Analytical development of a binuclear oxo-manganese complex bio-inspired on oxidase enzyme for doping control analysis of acetazolamide

Abstract

A bio-inspired electrochemical sensor using a binuclear oxo-manganese complex was evaluated and applied in the detection of a substance associated with doping in sports: acetazolamide (ACTZ). Investigation was made of the influence of different experimental variables on the electrocatalytic oxidation of ACTZ by the bio-inspired sensor, such as pH and interfering species. The bio-inspired sensor showed the best response in the range from 5.00×10(-9) to 7.00×10(-8) mol L(-1) ACTZ, with a linear range from 5.00×10(-9) to 2.50×10(-8) mol L(-1) and a detection limit of 4.76×10(-9) mol L(-1). The sensor exhibited characteristics similar to the Michaelis-Menten model of an enzymatic electrode, due to the use of a multinucleated complex of manganese with μ-oxo units, which was able to mimic the properties of enzymes with manganese as a cofactor in their composition, such as Mn-containing oxidase. The determination of ACTZ with the bio-inspired sensor was evaluated using three different synthetic biological fluids (plasma, saliva, and urine), demonstrating its viability for use with real samples. The analysis of ACTZ in real urine samples using the bio-inspired sensor, simulating the method adopted by the World Anti-Doping Agency, which revealed viable, suggesting a new and promising platform to be used in these analysis.

Saliva, a Magic Biofluid Available for Multilevel Assessment and a Mirror of General Health—A Systematic Review

“…Machini et al developed an electrochemical sensor based on a binuclear oxo-manganese complex for the detection of acetazolamide, a drug associated with doping in sports. The sensor testing in saliva samples revealed a detection limit of 4.76 × 10 −9 mol·L −1 and maximum recovery errors of +2%, similar to the ones obtained in blood plasma and urine [60].…”

Improved Electrical Wiring of Glucose Oxidase Enzyme with an in-Situ Immobilized Mn(1,10-Phenanthroline)2Cl2-Complex/Multiwalled Carbon Nanotube-Modified Electrode Displaying Superior Performance to Os-Complex for High-Current Sensitivity Bioelectrocatalytic and Biofuel Cell Applications

“…mol wt = 451.14) were noticed confirming the existence of Mn III −μ-O oxo −Mn III type of complex on the f-MWCNT@Mn(Phen) 2 Cl system. Furthermore, based on the standard electrode potentials (E°) of the Mn redox states, 43 plausible redox reactions noticed with the f-MWCNT@Mn(Phen) 2 Cl are depicted as a Mn III −O− Mn III /Mn IV −O−Mn IV redox state (E°′ = 0.489 V vs Ag/ AgCl). 44 Overall, it is proposed that under electrified conditions at GCE/f-MWCNT surface, the Mn(phen) 2 Cl 2 complex gets converted to a [Mn 2 III (Phen) 4 (O)(Cl) 2 ] 2+ like intermediate, which has been further trapped by anionic (sulfonic acid of Nafion), π−π (graphitic structure), hydrogen bonding sites (carboxylic functional group of f-MWCNT) of the electrode (Scheme 1).…”

Non-Invasive Electrochemical Biosensors Operating in Human Physiological Fluids

“…Additional to that, the detection of bacteria, viruses, and whole cells is possible, like Helicobacter pylori, Streptococcus sanguinis, Escherichia coli, Staphylococcus aureus, Chikungunya viruses [113][114][115][116][117][118] or different antibodies [48,66,114,119], e.g., HIV [48,66,120]. On the top, different drugs [49,51,80,121], like alcohol [53,66] and cocaine [66,122], as well as neurotransmitters [49,66,123] can be determined in saliva. The related diseases to the different biomolecules are cancer [51,70,[73][74][75][76][77]79,80,124], oral cancer [56,67,72,108,109], breast cancer [56,67], diabetes [49,60,67,85], and different cardiovascular diseases [68,…”