in HPLC water on new gold SG4(3H);
A detected at 95% confidence (K > 3.29) in under 5-min!

B
Also
static 25 ppb detected 25 ppb cocaineHCl on gold SG4 after extracted
cocaine in water from 1 mL HPLC water with SPE capillary column 8-min;
intensity 40x the static signal and is equivalent to a 1ppm
signal as observed on the static concentration curve.

extracted 5 mL of 25 ppb (7.3x10-8M) cocaineHCl
25 ppb cocaine in water

12.5 ppb (9.2x10-8M) amphetamine

static 25 ppb 25 ppb (8.7x10-8M) diazepam
cocaine in water


Develop 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


Cocaine Extracted from Saliva
25ppb cocaine in 0.5mL saliva extracted & detected in 8-min (from start to finish)

25 ppb Cocaine Amphetamine
in 0.5 ml Saliva
Diazepam

Methadone

PCP
25 ppb Cocaine
in 0.5 ml Water
500 750 1000 1250 1500 1750
Wavenumbers (cm-1)

Above drugs at 1ppm
extracted from 0.5 mL saliva in 8-min


Spectral Search and Match Results for Drugs in Saliva

50 ppb cocaine
100ppm Oxycodone
1ppm PCP

Lib. Oxycodone
1ppm diazepam

10ppm acetaminophen Lib. Hydrocodone

Unknown Oxycodone Cocaine PCP Diazepam Acetaminophen
(0.1 mg/mL water) (50 ng/mL) (1 mcg/mL) (1 mcg/mL) (10 mcg/mL)
Rank HQI Chemical HQI Chemical HQI Chemical HQI Chemical HQI Chemical

1 0.073 Oxycodone 0.287 Cocaine 0.019 PCP 0.022 Diazepam 0.276 Acetaminophen

2 0.734 Hydrocodone 0.348 Ethyl- benzoyl-ecgonine 0.315 Fentanyl 0.317 Temazepam 0.639 Sulfadoxine

3 0.800 Trazadone 0.349 Benzoyl-ecgonine 0.325 EMDP 0.328 Nor-diazepam 0.704 Serotonin


Further Test: 50ppb Drug in Saliva Samples

Cocaine 50ppb Hit Quality Name
1 0.236 Cocaine
Diazepam 50ppb
1 0.171 Diazepam

PCP 50ppb 1 0.171 PCP

Methadone 50ppb 1 0.066 Methadone


Drug in Saliva Extraction: Potential Interferents
50ppb in saliva via SPE method

Caffeine

Quinine
vitC
Mannitol

50ppb equal mixture
cocaine and caffeine
extracted from 0.5mL
saliva in 8-min 30ppb cocaine and
50ppb mannitol mixture
extracted from 0.5mL
saliva in 8-min

blank saliva extracted as
control

Correctly Identified Cocaine by Spectral Match!

Preliminary LOC Designs

Plastic Cover

SPE

PMMA with
Ag/Au
Channels

Glass Plate


Preliminary LOC Results: in Saliva at 50 ppb
amphetamine 50ppb
diazepam 50ppb

cocaine 50ppb

PCP 50ppb

methadone 50ppb

All Drugs Correctly Identified by Spectral Match!


Next Generation LOC Design

Buffered 3mL syringe
saliva sample
Lab-on-chip SPE capillary SERS capillary
0.2µm filter

Elution solvent Valve
reservoir Valve

Valve
Solvent waste
reservoir

Vacuum Sample waste reservoir


Summary
Critical need to rapidly identify offending drug(s) in impaired drivers and overdose in ER.

Demonstrated ability of surface-enhanced Raman spectroscopy (SERS) to detect and identify
numerous drugs in saliva at ng/mL concentrations within 8 minutes.

Identification is provided by matching measured spectra to a SERS library comprised of
over 150 different drugs, each of which possess a unique spectrum.

Trace detection is provided by gold nanoparticles trapped within a porous glass matrix that
generate SERS.

Speed is provided by a syringe driven sample system that extracts the drugs from saliva
AND provides SERS-activity.

Spectral collection is provided by a portable Raman analyzer.


Eas 2011 Fei Invited Sers Talk Drugs In Saliva

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