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For the first time, a green ecofriendly approach is applied, to develop a molecularly imprinted polymer (MIP) electrochemical for the assay of the oral anti-viral molnupiravir (MLN) in various matrices as confirmed by referring to analytical eco-scale, green analytical procedure index (GAPI), Raynie and Driver, analytical greenness metric (AGREE), and national environmental index (NEMI). AuNPs were chronoamperometry deposited on the glassy carbon electrode surface (GCE) using 0.01 gm ml−1gold solution (HAuCl4.3H2O) in 0.5 M H2SO4at a constant potential of −0.4 V for 60 s. Then, the MIP was created by electropolymerizing OPDA on the surface of AuNPs GCE using cyclic voltammetry in the potential range between −0.5 and +1 V for 15 cycles (scan rate: 50 mV.s−1). To optimize the sensor’s performance, factors such as number of electropolymerization cycles, template: monomer ratio, binding and rebinding time, pH of rebinding buffer, extraction solvent, deposition time of Au nanoparticles, order of deposition on the electrode; surface, as well as differential pulse voltammetry parameters including accumulation potential and time, and potential step, were all investigated. The detection limit was set at 0.00098 ng ml−1(3 × 10−12M) and the linearity range of MLN was between 0.033 ng ml−1and 164 ng ml−1(1 × 10−10–5 × 10−7 M). The MIP sensor was employed for MLN determination in its pharmaceutical product (capsules), spiked human plasma, and human urine samples with mean recovery % ± mean relative standard deviation (RSD) (99.82% ± 0.53), (99.88% ± 0.62), and (97.90% ± 0.70), respectively. The investigated sensor provided good reproducibility, repeatability, and durability. Acceptable selectivity regarding MLN when mixed with structurally comparable compounds was proved with mean recovery % ± mean RSD (97.10% ± 0.03). Additionally, when molnupiravir was exposed to oxidative, hydrolytic, and thermal stress conditions, good results in stability-indicating studies served as an indicator of sensor selectivity. The developed electrode is coupled with a portable potentiostat, making it a promising point-of-care diagnostic platform for on-site measurements.

We report a highly uniform nanocomposite of polyglutamic acid (PGA) and gold nanoparticles (AuNPs) electrodeposited on a recycled battery graphite electrode (BGE) for the detection of Nalbuphine (NB), a semi-synthetic opioid. The sensor was optimized and characterized morphologically (via scanning electron microscopy, atomic force microscopy, and energy dispersive X-ray analysis) and electrochemically (via cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy). Under optimized conditions, the PGA/AuNPs/BGE revealed two linear ranges, 2.5 × 10−8to1.0 × 10−6 M, and 2.0 × 10−6to 1.0 × 10−4 M for Nalbuphine (NB), that is equivalent to 9.825 × 10−3to 0.393 μg ml−1and 0.786 to 39.30 μg ml−1, with R2= 0.995 and 0.994, respectively, and showed good catalytic activity for the determination of nalbuphine in the presence of tramadol and the oxidation potential of these opioid analgesic drugs were separated. The sensor was successfully applied for the detection of NB in its pharmaceutical formulations, spiked urine, and human plasma samples, without applying any sample pretreatment, at a recovery range of 99 ± 0.03 to102 ± 0.02% and thus, the developed can be considered as a promising approach for NB abuse testing in clinical and forensic agencies.

In this work, the synthesis and optimization of an electrochemical sensor based on gold nanoparticles (AuNPs)/ conducting poly Congo red dye (poly(CR)) nanocomposite is reported and applied for detection of the Oxazolidinone fungicide famoxadone (FAM), which is considered as an environmentally hazardous material on excessive uncontrolled application. The modified sensor was characterized electrochemically using Cyclic Voltammetry (CV) and electrochemical impedance spectroscopy (EIS) to investigate the nature of charge transfer upon modification. Also, the topography of the sensor was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and energy dispersive X-ray spectroscopy (EDX). Two linear ranges 0.001–1 μM (0.37–374.40) μg l−1and 3–100 μM (1.12–37.44) mg l−1were recorded using AuNPs/poly (Congo Red)/GCE sensor for FAM with limit of detection (LOD) of 0.17 nM (0.06 μg l−1) and limit of quantification (LOQ) of 0.48 nM (0.18 μg l−1). The tested sensor showed good stability, reproducibility, and repeatability, in addition, sufficient selectivity towards FAM in presence of other tested pesticides. Finally, the fabricated sensor was applied for the determination of FAM in vegetable and formulation samples, with recovery range 98.9%–105.4% and RSD 0.70%–4.46%. ). Thus, this approach can be efficiently applied in regulatory authorization for tracing the Fam concentration, being very simple, portable, cost effective and easy to operate compared to chromatographic detection, thus allows fast decisions for regulatory authorities.

In this work, we report the first molecularly imprinted polymer (MIP) based electrochemical sensor for the determination of the antidiabetic drug Linagliptin (LNG) in pure sample, tablets, and spiked human urine and serum samples. Using a graphite electrode, differential pulse voltammetry (DPV) was applied to study the electrochemical behavior of LNG in a Britton Robinson (BR) universal buffer of pH 8 with Ag/AgCl electrode and Pt wire. The sensor is based on the modification of the traditional carbon paste sensor with Itaconic acid (IA) as monomer, which cross-linked using ethylene glycol dimethacrylate (EGDMA) and multiwalled carbon nanotubes (MWCNTs) as a modifier. The different factors were optimized, such as ratio of MIP components, percentage of multiwalled carbon nanotubes (MWCNT), pH, accumulation time, accumulation potential and scan rate. The proposed sensor was characterized morphologically using: Scanning electron Microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and Brunauer–Emmett–Teller (BET) and electrochemically applying electrochemical impedance spectroscopy (EIS)and cyclic voltammetry (CV). DPV was applied to obtain the calibration curve and optimization of different factors, the proposed sensor shows a wide linear range of 1 × 10−12M (0.47 ng l−1) to 1 × 10−7M (47.26 μg l−1) and limit of detection (LOD)1 × 10−13M (0.05 ng l−1) while the limit of quantification (LOQ)was found to be 3.3 × 10−13M (0.16 ng l−1) in addition to good reproducibility and selectivity.