Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 Jan 8;187(2):104.
doi: 10.1007/s00604-019-4101-6.

Aptamer-based cocaine assay using a nanohybrid composed of ZnS/Ag2Se quantum dots, graphene oxide and gold nanoparticles as a fluorescent probe

Oluwasesan Adegoke  1 , Magda A Pereira-Barros  2 , Svetlana Zolotovskaya  3 , Amin Abdolvand  3 , Niamh Nic Daeid  2
Affiliations

Aptamer-based cocaine assay using a nanohybrid composed of ZnS/Ag2Se quantum dots, graphene oxide and gold nanoparticles as a fluorescent probe

Oluwasesan Adegoke et al. Mikrochim Acta. .

Abstract

Authors report on a new fluoro-graphene-plasmonic nanohybrid aptamer-based fluorescent nanoprobe for cocaine. To construct the nanoprobe, newly synthesized glutathione-capped ZnS/Ag2Se quantum dots (QDs) were first conjugated to graphene oxide (GO) to form a QD-GO nanocomposite. The binding interaction resulted in a fluorescence turn-ON. Thereafter, cetyltrimethylammonium bromide (CTAB)-gold nanoparticles (AuNPs) were directly adsorbed on the QD-GO nanocomposite to form a novel QD-GO-CTAB-AuNP nanohybrid assembly that resulted in a fluorescence turn-OFF. Streptavidin (strep) was then adsorbed on the QDs-GO-CTAB-AuNP nanohybrid assembly which allowed binding to a biotinylated MNS 4.1 anticocaine DNA aptamer (B) receptor. The addition of cocaine into the strep-B-QDs-GO-CTAB-AuNP aptamer nanoprobe system aided affinity to the aptamer receptor and in turn turned on the fluorescence of the nanoprobe in a concentration-dependent manner. Under optimum experimental conditions, we found the strep-B-QD-GO-CTAB-AuNP to be far superior in its sensitivity to cocaine than the tested strep-B-QDs (no GO and CTAB-AuNPs), strep-B-QD-CTAB-AuNP (no GO) and strep-B-QD-GO (no CTAB-AuNP). In addition, the investigation of localized surface plasmon resonance (LSPR) amplified signal from tested plasmonic NPs shows that CTAB-AuNPs was far superior in amplifying the fluorescence signal of the nanoprobe. A detection limit of 4.6 nM (1.56 ng.mL-1), rapid response time (~2 min) and excellent selectivity against other drugs, substances and cocaine metabolites was achieved. The strep-B-QD-GO-CTAB-AuNP aptamer-based fluorescent nanoprobe was successfully applied for the determination of cocaine in seized adulterated cocaine samples. Graphical abstractSchematic representation of the streptavidin-biotin-quantum dot-graphene oxide-cetyltrimethylammonium bromide-gold nanoparticle aptamer-based fluorescent nanoprobe for cocaine.

Keywords: Fluorescence; Gold nanoparticle; Graphene oxide; Nanohybrid; Quantum dots.

PubMed Disclaimer

Figures

Graphical abstract
Graphical abstract
Schematic representation of the streptavidin-biotin-quantum dot-graphene oxide-cetyltrimethylammonium bromide-gold nanoparticle aptamer-based fluorescent nanoprobe for cocaine.
Scheme 1
Scheme 1
Descriptive representation of the strep-B-QDs-GO-CTAB-AuNP aptamer-based fluorescence nanoprobe for cocaine. GO is first conjugated to the QDs to form a QDs-GO nanocomposite which then results in fluorescence emission enhancement (ON state). Plasmonic CTAB-AuNP is then adsorbed to the QDs-GO nanocomposite to form a QDs-GO-CTAB-AuNP nanohybrid assembly and the fluorescence emission is quenched (OFF state). Streptavidin protein is then adsorbed onto the QDs-GO-CTAB-AuNP nanohybrid assembly and a biotinylated DNA anticocaine aptamer receptor is bonded to the adsorbed streptavidin. Cocaine being added to the system, binds to the aptamer receptor and this interaction switches on the fluorescence intensity of the strep-B-QDs-GO-CTAB-AuNP nanohybrid assembly in a concentration-dependent manner
Fig. 1
Fig. 1
a SEM images of (a) GO, b QDs-GO nanocomposite and c QDs-GO-CTAB-AuNP nanohybrid
Fig. 2
Fig. 2
a TEM images of (a) GO, (b) GSH-ZnS/Ag2Se QDs, (c) CTAB-AuNPs, (d) QDs-GO nanocomposite and (e) QDs-GO-CTAB-AuNP nanohybrid
Fig. 3
Fig. 3
a UV/vis and PL emission spectra of GSH-ZnS/Ag2Se QDs. UV/vis absorption spectra of (b) GO and (c) CTAB-AuNPs. (d) Raman spectra of GO, QDs-GO nanocomposite and the QDs-GO-CTAB-AuNP nanohybrid. Λexc = 290 nm
Fig. 4
Fig. 4
a PL emission spectra of the QDs before conjugation, QDs-GO nanocomposite, QDs-GO-CTAB-AuNP and strep-B-QDs-GO-CTAB-AuNP nanohybrid assembly. b UV/vis absorption spectra of CTAB-AuNPs before binding, QDs-GO nanocomposite, QDs-CTAB-AuNPs, QDs-GO-CTAB-AuNP and the strep-B-QDs-GO-CTAB-AuNP nanohybrid assembly
Fig. 5
Fig. 5
Selectivity of the strep-B-QD-GO-CTAB-AuNP aptamer nanoprobe to cocaine in comparison to other drugs and cocaine metabolites. Concentration of cocaine and other tested drugs and substances = 100 μM. Control = strep-B-QDs-GO-CTAB-AuNP solution without cocaine. Error bars are standard deviation of 3 replicate analysis
Fig. 6
Fig. 6
a Fluorescence “turn ON” spectra of the strep-B-QDs-GO-CTAB-AuNP aptamer nanoprobe to cocaine quantitative determination, b Photoluminescence (PL) intensity calibration plot for cocaine quantitative determination, c PL intensity signal for the determination of 100, 75 and 50 μM pure cocaine standard in comparison to adulterated cocaine samples containing benzocaine and pregabalin. Error bars are standard deviation of 3 replicate analysis. Λexc = 290 nm. Maximum PL intensity signal taken at ~370 nm
See this image and copyright information in PMC

References

    1. Roncancio D, Yu H, Xu X, Wu S, Liu R, Debord J, Lou X, Xiao Y. A label-free aptamer-fluorophore assembly for rapid and specific detection of cocaine in biofluids. Anal Chem. 2014;86:11100–11106. doi: 10.1021/ac503360n. - DOI - PubMed
    1. Barroso M, Dias M, Vieira DN, Queiroz JA, Lopez-Rivadulla M. Development and validation of an analytical method for the simultaneous determination of cocaine and its main metabolite, benzoylecgonine, in human hair by gas chromatography/mass spectrometry. Rapid Commun Mass Spectrom. 2008;22:3320–3326. doi: 10.1002/rcm.3738. - DOI - PubMed
    1. Bozokalfa G, Akbulut H, Demir B, Guler E, Gumus ZP, Demirkol AO, Aldemir E, Yamada S, Endo T, Coskunol H, Timur S, Yagci Y. Polypeptide functional surface for the aptamer immobilization: electrochemical cocaine biosensing. Anal Chem. 2016;88:4161–4167. doi: 10.1021/acs.analchem.6b00760. - DOI - PubMed
    1. Ma D-L, Wang M, He B, Yang C, Wang W, Leung C-H. A luminescent cocaine detection platform using a split g-quadruplex-selective iridium (III) complex and a three-way DNA junction architecture. ACS Appl Mater Interfaces. 2015;7:19060–19067. doi: 10.1021/acsami.5b05861. - DOI - PubMed
    1. Jayasena SD. An emerging class of molecules that rival antibodies in diagnostics. Clin Chem. 1999;45:1628–1650. doi: 10.1093/clinchem/45.9.1628. - DOI - PubMed

Publication types

MeSH terms

LinkOut - more resources