TY - JOUR
T1 - Methylone screening with electropolymerized molecularly imprinted polymer on screen-printed electrodes
AU - Couto, Rosa A.S.
AU - Mounssef, Bassim
AU - Carvalho, Félix
AU - Rodrigues, Cecília M.P.
AU - Braga, Ataualpa A.C.
AU - Aldous, Leigh
AU - Gonçalves, Luís Moreira
AU - Quinaz, M. Beatriz
PY - 2020/8/1
Y1 - 2020/8/1
N2 - Methylone (also known as bk-MDMA) is a substituted cathinone developed to elicit similar psychotropic effects as 4-methylenedioxymethamphetamine (MDMA, also known as ecstasy). Although methylone is a scheduled substance, its specific structural features means it generally cannot be detected and quantified using the same conditions commonly employed for ecstasy. This work therefore describes the development of an electroanalytical method for the selective quantification of methylone. This method uses an electropolymerized molecularly imprinted polymer (MIP) on the surface of screen-printed gold electrodes (SPAuEs), using 2-mercaptobenzimidazole (2-MBI) as the building monomer and methylone as the analyte template. The construction and optimization of the SPAuE-MIP sensor was studied, step-by-step, using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Additionally, the direct electrooxidation of methylone was investigated, and methylone-MIP interactions probed computationally. Ultimately, square-wave voltammetry (SWV) quantification of methylone using the SPAuE-MIP sensor was demonstrated to be both sensitive and selective. The electroanalytical determination showed suitable analytical parameters as: intra-day repeatability of 1.5%, a limit of detection (LOD) of 1.1 μmol L−1 (0.23 mg L−1) and a linear range up to 50 μmol L−1 (ca. 10 mg dL−1) with an r2 of 0.996, as well as much higher currents towards the analyte than similar compounds and commonly present interferents.
AB - Methylone (also known as bk-MDMA) is a substituted cathinone developed to elicit similar psychotropic effects as 4-methylenedioxymethamphetamine (MDMA, also known as ecstasy). Although methylone is a scheduled substance, its specific structural features means it generally cannot be detected and quantified using the same conditions commonly employed for ecstasy. This work therefore describes the development of an electroanalytical method for the selective quantification of methylone. This method uses an electropolymerized molecularly imprinted polymer (MIP) on the surface of screen-printed gold electrodes (SPAuEs), using 2-mercaptobenzimidazole (2-MBI) as the building monomer and methylone as the analyte template. The construction and optimization of the SPAuE-MIP sensor was studied, step-by-step, using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Additionally, the direct electrooxidation of methylone was investigated, and methylone-MIP interactions probed computationally. Ultimately, square-wave voltammetry (SWV) quantification of methylone using the SPAuE-MIP sensor was demonstrated to be both sensitive and selective. The electroanalytical determination showed suitable analytical parameters as: intra-day repeatability of 1.5%, a limit of detection (LOD) of 1.1 μmol L−1 (0.23 mg L−1) and a linear range up to 50 μmol L−1 (ca. 10 mg dL−1) with an r2 of 0.996, as well as much higher currents towards the analyte than similar compounds and commonly present interferents.
KW - Bath salts
KW - Computational modelling
KW - Electroanalysis
KW - Molecular recognition
KW - Non-labelled sensing of recreational drugs
KW - Novel psychoactive substance (NPS)
UR - http://www.scopus.com/inward/record.url?scp=85085062090&partnerID=8YFLogxK
U2 - 10.1016/j.snb.2020.128133
DO - 10.1016/j.snb.2020.128133
M3 - Article
AN - SCOPUS:85085062090
SN - 0925-4005
VL - 316
JO - Sensors and Actuators, B: Chemical
JF - Sensors and Actuators, B: Chemical
M1 - 128133
ER -