Synthesis and Application of Glibenclamide Imprinted Polymer for Solid Phase Extraction in Serum Samples Using Itaconic Acid as Functional Monomer

Molecularly-Imprinted SERS: A Potential Method for Bioanalysis

The most challenging step in developing bioanalytical methods is finding the best sample preparation method. The matrix interference effect of biological sample become a reason of that. Molecularly imprinted SERS become a potential analytical method to be developed to answer this challenge. In this article, we review recent progress in MIP SERS application particularly in bioanalysis. Begin with the explanation about molecular imprinting technique and component, SERS principle, the combination of MIP SERS, and follow by various application of MIP SERS for analysis. Finally, the conclusion and future perspective were also discussed.

Microsphere molecularly imprinted solid-phase extraction for diazepam analysis using itaconic acid as a monomer in propanol

Diazepam (DZP) is a benzodiazepine drug used as an anti-drug and sedative. It is often misused to induce or create euphoria in combination with other drugs (high or fly sensation) or administered alone. So far, screening for DZP abuse with sensitive analytical methods is needed, as its small concentrations make it difficult to detect. Increased sensitivity of the analytical method can be obtained by using a preparation method that selectively separates the analyte from the sample matrix. Molecularly imprinted polymer (MIP) is one of the preparation solutions with good selectivity, specificity, and sensitivity. MIP was made from DZP as a template, itaconic acid, and ethylene glycol dimethacrylate in a composition of 1:4:20. MIP was made by precipitation polymerisation to obtain microsphere polymer type. MIP had a binding capacity value of 0.0557 mg/g and followed the Freundlich isotherm. Application of the microsphere MIP on spiked blood serum resulted in a recovery of 105.63 ± 1.0% for MIP compared to 21.28 ± 0.4% for non-imprinted polymer, with the imprinting factor value reaching 4.96. Hence, MIP DZP with itaconic acid as a functional monomer and propanol as a porogen, fabricated by the precipitation polymerisation method, is a promising sorbent for DZP extraction in biological fluids.

Synthesis of Diazepam-Imprinted Polymers with Two Functional Monomers in Chloroform Using a Bulk Polymerization Method

Diazepam is a benzodiazepine that has the potency to be misused because it is effective, easily obtained, and inexpensive. The misuse of diazepam is to replace illegal drugs and be a sedative. Separation of diazepam is needed to detect possible drug abuse and to monitor drug levels in blood to ensure the effectiveness of the drug. This study was conducted to obtain a molecularly imprinted solid-phase extraction (MI-SPE) sorbent to separate diazepam from serum samples. This work started at the synthesis stage with the bulk polymerization method, using methyl methacrylate and acrylamide as functional monomers, diazepam as a template, and ethylene glycol dimethacrylate as a crosslinker. The polymer obtained was identified by its adsorption capacity and packaged into a solid-phase extraction (SPE) cartridge, and the extraction conditions were optimized. The optimization results were then used to extract diazepam from the serum sample. The test results showed that the adsorption ability of the molecularly imprinted polymer (MIP) with the functional monomer, methyl methacrylate, was 63.98 ± 0.1%, which is higher than that of the acrylamide MIP monomer, with a value of 43.27 ± 0.1%. The MIP sorbent of methyl methacrylate was applied to the SPE with 200 mg of polymer in a 3 mL cartridge. Diazepam added to serum samples were then passed through the MIP-SPE producing a percent recovery value of 95.31 ± 1.1% for MIP and 60.83 ± 0.3% for nonimprinted polymer (NIP). The results showed that the MI-SPE sorbent made from the monomer methyl methacrylate gave higher extraction recovery results than acrylamide, and it could be used for extracting diazepam from serum samples with or without other substances.

Synthesis of Atenolol-Imprinted Polymers with Methyl Methacrylate as Functional Monomer in Propanol Using Bulk and Precipitation Polymerization Method

Atenolol is one of the beta-1 blocker drugs that is misused by athletes to increase their performance during competition. Therefore, it is important to analyze atenolol levels in blood selectively. The preparation method that can be used in separating atenolol in sample is molecular imprinting solid-phase extraction (MI-SPE) because it has good selectivity and sensitivity. This study aims to examine the characteristics and analytical performance of imprinted polymers synthesized from functional monomer methyl methacrylate. The stages of this study include the determination of association constants, synthesis of sorbent MI-SPE atenolol using the bulk polymerization method, and precipitation with atenolol as the template, methyl methacrylate as the functional monomer, and propanol as the porogen. The template was extracted from a polymer, and then, the adsorption ability, capacity, and selectivity of MI-SPE and finally the application of the best MI-SPE to spiked serum samples were determined. MI-SPE was also characterized by using Fourier-transform instrument infrared (FTIR) and scanning electron microscope (SEM). The result of characterization with FTIR and SEM showed that MIP made by the precipitation polymerization method was completely polymerized, more porous, and produced smaller particle size with an average value of 0.274 μm. It had better analytic performances than MIP made by bulk polymerization, with affinity value 0.3607 mg/g and homogeneity value 1.3246, and good selectivity toward atenolol with imprinting factor value 22.519. Application of MI-SPE to spiked serum samples has an excellent recovery percentage of 95.46% over 0% for the nonimprinting one. Based on the result of study, MIP made by precipitation polymerization could be used to extract atenolol on serum samples toward drug analysis.

Extraction of atenolol from spiked blood serum using a molecularly imprinted polymer sorbent obtained by precipitation polymerization

Atenolol (ATE) is a cardio-selective β-blocker that is used in the treatment of hypertension over extended periods. However, ATE, like propranolol, has major potential for misuse as a performance-enhancing drug in several sports. Therefore, an efficient and selective separation method is required to detect and monitor the level of ATE in the body. This paper presents a molecularly imprinted polymer with specific and selective binding to ATE using precipitation polymerization. We show that when employed in an optimized molecular imprinted solid phase extraction (MI-SPE) protocol, recoveries of 93.65 ± 1.29% from spiked blood serum with excellent discrimination from other β-blocker drugs is possible. The methodology used in this study includes molecular modeling interaction between ATE and itaconic acid (ITA) as functional monomer, followed by determination of binding constants with spectrophotometry, synthesis of the polymer using precipitation polymerization and ending with characterization and application of polymers to extract ATE in serum. Docking analysis revealed a binding affinity between ATE and ITA of −2.0 kcal/mol with the formation of hydrogen bonding. The association constant between ATE and ITA was studied by UV titration in two different solvents, with evidence of an association constant 6.277 × 10² M⁻¹ measured in acetonitrile: methanol (1:1). An optimized MI-SPE protocol was developed for the extraction of ATE from spiked blood serum, obtaining recoveries of 93.65% with excellent selectivity toward other β-blocker drugs.