A recent advancement on nanomaterials for electrochemical sensing of sulfamethaoxole and its futuristic approach

Sulfamethoxazole (SMX) forms the high harmfulness and causing negative health impacts to well-being human and environment that found to be major drastic concern. It is subsequently important to keep in track for monitoring of SMX through convenient detecting devices which include the requirement of being minimal expense and potential for on location environmental applications. Nanomaterials based design has been proposed to determine the SMX antibiotic which in turn provides the solution for this issue. In spite of the critical advancement accomplished in research, further endeavors are yet to foster the progress on electrochemical sensors with the guide of various functional nanomaterials and guarantee the effective transportability for such sensors with improved coherence. Moreover, it has been noticed that, only few reports on electrochemical sensing of SMX detection using nanomaterials was observed. Hence an in-depth evaluation of electrochemical sensing systems using various nanomaterials for SMX detection was summarized in this review. Additionally this current review centers with brief presentation around SMX hazard evaluation followed by study on the current logical techniques to feature the importance for SMX detection. This review will provide the sum up view towards the future ideas of this field which assists in improving the detecting strategies for SMX detection.

Water-soluble manganese porphyrins as good catalysts for cipro- and levofloxacin degradation: Solvent effect, degradation products and DFT insights

Synthetic manganese porphyrins (MnPs), in the presence of oxidants, were employed for the degradation of fluoroquinolone antibiotics. Ciprofloxacin (CIP) and levofloxacin (LEV) degradation by iodosylbenzene, iodobenzene diacetate, H₂O₂ and meta-chloroperbenzoic acid using water-soluble MnP catalysts yielded thirteen and nine products, respectively, seven of which have been proposed for the first time. The MnP catalysts have demonstrated the ability to degrade these antibiotics to a high degree (up to 100% degradation). The structures of the degradation products were proposed based on mass spectrometry analysis, and density functional theory calculations could confirm how the substituent moieties attached to the basic chemical structure of the fluoroquinolones influence the degradation reactions. CIP has been shown to be a more reactive substrate towards the porphyrinic catalysts tested because of its three-membered ring. However, the catalysts could almost completely degrade LEV, highlighting the ability of these porphyrins to act as catalysts to degrade environmental pollutants.

Voltammetric Sensors Based on Various Nanomaterials for the Determination of Sulfonamides

Background:

The widespread applications of sulphonamides, as antibacterial or antimicrobial agents, and their mechanism of actions in the body, have changed their determination to an important issue in the area of human health.

Objective:

Here, history of developing voltammetric sensors based on nanomaterials for the detection of sulfonamides including sulfadiazine, sulfamethoxazole, sulfacetamide, sulfadimethoxine, sulfathiazole, sulfamethiazole and sulfamerazine is reviewed. Modified electrodes based on various nanomaterials (carbonaceous nanomaterials, Metallic Nanoparticles (MNPs), conducting nanopolymers) have been reported, and studies showed that nanomaterials have been mostly used to overcome problems like the poor sensitivity and selectivity of bare electrodes. The study covers the properties of each sensor in detail, and reports and compares the linear ranges, Limits of Detection (LODs), reproducibility, and reusability of the electrodes reported so far.

Ciprofloxacin degradation by first-, second-, and third-generation manganese porphyrins

A range of hydrophobic first-, second-, and third-generation manganese porphyrins (MnPs) was investigated as cytochrome P450 models for degradation of the antibiotic ciprofloxacin (CIP). The experiments were carried out under mild conditions; oxidants such as iodosylbenzene (PhIO), H₂O₂, and meta-chloroperbenzoic acid were employed. The PhIO system yielded the best results: CIP degradation ranged between 56% and 76%. CIP degradation was not directly related to MnP generation. The second-generation MnP afforded the best result with the advantage that it required less preparation effort as compared to the third-generation MnP. Some new degradation products in MnP-mediated ciprofloxacin degradation were proposed, and the products of the reaction are not cytotoxic under the conditions evaluated.

Silver-filled MWCNT nanocomposite as a sensing element for voltammetric determination of sulfamethoxazole

Here, we introduce a new electrode based on Silver-filled multi-walled carbon nanotube (Ag-MWCNT) and methyltrioctyl ammonium chloride (MTOAC) for highly sensitive voltammetric measurement of Sulfamethoxazole (SMX). The electrode showed an electrocatalytic activity as it led to the diminution of the overpotential and an increase in peak current for SMX oxidation in a phosphate buffer solution (pH 6.0). Analysis of surface topography and electrochemical properties of the modified electrode was examined by TEM, EDX and EIS, respectively. Electrochemical performance of the modified electrode was investigated with cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques for determination of SMX in aqueous solution. In addition, the oxidation process was found to be dependent on the pH of the buffer solution. Under optimal conditions, a linear relationship between the oxidation current and SMX concentration was found in a range 0.05-70 μM (R² = 0.997) with a detection limit of 0.01 μM after 2 min of accumulating time. The electrode was successfully used to quantify SMX in pharmaceutical formulations and human urine by DPV.

Delivering precision antimicrobial therapy through closed-loop control systems

Sub-optimal exposure to antimicrobial therapy is associated with poor patient outcomes and the development of antimicrobial resistance. Mechanisms for optimizing the concentration of a drug within the individual patient are under development. However, several barriers remain in realizing true individualization of therapy. These include problems with plasma drug sampling, availability of appropriate assays, and current mechanisms for dose adjustment. Biosensor technology offers a means of providing real-time monitoring of antimicrobials in a minimally invasive fashion. We report the potential for using microneedle biosensor technology as part of closed-loop control systems for the optimization of antimicrobial therapy in individual patients.

Manganese porphyrin sensor for the determination of bromate

The electro reductive behavior and determination of bromate on [5, 10, 15, 20-tetrakis (4-methoxyphenylporphyrinato] Manganese (III) chloride (TMOPPMn(III)Cl) modified Gold electrode(GE) was investigated by Square wave voltammetry (SWV). Bromate showed an irreversible reduction peak at -164 mV in 0.1 M pH 7 Na2SO4 solution. The cathodic peak of bromate showed a reduction in potential of 88 mV on modifying GE with a porphyrin film. The peak current varied linearly with concentration with a detection limit of 3.56 × 10(-9) M. The influence of pH, scan rate, supporting electrolyte and interferents on the reduction peak current of bromate were studied. The developed sensor was proposed for the determination of bromate in bread samples and compared with the standard method.

Electrocatalytic response of poly(cobalt tetraaminophthalocyanine)/multi-walled carbon nanotubes-Nafion modified electrode toward sulfadiazine in urine

A highly sensitive amperometric sulfadiazine sensor fabricated by electrochemical deposition of poly(cobalt tetraaminophthalocyanine) (poly(Co(II)TAPc)) on the surface of a multi-walled carbon nanotubes-Nafion (MWCNTs-Nafion) modified electrode is described. This electrode showed a very attractive performance by combining the advantages of Co(II)TAPc, MWCNTs, and Nafion. Compared with the bare glassy carbon electrode (GCE) and the MWCNTs-Nafion modified electrode, the electrocatalytic activity of poly(Co(II)TAPc)-coated MWCNTs-Nafion GCE generated greatly improved electrochemical detections toward sulfadiazine including low oxidation potential, high current responses, and good anti-fouling performance. The oxidation peak currents of sulfadiazine obtained on the new modified electrode increased linearly while increasing the concentration of sulfadiazine from 0.5 to 43.5 μmol/L with the detection limit of 0.17 μmol/L.

Voltammetric assay of anti-anginal drug nicorandil in different solvents

Voltammetric behaviour and assay of nicorandil were investigated using square-wave and cyclic voltammetry. Voltammograms in Britton-Robinson (BR) buffer exhibited one well-defined and two merged reduction peaks. The influence of different buffers, electrolytes, pH, scan rates, and concentration of the drug on cathodic peak current was studied. On the basis of electrochemical behaviour of nicorandil, a direct square-wave voltammetric procedure for quantitation of nicorandil has been developed and validated. The proposed square-wave voltammetric method allows quantitation over the range 12.5-62.5 µg mL(-1) with correlation coefficient of 0.992. The limit of quantification and limit of detection were 21.95 µg mL(-1) and 6.58 µg mL(-1) , respectively. Precision and accuracy were also checked and found within limits. The developed square-wave method has also been successfully applied for the determination of nicorandil in pharmaceutical formulations.