Electrochemical determination of atypical antipsychotic drug quetiapine using nano-molecularly imprinted polymer modified carbon paste electrode.

In this research, the advantages of molecularly imprinted polymer (MIP) materials have been used to develop a new electrochemical sensor for determination of quetiapine (QTP) drug. MIP nanoparticles were synthesized by precipitation polymerization method and used as QTP recognition elements in the composition of modified carbon paste electrode (CPE) for selective and sensitive assay of this drug. Cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques were used for electrochemical analysis. Some parameters affecting the sensor performance were optimized and under optimal conditions, the proposed sensor showed linear responses with QTP concentration in the range of 1.6 × 10-8 to 2.5 × 10-6 M (R2 = 0.9964). The limits of detection (LOD) and quantification (LOQ) were calculated 5.04 × 10-9 M and 1.68 × 10-8 M respectively. Also, the amounts of %RSD for evaluation of repeatability and reproducibility of the proposed sensors were respectively obtained 2.19 and 3.02%. The method was successfully applied to determination of QTP in its pharmaceutical formulation and human urine samples.

Molecularly imprinted polymer nanoparticles-based electrochemical sensor for determination of diazinon pesticide in well water and apple fruit samples.

In this research, an electrochemical sensor based on molecularly imprinted polymer (MIP) nanoparticles for selective and sensitive determination of diazinon (DZN) pesticides was developed. The nanoparticles of diazinon imprinted polymer were synthesized by suspension polymerization and then used for modification of carbon paste electrode (CPE) composition in order to prepare the sensor. Cyclic voltammetry (CV) and square wave voltammetry (SWV) methods were applied for electrochemical measurements. The obtained results showed that the carbon paste electrode modified by MIP nanoparticles (nano-MIP-CP) has much higher adsorption ability for diazinon than the CPE based non-imprinted polymer nanoparticles (nano-NIP-CP). Under optimized extraction and analysis conditions, the proposed sensor exhibited excellent sensitivity (95.08 µA L µmol(-1)) for diazinon with two linear ranges of 2.5 × 10(-9) to 1.0 × 10(-7) mol L(-1) (R (2) = 0.9971) and 1.0 × 10(-7) to 2.0 × 10(-6) mol L(-1) (R (2) = 0.9832) and also a detection limit of 7.9 × 10(-10) mol.L(-1). The sensor was successfully applied for determination of diaznon in well water and apple fruit samples with recovery values in the range of 92.53-100.86 %. Graphical abstract Procedure for preparation of electrochemical sensor based on MIP nanoparticles for determination of diazinon.

Voltammetric sensor based on carbon paste electrode modified with molecular imprinted polymer for determination of sulfadiazine in milk and human serum.

A new sensitive voltammetric sensor for determination of sulfadiazine is described. The developed sensor is based on carbon paste electrode modified with sulfadiazine imprinted polymer (MIP) as a recognition element. For comparison, a non-imprinted polymer (NIP) modified carbon paste electrode was prepared. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods were performed to study the binding event and electrochemical behavior of sulfadiazine at the modified carbon paste electrodes. The determination of sulfadiazine after its extraction onto the electrode surface was carried out by DPV at 0.92 V vs. Ag/AgCl owing to oxidation of sulfadiazine. Under the optimized operational conditions, the peak current obtained at the MIP modified carbon paste electrode was proportional to the sulfadiazine concentration within the range of 2.0×10(-7)-1.0×10(-4) mol L(-1) with a detection limit and sensitivity of 1.4×10(-7) mol L(-1) and 4.2×10(5) µA L mol(-1), respectively. The reproducibility of the developed sensor in terms of relative standard deviation was 2.6%. The sensor was successfully applied for determination of sulfadiazine in spiked cow milk and human serum samples with recovery values in the range of 96.7-100.9%.