98
FTIR and Raman spectroscopy are vibrational spectroscopic techniques that provide characteristic fundamental vibrations used to elucidate molecular structures.
FTIR can provide information about molecular vibration, which depends on the
masses of atoms, their geometric arrangement and the strength of the chemical
bonds, observed because of the absorption of IR radiation. Raman spectroscopy is
based on inelastic scattering of monochromatic light that interacts with molecular
vibrations in the system. Although these techniques arise from different processes,
they provide a complementary structural fingerprint for the characterization or identification of molecules (Zaidi 2017).
FTIR spectra provide information about the presence or absence of a functional
group that allows monitoring the polymerization stage (Molinelli et al. 2005), the
confirmation of the binding of the template of the imprinted sites (GutiérrezClimente et al. 2016) or even the successful removal of the template from the MIP
(Liu et al. 2015). Surface enhanced Raman spectroscopy (SERS) emerged as a
highly sensitive technique for MIP characterization. Xue et al. (2013) combined
FTIR and SERS for the characterization of surface-imprinted core-shell Au NPs for
the selective detection of bisphenol A.
Ultraviolet-visible (UV-Vis) and fluorescence spectroscopies have been used for
recording changes in wavelengths and intensity of absorption bands due to template
recognition. Fan and Wang (2010) monitored by means of UV-Vis spectroscopy the
coordination interactions between the template and a metal in the development of
the selective recognition of a metal coordination imprinted polymer to quercetin.
Zhang et al. (2012) demonstrated the selectivity for the protein template over the
analogues by fluorescence change of MIP-coated quantum dots with template.
Elemental analysis is regularly used to obtain information about the polymer
yield on the surface of a solid support. The elemental composition is essentially carried out by carbon, hydrogen and nitrogen analysis, but in some instances also oxygen and sulfur. A known amount of a substance is converted into simple and known
compounds containing only the element to be quantified. Carbon and hydrogen are
determined by instantaneous oxidation by oxygen combustion of carbon dioxide
and water, while nitrogen-containing compounds are converted into nitrogen gas
(Sellergren and Hall 2001). Regarding microelemental analysis, it is usually performed by energy dispersive X-ray spectroscopy (EDX) or X-ray photoelectron
spectroscopy (XPS), obtaining information about the surface elementary composition and elemental mapping of MIP particles (He et al. 2010). EDX is widely applied
to check the composition of Fe 3 O 4 NPs in order to confirm the synthesis of Fe 3 O 4
NPs (Lahcen et al. 2016). Luo et al. (2014) developed a novel graphene-molecular
imprinted polymer composite to determine electrochemically bovine hemoglobin.
The XPS spectrum, combined with FTIR and SEM, allowed to deduce that a layer
of poly(dopamine) polymer was successfully formed on the graphene surface.
Gel permeation chromatography (GPC), also known as size exclusion chromatography (SEC), is the most commonly used technique for Mw determination
of polymers, which is based on size-exclusion phenomena. This technique provides the M w and the M n and requires calibration with polymers of known Mw,
such as PS standards (Wulff et al. 2006). Similarly, this technique was also used
A. Gómez-Caballero et al.
FTIR and Raman spectroscopy are vibrational spectroscopic techniques that provide characteristic fundamental vibrations used to elucidate molecular structures.
FTIR can provide information about molecular vibration, which depends on the
masses of atoms, their geometric arrangement and the strength of the chemical
bonds, observed because of the absorption of IR radiation. Raman spectroscopy is
based on inelastic scattering of monochromatic light that interacts with molecular
vibrations in the system. Although these techniques arise from different processes,
they provide a complementary structural fingerprint for the characterization or identification of molecules (Zaidi 2017).
FTIR spectra provide information about the presence or absence of a functional
group that allows monitoring the polymerization stage (Molinelli et al. 2005), the
confirmation of the binding of the template of the imprinted sites (GutiérrezClimente et al. 2016) or even the successful removal of the template from the MIP
(Liu et al. 2015). Surface enhanced Raman spectroscopy (SERS) emerged as a
highly sensitive technique for MIP characterization. Xue et al. (2013) combined
FTIR and SERS for the characterization of surface-imprinted core-shell Au NPs for
the selective detection of bisphenol A.
Ultraviolet-visible (UV-Vis) and fluorescence spectroscopies have been used for
recording changes in wavelengths and intensity of absorption bands due to template
recognition. Fan and Wang (2010) monitored by means of UV-Vis spectroscopy the
coordination interactions between the template and a metal in the development of
the selective recognition of a metal coordination imprinted polymer to quercetin.
Zhang et al. (2012) demonstrated the selectivity for the protein template over the
analogues by fluorescence change of MIP-coated quantum dots with template.
Elemental analysis is regularly used to obtain information about the polymer
yield on the surface of a solid support. The elemental composition is essentially carried out by carbon, hydrogen and nitrogen analysis, but in some instances also oxygen and sulfur. A known amount of a substance is converted into simple and known
compounds containing only the element to be quantified. Carbon and hydrogen are
determined by instantaneous oxidation by oxygen combustion of carbon dioxide
and water, while nitrogen-containing compounds are converted into nitrogen gas
(Sellergren and Hall 2001). Regarding microelemental analysis, it is usually performed by energy dispersive X-ray spectroscopy (EDX) or X-ray photoelectron
spectroscopy (XPS), obtaining information about the surface elementary composition and elemental mapping of MIP particles (He et al. 2010). EDX is widely applied
to check the composition of Fe 3 O 4 NPs in order to confirm the synthesis of Fe 3 O 4
NPs (Lahcen et al. 2016). Luo et al. (2014) developed a novel graphene-molecular
imprinted polymer composite to determine electrochemically bovine hemoglobin.
The XPS spectrum, combined with FTIR and SEM, allowed to deduce that a layer
of poly(dopamine) polymer was successfully formed on the graphene surface.
Gel permeation chromatography (GPC), also known as size exclusion chromatography (SEC), is the most commonly used technique for Mw determination
of polymers, which is based on size-exclusion phenomena. This technique provides the M w and the M n and requires calibration with polymers of known Mw,
such as PS standards (Wulff et al. 2006). Similarly, this technique was also used
A. Gómez-Caballero et al.