Application of Molecularly Imprinted Poly-Itaconic/Multiwalled Carbon Nanotubes for Selective and Sensitive Electrochemical Detection of Linagliptin

Abstract

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.

Application of a Gold /Poly(Congo Red) Modified Electrochemical Sensor Toward Fast and Reliable Detection of the Oxazolidinone Fungicide Famoxadone in Vegetables

“…Figures 8C, 8D shows a linearity between peak current and square root of scan rate for bare GCE and AuNPs/ poly(CR)/GCE, which indicates that the process is diffusion controlled as expected for this catalytic system with two regression equations: І p = 10.391 + 4.674 υ 1/2 with (R 2 = 0.984) and І p = −7.166 + 8.081 υ 1/2 with (R 2 = 0.999) for bare GCE and AuNPs/ poly(CR)/GCE, respectively. 35,53,54 The effective surface area of electrodes was calculated using Randles-Sevcik equation Eq. 2.…”

“…8E was shown to be linear with a regression equation presented as: Log[І p ] = 0.817 + 0.52 log [υ] with correlation coefficient (R 2 = 0.998) and the slope was found to have a value 0.52 which is in quite close to the theoretical value of 0.5 which indicated a diffusion-controlled process. [53][54][55] Interference studies.-The performance of AuNPs/poly(CR) towards FAM in the presence of other classes pesticides, Cymoxanil, Fluopicolide, Azoxystrobin, Chloropyrifos, Imidacloprid, Penconazole, Kasugamycin, that might exist in the same environment was examined. DPV was performed for solutions containing 1 μM FAM mixed with different ratios 1:1, 1:10 and 1:100 of the tested interferents As given in Table I, it is clear from the given data that no significant changes (±5%) were recorded in the peak currents of FAM oxidation at the different tested ratios, which revealed that the AuNPs/Poly(CR)/GCE has acceptable selectivity with respect to FAM.…”

Application of Molecularly Imprinted Electrochemical Sensor for Selective Non-Labelled Detection of Acetamiprid Insecticide in Fruits

“…Student's t and F-tests were utilized for carrying out the statistical analysis of data to evaluate the difference in the mean of the analysis results and the standard reference methods as (HPLC method with 3 tested samples of ACP pure solution, EIS method with 2 tested samples of spiked apple solution, and DPASV method with 3 tested samples of spiked tomato solution) [ 22,40,42] for the obtained data for detecting the pure ACP and spiked vegetable samples (apple and tomato) respectively, as shown in Table IV, the tabulated values were higher than the calculated results, which reflects the high accuracy of the proposed sensor and its reliability and precision in comparison with the reference method.…”

“…MIP technology involves designing artificial receptors with a predetermined selectivity and specificity for a given analyte, that can be applicable in various fields, including purification, separation, drug delivery, detection/sensors, catalysis, and water analysis/treatment. 28,42,43 The use of MIP can provide qualitative or quantitative information on the presence of the target molecules (contaminants or nutrients) in a tested matrix. Thus, they can efficiently reduce the negative effects of some substances affecting food quality without significantly altering their organoleptic properties.…”

Design and application of molecularly imprinted electrochemical sensor for the new generation antidiabetic drug saxagliptin

“…The physical and catalytic properties of CNTs turned them ideal as composite modifiers in polymeric films, solar and fuel cells and electrochemical sensors. They were also reported to exhibit excellent chemical, thermal, and mechanical properties flexibility, and electrical conductivity which promotes their catalytic activity and charge transfer enhancement especially when incorporated in carbon paste electrodes [54][55][56]. Recently, MWCNT were used as modifiers in different electrochemical sensors for the detection of many analytes including: rutin [57], food azo dyes [58], pesticides [59] and vitamin D3 [60].…”