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 as monomer, which cross-linked using ethylene glycol dimethacrylate and multiwalled carbon nanotubes (MWCNTs) as a modifier. The different factors were optimized, such as ratio of MIP components, percentage of MWCNT, pH, accumulation time, accumulation potential and scan rate. The proposed sensor was characterized using electrochemical impedance spectroscopy, Fourier-transform infrared spectroscopy, and Brunauer–Emmett–Teller. DPV was applied to obtain the calibration curve and optimization of different factors, the proposed sensor shows a wide linear range of 1х10-12M (0.47ng/L) to 1х10-7M (47.26µg/L) and limit of detection (LOD)1х10-13M (0.05ng/L) while the limit of quantification (LOQ) was found to be 3.3х 10-13M (0.16ng/L) in addition to good reproducibility and selectivity.

A novel molecularly imprinted polymer (MIP) based electrochemical sensor was developed for differential pulse voltammetric detection of silodosin (SLD), used for enlarged prostate (benign prostatic hyperplasia; BPH) treatment. A computational design was first applied for optimization of the molar ratio between silodosin (SLD, template): Methacrylic acid (MAA, functional monomer), based on which five polymeric ratios were prepared followed by testing the amount of crosslinker (ethylene glycol dimethacrylate (EGDMA)), imprinting and rebinding efficiency of the polymer. The ratio 1:4:20 was found to have the highest binding capacity for SLD, and thus, was used as a modifier for the development of modified carbon paste electrodes in presence of multiwalled carbon nanotubes (MWCNT). The sensor was electrochemically characterized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements and morphologically using SEM, TEM and BET and its performance was optimized in terms of amounts of MIP, MWCNT, pH and other electrochemical parameters. A linear response range of 1.0 × 10 À 12 -1.0 × 10 À 3 M SLD with a detection limit (S/N = 3) of 1.0 × 10 À 13 M was shown. Finally, the MIP-modified carbon paste sensor was successfully used to determine SLD in pure solutions, pharmaceutical formulations and spiked serum and urine samples.

Saxagliptin (Saxa) belongs to a new generation of antidiabetic pharmaceutical compounds used in combination with healthy diet and exercise to lower blood glucose levels in patients with type 2 diabetes mellitus (T2DM). In this work, we report for the first time a molecularly imprinted polymer (MIP) based electrochemical sensor for the determination of Saxa. Computational calculations were performed, based on which five MIPs were synthesized using Saxa as a template, itaconic acid as a monomer, crosslinked with ethylene glycol dimethacrylate and Di methyl sulfoxide (DMSO) as a porogen with different ratios. Non‐covalent interaction (NCI) analysis has been also conducted, and the obtained isosurface analysis was used for graphical visualization of NCI that could occur in real space as well as for the discrimination between hydrogen bond interaction, Van Der Waals attraction and spatial repulsion. The optimized polymer was incorporated as a modifier for designing an electrochemical sensor comprising MIP and Multiwalled carbon nanotubes (MwCNT) within carbon paste electrode (CPE). The operational variables including incubation time, pH, scan rate, and accumulation time were optimized. The sensor showed linearity over the concentration range (1 × 10−9–1 × 10−15 M) with low limit of detection (LOD) 8 × 10−16 and 2 × 10−16 M on using DPV and EIS, respectively. The sensor was successfully applied for pharmaceutical formulations, urine, and human serum samples with recovery range between 97.45–100.64 %.