Item Details

title

FLUORESCENT LABELING OF SYNTHETIC CATHINONES AND PROTEINS VIA SULFOTETRAFLUOROPHENYL-FUNCTIONALIZED SQUARYLIUM DYES FOR ANALYSIS BY CAPILLARY ELECTROPHORESIS

author

Roberts, Jennifer Buchanan

abstract

New psychoactive substances (NPS) are a class of unregulated drugs, including synthetic cathinones, that cause paranoia, confusion, violence, and suicidal thoughts which often evade law enforcement and drug-screening efforts. Typically marketed as bath salts, they are cheap, widely available mimics of controlled stimulants with no legal medical application. Their ever-growing number and increased use call for rapid, selective detection. Few synthetic cathinones are innately fluorescent, so this work posits the use of new 4-sulfo-2,3,5,6-tetrafluorophenyl ester (STP ester)-functionalized squarylium (SQ) dyes, synthesized by our collaborators in Japan, as probes for the amine-based drug targets. The advantages of squarylium dyes include ease of functionalization, high molar absorptivities, narrow absorption and emission bands, and enhanced emission intensities upon analyte binding. The two used here differ by a hydrogen or dodecyl group, respectively, at the site of their indole nitrogen. This study aims to determine and optimize the efficacy of separation parameters for quantitative determination of SQ-STP derivatized bath salts using a variety of capillary electrophoresis (CE) systems with laser-induced fluorescence (LIF) detection. Initially, we used two commercial probes, BODIPY FL STP and ATTO-TAG FQ, to derivatize bath salts, but labeling was incomplete with the former, and the latter showed nonlinear quenching, making quantitative determination impossible. However, ATTO-TAG FQ proved effective in derivatization of bovine serum albumin (BSA) and threonine with sodium dodecyl sulfate (SDS) added in the separation buffer. When we implemented the novel SQ fluorophores, CE trials showed the enhancement of bath salt signal after ionic liquid, cyclodextrin, and carbon dots were added, enabling semi-quantitative determination. SQ-STPa/b labeled synthetic cathinones in a mixture comigrated. Capillary transient isotachophoresis (ctITP) of a complex mixture of large mucus proteins—mucin, lysozyme, and lactoferrin—was performed with SQ-STPb and afforded partial resolution. These results will enable improved biological assays to identify synthetic cathinones and proteins.  

subject

capillary electrophoresis

functionalized squarylium dyes

laser induced fluorescence

synthetic cathinones

contributor

Colyer, Christa L (committee chair)

Calloway, Clifton P (committee member)

Dos Santos, Patricia C (committee member)

Geyer, Scott M (committee member)

Hinze, Willie L (committee member)

date

2021-06-03T08:36:06Z (accessioned)

2022-06-02T08:30:14Z (available)

2021 (issued)

degree

Chemistry (discipline)

embargo

2022-06-02 (terms)

identifier

http://hdl.handle.net/10339/98804 (uri)

language

en (iso)

publisher

Wake Forest University

type

Dissertation