Electropolymerization of Molecularly Imprinted Polymer for The Detection of Vardenafil Hydrochloride /
Riham Kamal Ahmed Mohamed Soliman ; Rasha Mohamed Elnashar , Hussien M. Fahmy
- 2022.
Thesis (M.Sc.)-Cairo University- Faculty of Science - Department of Chemistry
Bibliography: p. 75-84.
For various experimental optimizations, the design of experiment approach has lately become an urgent demand. Not only to save money required for chemicals and equipment but also to reduce the time taken to run one-factor at a time tests to optimize the experimental conditions. Different analytical methods applied for food, environmental and pharmaceutical analysis can probably benefit from the use of design of experiments, as they are usually based on optimization of multiple variables. The use of experimental design has proven to be helpful in identifying and optimizing significant factors, as well as achieving appropriate results through running a limited number of experiments. Electrochemical sensors represent a class of analytical chemistry methodologies known to be quick, reliable, and inexpensive, with a wide range of applications. The review presented in this thesis intends to describe the most recent screening and optimization designs for the construction and operation factors of electrochemical sensors, as well as how they might be coupled effectively, for the period 2019-2021. Experimental designs can be used either for screening different operational variables, such as pH, ratio of components used for electrode modification, operational variables such as scan rate, step potential, pulse amplitude or accumulation time or potential. Also, upon reaching the most significant factors, different designs can be applied for optimization of such interactions. The thesis also involves the development of an electrochemical sensor by electropolymerizing pyrrole (Py) functional monomer and Vardenafil (VRL) mixture on a platinum electrode (PtE) after its modification using electrodeposited platinum nanoparticles (PtNPs). Then, the sensor was electrochemically overoxidized to produce overoxidized polypyrrol (OPPy) imprinted sensor of VRL. Vardenafil (VRL) is a pharmaceutical compound used for erectile dysfunction treatment. During the preparation of the sensor, seven variables were screened including VRL and pyrrole concentrations, no of polymerization scan cycles, time of incubation, incubation pH media and accumulation time potential. Unlike the traditional approaches of varying vi one factor at a time, fractional factorial design was firstly used to screen the most significant component, preceded by central composite design (CCD) optimization acquire a correlative perspective of the various interactions between these factors simultaneously. The sensor was examined topographically utilizing Scanning electron microscopy (SEM) and electrochemically using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The developed sensor demonstrated a linear range of concentrations from 1 × 10-12 M to 5 × 10-8 M by means of EIS in addition to the differential pulse voltammetry (DPV) providing very low LODs of 0.9 × 10-13 M and 2 × 10-13 M (S/N = 3), respectively.