Recent Trends in Ibuprofen and Ketoprofen Electrochemical Quantification - A Review

Non-steroidal anti-inflammatory drugs are intensively manufactured, used, and regulated. However, these compounds incur toxic effects on gastrointestinal, cardiovascular, and renal systems when administered in high doses for extended periods. Additionally, once these drugs reach the ecosystems through various pathways, they become environmental contaminants and raise ecological concerns. Traditional detection methods proposed for non-steroidal anti-inflammatory drugs detection encompass certain limitations. In this context, the need for simple, cost-effective, sensitive, and selective detection methods that could improve the quality of analysis led the attention of the scientific community toward electrochemical sensors. The lowest limit of detection of ibuprofen (33.33 × 10-12 μmol L-1) was recorded for a sensor based on ibuprofen specific aptamer bound with nitrogen-doped graphene quantum dots and gold nanoparticles nanocomposite modified glassy carbon electrode using differential pulse voltammetry, while the lowest limit of detection reported for ketoprofen was 0.11 μmol L-1 when differential pulse voltammetry was used. This review focuses on the construction, analytical performances, and applicability of electrochemical sensors developed for ibuprofen and ketoprofen determination. This work covers 24 articles published between 2016 and 2022.

Mini-Review: Electrochemical Sensors Used for the Determination of Water- and Fat-Soluble Vitamins: B, D, K

Vitamins are one of the most essential organic compounds that are necessary for the human body, in order to develop and grow in a healthy way. The aim of this mini-review is to bring together a series of electrochemical sensors (voltametric and amperometric) developed for the determination of vitamins from the families of B, D and K in biological, pharmaceutical or food-related samples. For this mini-review, 16 articles published between 2016 and 2021 were taken into consideration.

An ultrasensitive electrochemical platform based on copper oxide nanoparticles and poly (crystal violet) for the detection of brilliant blue FCF from soft drinks

In this study, a highly sensitive and quick electrochemical platform based on poly (crystal violet) film and copper oxide nanoparticles for the detection of brilliant blue FCF from various soft beverages was developed. The synthesized copper oxide nanoparticles were investigated with Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray. Further, crystal violet was electropolymerized on the surface of the carbon paste electrode modified with copper oxide nanoparticles. The electrochemical properties of poly (crystal) violet/copper oxide nanoparticles modified carbon paste electrode were assessed through the utilization of cyclic voltammetry and electrochemical impedance spectroscopy. Furthermore, the signal towards the oxidation of brilliant blue was examined using the differential pulse voltammetry method. Under ideal experimental conditions, the peak current exhibited a linear relationship with the brilliant blue concentration within the range of 0.01-1.00 nmol/L, with a sensitivity of 294.55 µA nmol/L cm-2 and a significant detection limit of 3 pmol/L. In the presence of other dyes and other food additives, the developed platform showed greater selectivity in detecting brilliant blue. The reliability of the designed platform was demonstrated by the 99.19 - 100.67 recovery percentage for the identification of BB in various soft drink samples.

Stochastic platform based on calix[6]arene and TiO2-modified reduced graphene oxide electrode for on-site determination of nonivamide in pharmaceutical and water samples

Using a detection platform based on an integrated sensor constructed by modifying TiO₂ and reduced graphene oxide paste with calix[6]arene, a novel stochastic approach for both quantitative and qualitative analysis of nonivamide in pharmaceuticals and water samples has been developed. A wide analytical range of 1.00 × 10^-18 to 1.00 × 10^-1 mol L^-1 was obtained with the stochastic detection platform for nonivamide determination. A very low limit of quantification of 1.00 × 10^-18 mol L^-1 was reached for this analyte. The platform was successfully tested on real samples, respectively, on topical pharmaceutical dosage form and surface water samples. The samples were analyzed without pretreatment in the case of pharmaceutical ointment or under minimal preliminary processing for surface waters proving a facile, rapid, and reliable method. Moreover, being portable, the developed detection platform is adequate for on-site analysis in various sample matrices.

Electrochemical platform based on molecularly imprinted polymer with zinc oxide nanoparticles and multiwalled carbon nanotubes modified screen-printed carbon electrode for amaranth determination

A novel electrochemical platform for amaranth determination has been developed using a rapid, easy, inexpensive, and portable molecularly imprinted polymer technique. The MIP platform was fabricated by electropolymerizing melamine as monomer in the presence of amaranth as template on the surface of ZnO-MWCNT/SPCE. Then, amaranth was completely eluted, leaving imprinted cavities in the polymeric film that could effectively recognize amaranth in solution. The electrochemical platform based on a molecularly imprinted polymelamine was analyzed by scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). Under optimum conditions, the developed MIP/ZnO-MWCNT/SPCE platform can be properly used for amaranth determination, with high sensitivity of 96.2 µA µM cm^-2, two linear concentration ranges (0.01 to 1 µM and 1 to 1000 µM) and a low limit of detection of 0.003 µM. The anodic peak potential of amaranth was found to be 0.73 V. Additionally, the polymelamine MIP films specifically recognize amaranth molecules, making it possible to detect amaranth in a complex solution with high selectivity, excellent repeatability, reproducibility, and stability. The MIP/ZnO-MWCNT modified screen-printed carbon electrode was successfully applied to determine amaranth in pharmaceutical and water samples, with recovery values ranging from 99.7 to 102% and RSD% values less than 3.2%.

Simultaneous determination of anthracene and phenanthrene using a poly-alizarin red S/carbon paste electrode

A polymer-based carbon paste electrode was constructed by electropolymerized Alizarin Red S (ARS) film on the carbon paste electrode (CPE) surface. The electrochemical properties of poly-ARS/CPE were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Scanning electron microscopy (SEM) was utilized for electrode characterization. The electropolymerization cycles for the construction of the sensor and the supporting electrolyte were optimized. With 0.1 M LiClO₄ as a supporting electrolyte, poly-ARS/CPE was able to generate oxidation peaks for anthracene (ANT) and phenanthrene (PHE), that were clearly defined and easily distinguished from one to another when operating in square wave voltammetry (SWV). In the simultaneous detection the linear ranges of ANT and PHE were within 80-1000 μM, with detection limits of 24 μM. The variation of peak parameters with scan rate was investigated to determine the nature of electrooxidation and the number of electrons involved in the electrode process. Poly-ARS/CPE was successfully utilized for the detection of ANT and PHE in different water samples and the obtained results suggested the selectivity, stability and reproducibility of the modified electrode.

Fast screening method for early diagnostic of gastric cancer based on utilization of a chitosan - S-doped graphene - based needle stochastic sensors

Needle stochastic sensors were developed for the assay of carbohydrate antigen 19-9 (CA 19-9) and carcinoembryonic antigen (CEA) in different biological samples (e.g., whole blood, tissues, urine, and saliva). Sulfur doped graphene powders were modified with chitosan; paraffin oil was added to form a homogeneous paste that was used as active side of the stochastic sensors. High sensitivities and low limits of determination were achieved for the assay of CA19-9 and CEA in biological samples. The validation of the proposed screening method (which is utilizing the stochastic sensors as screening tools) was made by using real biological samples obtained from confirmed patients with gastric cancer; very good correlations for the concentrations of CEA and CA19-9 were obtained using the needle stochastic sensors.