title: Capacitive sensing of N-formylamphetamine based on immobilized molecular imprinted polymers.
abstract: A highly sensitive, capacitive biosensor was developed to monitor trace amounts of an amphetamine precursor in aqueous samples. The sensing element is a gold electrode with molecular imprinted polymers (MIPs) immobilized on its surface. A continuous-flow system with timed injections was used to simulate flowing waterways, such as sewers, springs, rivers, etc., ensuring wide applicability of the developed product. MIPs, implemented as a recognition element due to their stability under harsh environmental conditions, were synthesized using thermo- and UV-initiated polymerization techniques. The obtained particles were compared against commercially available MIPs according to specificity and selectivity metrics; commercial MIPs were characterized by quite broad cross-reactivity to other structurally related amphetamine-type stimulants. After the best batch of MIPs was chosen, different strategies for immobilizing them on the gold electrode's surface were evaluated, and their stability was also verified. The complete, developed system was validated through analysis of spiked samples. The limit of detection (LOD) for N-formyl amphetamine was determined to be 10μM in this capacitive biosensor system. The obtained results indicate future possible applications of this MIPs-based capacitive biosensor for environmental and forensic analysis. To the best of our knowledge there are no existing MIPs-based sensors toward amphetamine-type stimulants (ATS).
authors.affiliation: Faculty of Pharmaceutical Sciences, Department of Bioanalysis, Laboratory of Food Analysis, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.
authors.forename: Kinga
authors.initials: K
authors.lastname: Graniczkowska
authors.affiliation: Bundeskriminalamt, Forensic Science Institute, KT45 - Toxicology, 65173 Wiesbaden, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Pütz
authors.affiliation: Bundeskriminalamt, Forensic Science Institute, KT45 - Toxicology, 65173 Wiesbaden, Germany.
authors.forename: Frank M
authors.initials: FM
authors.lastname: Hauser
authors.affiliation: Faculty of Pharmaceutical Sciences, Department of Bioanalysis, Laboratory of Food Analysis, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium.
authors.forename: Sarah
authors.initials: S
authors.lastname: De Saeger
authors.affiliation: Faculty of Pharmaceutical Sciences, Department of Bioanalysis, Laboratory of Food Analysis, Ghent University, Ottergemsesteenweg 460, 9000 Ghent, Belgium. Electronic address: Natalia.Beloglazova@UGent.be.
authors.forename: Natalia V
authors.initials: NV
authors.lastname: Beloglazova
mesh_terms: D000662:Amphetamines / Q000032:analysis*; D000697:Central Nervous System Stimulants / Q000032:analysis*; D025802:Electric Capacitance; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D057230:Limit of Detection; D054802:Molecular Imprinting / Q000379:methods*; D058105:Polymerization; D011108:Polymers / Q000737:chemistry*; D014867:Water / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000662:Amphetamines; D000697:Central Nervous System Stimulants; D011108:Polymers; D014874:Water Pollutants, Chemical; D014867:Water; C024544:formetamide
keywords: Capacitive biosensor; Molecular imprinted polymers; N-formyl amphetamine; Water analysis