ABSTRACT
This review summarizes achievements in electrochemistry-related research of steroid-based compounds in clinical, pharmaceutical, and environmental analysis. Special attention is paid to compounds possessing none or only isolated double bonds at the steroid core. Their direct redox activity is limited to far positive/negative potentials under variety of conditions and electrode materials and relies on the functional groups attached to the steroid skeleton, or as the case may be its double bond or moieties present at the side chain. The possibilities of electroanalytical methods in sterol characterization and analysis are demonstrated in a table with 31 references devoted to direct voltammetric and amperometric methods of oxidation of cholesterol, phytosterols, oxysterols, and related compounds at carbon-based and metal-based nanoparticles modified electrodes, and the reduction of bile acids and their conjugates at mercury-based electrodes, and modified glassy carbon electrodes. Furthermore, methods based on the indirect oxidation of cholesterol using bromine species as a mediator at platinum electrode and non-enzymatic cholesterol biosensors are reviewed. Their drawbacks and benefits are discussed with respect to the challenging task of identification and quantitation of these compounds in biological matrices, otherwise mostly performed using expensive mass spectrometric techniques preceded by a chromatographic separation step.
Abbreviations
AD | = | amperometric detection |
AdSV | = | adsorptive stripping voltammetry |
CCE | = | carbon ceramic electrode |
CMC | = | critical micellar concentration |
DPP | = | differential pulse polarography |
ELISA | = | enzyme-linked immunosorbent assay |
FID | = | flame ionization detector FUMI |
HDL | = | high density lipoprotein |
ID-MS | = | isotopic dilution mass spectrometry |
IR | = | infra-red |
IT | = | ion trap |
LDL | = | low density lipoprotein |
LDR | = | linear dynamic range |
LOD | = | limit of detection |
LOQ | = | limit of quantation |
LS | = | linear sweep |
MALDI | = | matrix-assisted laser desorption/ionization |
MS | = | mass spectroscopy |
MWCNT | = | multi-wall carbon nanotubes |
NADH | = | nicotinamide adenine dinucleotide |
NMR | = | nuclear magnetic resonantion |
PAD | = | pulse amperometric detection |
RP-HPLC | = | reversed phase HPLC |
SWAdSV | = | square wave adsorptive stripping voltammetry |
SWV | = | square wave voltammetry |
TOF | = | time of flight |
Funding
This research was carried out within the framework of Specific University Research (SVV 260440). The research was financially supported by the Czech Science Foundation (project P206/12/G151).