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. 2022 Sep 8;7(37):32988-32995.
doi: 10.1021/acsomega.2c02250. eCollection 2022 Sep 20.

Molecularly Imprinted Polymer Modified with an MWCNT Nanocomposite for the Fabrication of a Barbital Solid-Contact Ion-Selective Electrode

Layla M S Al Shagri  1 , Ayman H Kamel  1   2 , Hisham S M Abd-Rabboh  3 , Majed A Bajaber  3
Affiliations

Molecularly Imprinted Polymer Modified with an MWCNT Nanocomposite for the Fabrication of a Barbital Solid-Contact Ion-Selective Electrode

Layla M S Al Shagri et al. ACS Omega. .

Abstract

For potentiometric sensing of barbital (BAR), unique micro-sized imprinted polymer/multiwalled carbon nanotube (MWCNT)-based sensors are introduced. MWCNT is a lipophilic ion-to-electron transducing substance. A synthetic, described, and integrated barbital sodium molecular imprinted polymer (MIP) was used as a recognition receptor for potentiometric transduction in a plasticized polyvinyl chloride membrane. Methacrylic acid and ethylene glycol dimethacrylic acid are used as the functional monomer and crosslinking agent, respectively, in the synthesis of the MIPs. In the operating concentration range of 1.0 × 10-3 to 2.0 × 10-7 M, the sensors' Nernstian slope was -56.8 ± 0.9 mV/decade, with a detection limit of 1.0 × 10-7 M. The sensor displayed an accurate response time of 10 s and consistent potential response in the pH range of 8.5-11. Using chronopotentiometry tests, the interfacial capacitance of the presented ion-to-electron transducer was assessed. When compared to sensors without MWCNTs, the interfacial double-layer capacitance for sensors based on those layers reached 52.5 μF. After the addition of the MWCNTs nanocomposite layer, the water layer was eliminated between the sensing membrane and the conducting substrate. A wide range of applications for the proposed sensors for BAR detection in real samples can be provided by the sensors' strong selectivity over the interfering species. The suggested sensors were successfully used to determine BAR in urine samples that had been spiked.

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Conflict of interest statement

The authors declare no competing financial interest.

Figures

Figure 1
Figure 1
SEM photographs of MIPs (A) and NIPs (B) in acetonitrile solvent. [Mag. = 10.00 kx; EHT = 5.00 kV; WD = 6.9 mm].
Figure 2
Figure 2
(A) Adsorption isotherms and (B) Scatchard plots for both MIP and NIP beads.
Figure 3
Figure 3
Adsorption selectivity of MIPs and NIPs to BAR, PBAR, and PHBAR.
Figure 4
Figure 4
Calibration plots for both MIP and NIP membrane-based sensors.
Figure 5
Figure 5
Calibration curves of the presented sensors (A) with and (B) without the MWCNT intermediate layer, determined in time.
Figure 6
Figure 6
Reversibility of the potential response measured in BAR solutions with concentrations: 1.0 × 10–5, 1.0 × 10–4, and 1.0 × 10–3 M for the presented sensors: (A) GC/MIPs/BAR-ISE and (B) GC/MWCNTs/MIP/BAR-ISE.
Figure 7
Figure 7
Water-layer test for the presented sensors: (A) GC/MIPs/BAR-ISE and (B) GC/MWCNTs/MIP/BAR-ISE. The measurements were recorded in 1.0 × 10–3 M BAR and 1.0 × 10–2 M NaCl.
Figure 8
Figure 8
Effect of light, O2, N2, and CO2 on the SPE/MWCNTs/MIP-ISE.
See this image and copyright information in PMC

References

    1. Swarbrick J.Encyclopedia of Pharmaceutical Technology, 3rd ed.; CRC Press: Boca Raton, FL, USA, 2013.
    1. Yasiry Z.; Shorvon S. D. How phenobarbital revolutionized epilepsy therapy: The story of phenobarbital therapy in epilepsy in the last 100 years. Epilepsia 2012, 53, 26–39. 10.1111/epi.12026. - DOI - PubMed
    1. López-Muñoz F.; Ucha-Udabe R.; Alamo C. The history of barbiturates a century after their clinical introduction. Neuropsychiatr. Dis. Treat. 2005, 1, 329. - PMC - PubMed
    1. Ito T.; Suzuki T.; Wellman S. E.; Ho K. Pharmacology of barbiturate tolerance/dependence: GABAA receptors and molecular aspects. Life Sci. 1996, 59, 169–195. 10.1016/0024-3205(96)00199-3. - DOI - PubMed
    1. Vlasses P. H.; Rocci M. L.; Koffer H.; Ferguson R. K. Combined phenytoin and phenobarbital overdose. Drug Intell. Clin. Pharm. 1982, 16, 487–488. 10.1177/106002808201600606. - DOI - PubMed