Detection of cardiac biomarker proteins using a disposable based on a molecularly imprinted polymer grafted onto graphite

Abstract

A low-cost disposable was developed for rapid detection of the protein biomarker myoglobin (Myo) as a model analyte. A screen printed electrode was modified with a molecularly imprinted material grafted on a graphite support and incorporated in a matrix composed of poly(vinyl chloride) and the plasticizer o-nitrophenyloctyl ether. The proteinimprinted material (PIM) was produced by growing a reticulated polymer around a protein template. This is followed by radical polymerization of 4-styrenesulfonic acid, 2-aminoethyl methacrylate hydrochloride, and ethylene glycol dimethacrylate. The polymeric layer was then covalently bound to the graphitic support, and Myo was added during the imprinting stage to act as a template. Non-imprinted control materials (CM) were also prepared by omitting the Myo template. Morphological and structural analysis of PIM and CM by FTIR, Raman, and SEM/EDC microscopies confirmed the modification of the graphite support. The analytical performance of the SPE was assessed by square wave voltammetry. The average limit of detection is 0.79 μg of Myo per mL, and the slope is −0.193±0.006 μA per decade. The SPE-CM cannot detect such low levels of Myo but gives a linear response at above 7.2 μg·mL −1 , with a slope of −0.719± 0.02 μA per decade. Interference studies with hemoglobin, bovine serum albumin, creatinine, and sodium chloride demonstrated good selectivity for Myo. The method was successfully applied to the determination of Myo urine and is conceived to be a promising tool for screening Myo in point-ofcare patients with ischemia.

Plastic antibodies tailored on quantum dots for an optical detection of myoglobin down to the femtomolar range

“…These allow mild polymerization conditions and biocompatible environment to accommodate the protein upon rebinding. Several technical approaches for Myo imprinting reported include the use of Cryogels 29 , surface imprinting 30 , microcontact imprinting 31 , 32 , charged oriented imprinting 33 , electropolymerization 34 , grafting on silicon 35 or graphite supports 36 or using polymerizable liposomes 37 .…”

Photovoltaics, plasmonics, plastic antibodies and electrochromism combined for a novel generation of self-powered and self-signalled electrochemical biomimetic sensors

“…The typical Nyquist plots obtained under this condition are shown in Figure 3B, and confirm a similar behaviour to that obtained in buffered solutions. The concentration of linear response was the same (0.10 ng/mL-10 µg/mL) and the slope was slightly higher, 0.1048 per decade concentration, than that of the buffer medium, which has been a typical behaviour in these kind of sensing systems (Moreira et al, 2015;Moreira et al, 2018). Most likely, this reflects the higher ionic content of urine samples.…”

Electrochemical sensing of macromolecules based on molecularly imprinted polymers: challenges, successful strategies, and opportunities

“…Currently, several approaches are available to synthesize MIPs in the form of film on the transducer surface, with the possibility for an electrochemical readout of the signal related to the molecular recognition event. The main strategies for MIP film synthesis are as follows: drop-casting or spin- and dip-coating of previously synthesized polymers on the electrode surface [ 94 – 98 ] or of solutions containing template and monomers which are subsequently polymerized in situ [ 30 , 95 ]; use of thiol derivatives to form self-assembled layers with molecular recognition properties on gold surfaces [ 81 , 82 ]; synthesis of films by grafting polymerizable groups and/or initiators onto the support surface [ 99 – 102 ]; electropolymerization of a mixture of electroactive monomers and targets [ 103 ] or, alternatively, electrosynthesis of a polymer film after the immobilization of the target on the electrode surface [ 16 , 37 , 85 ]. …”

“…drop-casting or spin- and dip-coating of previously synthesized polymers on the electrode surface [ 94 – 98 ] or of solutions containing template and monomers which are subsequently polymerized in situ [ 30 , 95 ];…”