Preparation of Molecularly Imprinted Magnetic Graphene Oxide-Gold Nanocomposite and Its Application to the Design of Electrochemical Sensor for Determination of Epinephrine

Abstract

Recently, MIPs-based electrochemical sensors have attracted much attention because of their high selectivity, high sensitivity, small size and low prices. 23,24 Although MIPs prepared by the conventional method show high selectivity, they have some disadvantages, such as labor-intensive preparation process, complex preparation processes, low binding capacity, poorly available sites and slow kinetics. 25 Efforts to overcome these problems involvde the use of MIP-grafted GR-Ox sensors, which offer promising solutions for the research world of science. 26 For example, Mehdinia and colleagues have used GR-Ox as an electrochemically active substance and MIP as an element of identification in their sensor design. 27 In the last decade, metal nanoparticles have been used in the design of nanocomposites. 28,29 They have unique features including high adsorption capability, excellent electrical characteristics and small size. 30,31 Magnetic nanoparticles (MNPs) coated with 2019 In this study, a new molecularly imprinted polymer (MIP) based nanocomposite was synthesized then used to determine epinephrine (EPN) by the use of an electrochemical sensor modified by it. Typical techniques for the synthesis of MIP have disadvantages, such as weak binding sites, low mass transfer and low selectivity. One of the ways to improve electrochemical properties is the use of graphene oxide (GR-Ox) and modification of its surface. For this purpose, GR-Ox was initially magnetized (MGR-Ox), then its surface was coated with a silica layer, and gold nanoparticles (AuNPs) were coated on its surface. Subsequently, copolymerization of methacrylic acid (MAA) and N,N′-methylene-bis-acrylamide (MBA) in the presence of EPN was performed on the MGO-AuNPs surface. Afterwards, a selective carbon paste electrode (CPE) with synthetic nanocomposite was fabricated to detect EPN. Under optimal conditions, a linear range from 10 -8 to 5.0 × 10 -7 M was obtained for the measurement of EPN in urine and blood with a detection limit of 5 × 10 -9 M (S/N = 3).

Molecularly imprinted polymers (MIPs) based electrochemical sensors for the determination of catecholamine neurotransmitters – Review

“…The molecular imprinting was also able to prevent cross-reactivity between the two analytes with 100% adsorption of each analyte in the presence of interferents. Similarly, Mardani et al [61] reported imprinting factors of 8.14, 1.67, 1.4, 1.1, 1.73, and 2.9 for EP, isoproterenol, AA, UA, DA, and NE, respectively at EP imprinted MIP, magnetic graphene oxide and AuNPs modified CPE. The electrode was able to achieve such a feat because of its special affinity for EP.…”

“…DA and EP with similar structure interestingly have higher imprinting factor than other interferents. Mardani et al [61] further revealed that as high as 30-fold AA and DA concentration did not affect the DPV current response of the electrode towards EP.…”

“…Interestingly, this nanocomposite was present in the pre-polymerization mixture in a bid to achieve MIPs coated nanocomposite for CPE modification. Mardani et al [61] achieved this through the formation of MIPs-graphite powder paste in the presence of paraffin oil.…”

“…Bulk polymerization [76] PPy-CNTs-MIP Pyrrole Bulk polymerization [60] o-PD-MIP o-phenylenediamine (o-PD) Electro-Polymerization [60] MGO-AuNPs/MIP Methacrylic acid (MAA) Bulk polymerization [61] Pt/MIP Bis(2,2′-bithienyl)methanes (BBTMs) Electro-Polymerization [29] MIP/PIL-MWCNTs/ITO 3-ethyl-1-vinylimidazolium tetrafluoroborate (Ionic liquid) Electro-Polymerization [70] ZNRs/ITO/PET Pyrrole Electro-Polymerization [62] Norepinephrine Poly(o-AP)/GCE o-aminophenol (o-AP) Electropolymeri-zation [68] MIP-coated PdNPs Phenyl trimethoxy silane (PTMOS) Sol-gel [83] MIP/SWCNTs/GCE Antimony tin oxide doped silica (ATO-silica) Sol-gel [82] GNPs-fMWCNTs-OMNiDID/PGE Triamino triazine (TAT) Thermal-surface grafting from [28] of working electrodes. Interestingly, such working electrodes have turn out to be of better catalytic properties after such modification.…”

“…CPE was modified by Mardani et al with a MIP coated composite comprising of silica functionalized graphene oxide and AuNPs. [61] The GO in this matrix was essentially a magnetic GO (MGO) because it was initially prepared in the presence of iron (II) and (III) chlorides to confer magnetic properties. Through bulk polymerization involving methacrylic acid (MAA), N,N-methylene-bisacrylamide (MBA) and ammonium persulphate as functional monomer, crosslinker and initiator, respectively, MIPs were prepared in a solution of MGO-AuNPs earlier made with deionized water.…”