Gadolinium Manganese Oxide Nanorod Catalyst via a Facile Hydrothermal Approach: Application for Voltammetric Sensing of Antibiotic Drug Rifampicin in Pharmaceutical and Biological Samples

Abstract

This study constructs a rough-surfaced rod structure of gadolinium manganese oxide fabricated by a glassy carbon electrode (GMO NRs/GCE). The resulting nanostructure was applied as an efficient electrocatalyst for the antibiotic drug rifampicin (RIF) sensor. Studies included a crystal structure by X-ray diffraction, a morphology study using field emission scanning electron microscopy, transmission electron microscopy, a functional group examination by Fourier transform infrared spectroscopy, and an elemental state study by X-ray photoelectron spectroscopy. As-synthesized samples were characterized systematically by electrochemical methods including cyclic voltammetry (CV), differential pulse voltammetry detection, and electrochemical impedance spectroscopy. The improving electrochemical behaviors of GMO NRs could be ascribed to the outstanding electrocatalytic activity with the high surface area and good conductivity. Under the experimental conditions, the quantitative measurement of RIF resulted in a large and wide linear range of 0.15 to 136.15 µM, a low detection limit was calculated to be 0.071 µM. The sensor had good selectivity, reproducibility, and high stability. Importantly, the GMO NRs sensor was effectively applied to determine RIF in serum, urine, and pharmaceutical samples with satisfactory accuracy and recovery.

State of the Art on Developments of (Bio)Sensors and Analytical Methods for Rifamycin Antibiotics Determination

“…The molecular structures of the various rifamycins differ by the type and the position of the substituents on the aromatic ring; the most common representatives of this antibiotic class are shown in Figure 1 [ 26 , 30 ]. These molecules have different functional groups (e.g., −OH in both the aliphatic bridge and on the aromatic rings, amine, amide, furanone, methoxy and acetyl) [ 31 ], thus being generated chiral centers that make the compounds optically active [ 26 ]. The presence of the hydroxyl groups confers them with antioxidant properties and makes them adequate for radicalic polymerization reactions [ 29 ].…”

“…Long-term or excess use of RIF may produce some adverse effects, the most important being hepatotoxicity, which causes liver damage leading, for example, to jaundice. Other side effects include fever [ 66 ], arthralgia [ 31 ], kidney failure [ 67 ], fatigue, dizziness, gastrointestinal disorders [ 68 ] generating nausea, vomiting, appetite loss, diarrhea, sore throat, headache, immunological [ 53 ] and allergic reactions [ 52 ]. Moreover, RIF causes orange coloration in urine, sweat and tears [ 28 ].…”

“…RIF and RSV ( Figure 1 ) are hydroquinone derivatives (−OH groups in positions 1 and 4, Figure 1 ) and possess a third phenolic −OH moiety (position 8), which can be chemically or electrochemically oxidized [ 40 ] at various solid bare electrodes (e.g., GCE [ 85 ], CPE [ 80 ] and the disposable PGE [ 84 ]) or modified sensors obtained at various substrates, such as GCE [ 28 , 29 , 32 , 37 , 45 , 52 , 65 , 66 , 67 , 68 , 85 , 90 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 121 ], SPE [ 36 , 53 , 115 ], CPE [ 21 , 26 , 80 , 88 , 116 , 117 ], ITO [ 118 ], Ag [ 55 ], Au [ 50 , 86 ] and Pt [ 119 , 120 ]. Most often, the electrodes were employed as sensing devices in voltammetric [ 26 , 27 , 28 , 31 , 36 , …”

“…The signal at more anodic potential was irreversible, while the others were reversible [ 28 , 53 ], quasi-reversible [ 36 , 52 , 82 , 112 , 116 ] or even irreversible [ 67 ]. The (quasi)reversible couple involved an exchange of two electrons and two protons, and was related to the hydroquinone-quinone system of the 1,4-dihydroxynaphtalene structure [ 26 , 27 , 28 , 31 , 36 , 52 , 53 , 65 , 82 , 110 , 116 ]. The signal situated at more anodic potential was assigned to the irreversible one electron/one proton oxidation of the piperazynil-imino moiety of RIF [ 26 , 27 , 28 , 53 , 110 ] or of the phenolic hydroxyl (position 8) [ 26 , 112 , 116 ].…”

“…In order to improve its selectivity and sensitivity, the sensor’s electroactive surface was chemically or electrochemically modified with one or more materials ( Table 1 ), leading to (1) an increased electroactive surface area [ 52 , 68 ] (e.g., the effective surface area of the DyNWs/CPE was approximately eight times larger than that of the bare CPE [ 116 ], that of the CoEnQ10/Fe 3 O 4 NPs/MWCNTs/GCE was about 3.3 fold as large as that of GCE [ 67 ] and bare GCE (0.068 cm 2 ) < MoSe 2 /GCE (0.102 cm 2 ) < rGO/β-CyD/GCE (0.138 cm 2 ) < MoSe 2 /rGO/β-CyD/GCE (0.214 cm 2 ) [ 37 ]) and (2) faster electron transfer by decreasing the charge transfer resistance [ 52 , 68 , 110 , 118 ] (e.g., GCE (368.94 Ω) > GMONRs/GCE (113.39 Ω) [ 31 ] or GCE (748.04 Ω) > MoSe 2 /GCE (354.58 Ω) > rGO/β-CyD/GCE (236.41 Ω) > MoSe 2 /rGO/β-CyD/GCE (105.02 Ω) [ 37 ]).…”