Electrochemical, Photoelectrochemical, and Surface Plasmon Resonance Detection of Cocaine Using Supramolecular Aptamer Complexes and Metallic or Semiconductor Nanoparticles

Golub, Eyal; Pelossof, Gilad; Freeman, Ronit; Zhang, Hong; Willner, Itamar

doi:10.1021/ac901551q

Cited by 252 publications

(161 citation statements)

References 57 publications

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“…Freeman et al 35 and Golub et al 36 conducted QD-based optical sensing as well as electrochemical sensing of cocaine by employing a split cocaineÀaptamer and pyrene modification to create supramolecular complexes. They demonstrated detection limits of 1 μM for FRET-based sensing and 10 μM for the amperometric response of the system respectively.…”

Section: ' Introductionmentioning

confidence: 99%

Aptamer Functionalized Microcantilever Sensors for Cocaine Detection

et al. 2011

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A cocaine-specific aptamer was used as a receptor molecule in a microcantilever-based surface stress sensor for detection of cocaine molecules. An interferometric technique that relies on measuring differential displacement between two microcantilevers (a sensing/reference pair) was utilized to measure the cocaine/ aptamer binding induced surface stress changes. Sensing experiments were performed for different concentrations of cocaine from 25 to 500 μM in order to determine the sensor response as a function of cocaine concentration. In the lower concentration range from 25 to 100 μM, surface stress values increased proportionally to coverage of aptamer/cocaine complexes from 11 to 26 mN/m. However, as the cocaine concentration was increased beyond 100 μM, the surface stress values demonstrated a weaker dependence on the affinity complex surface coverage. On the basis of a sensitivity of 3 mN/m for the surface stress measurement, the lowest detectable threshold for the cocaine concentration is estimated to be 5 μM. Sensing cantilevers could be regenerated and reused because of reversible thermal denaturation of aptamer. DisciplinesBiochemistry, Biophysics, and Structural Biology | Biomechanical Engineering CommentsReprinted (adapted) with permission from Langmuir, 2011, 27 (23) has established a standard of cocaine metabolite cutoff levels of 150 ng/mL and 100 ng/mL for initial screening and confirmatory cutoff levels, respectively. Current methods of initial screening and identifying biological samples for drugs of abuse can match the new standard for detection and identification of cocaine metabolite. For instance, enzyme multiplied immunoassay technique (EMIT) 2À4 and enzyme-linked immunosorbent assay (ELISA) 5À7 are the two predominant enzyme-base immunoassays utilized for screening tests. In both techniques, detection of the controlled substance is based on optical absorbance resulting from enzymatic activity. Gas chromatography coupled with mass spectrometry (GC-MS) 8À10 and high-performance liquid chromatography (HPLC) 11À13 can achieve detection levels required for confirmatory identification of controlled substances. These techniques require extensive sample preparation, a long performance time, and/or specialized instrumentation to validate drug presence. The sample often must be sent to the lab, which results in a significant delay in identification. 12,14À22Aptamer-based biosensors (often called aptasensors) have been investigated as an alternative method to overcome these drawbacks. Sensitivity and detection times of conventional and aptamerbased techniques are compared in Figure 1.Aptamers are synthetic oligonucleotides that recognize and bind to their respective targets. They are selected and characterized by SELEX (systematic evolution of ligands by exponential enrichment) process and proposed as an alternative to antibodies and other biomimetic receptors. Aptamers are much smaller than their protein (antibody) counterparts, and unlike antibodies, ligand binding is often accompanied by...

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Section: ' Introductionmentioning

confidence: 99%

Aptamer Functionalized Microcantilever Sensors for Cocaine Detection

et al. 2011

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“…In the presence of cocaine, aggregation occurred and the SPR of Au-NPs shifts, producing a color change from red to blue. Willner et al (223) worked on the use of aptamers in order to create smart surfaces, which respond to a desired target analyte. For instance, a cocaine aptasensor was developed using two anti-cocaine aptamer subunits; one subunit was assembled on a gold support, acting as an electrode or an SPR-active surface, and the second aptamer subunit was labeled with Pt-NPs or Au-NPs.…”

Section: Metal Nanoparticles For Biomedical Applicationsmentioning

confidence: 99%

“…The detection limit for cocaine was at best 1 mM. A long response time, w30 min, and the need to control the ionic strength of the solution seemed to be the major hurdles for this sensor configuration (223). Visual detection of cocaine was performed using a DNA modified linear polyacrylamide polymer, which was crosslinked with a cocaine aptamer and loaded with Au-NPs.…”

Section: Metal Nanoparticles For Biomedical Applicationsmentioning

confidence: 99%

Properties and Customization of Sensor Materials for Biomedical Applications

Zuliani¹,

Curto²,

Matzeu³

et al. 2014

Comprehensive Materials Processing

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“…The detection limit of the sensor was 3 × 10 -7 mol L -1 at 3σ, which is superior to the value of 1 × 10 -5 mol L -1 reported by Golub, using an aptasensor labeled with Pt nanoparticles to detect cocaine. 32 …”

Section: Effect Of the Incubation Time Of Cocainementioning

confidence: 99%