Myoglobin-biomimetic electroactive materials made by surface molecular imprinting on silica beads and their use as ionophores in polymeric membranes for potentiometric transduction

Abstract

Myoglobin (Mb) is among the cardiac biomarkers playing a major role in urgent diagnosis of cardio-vascular diseases. Its monitoring in point-ofcare is therefore fundamental. Pursuing this goal, a novel biomimetic ionophore for the potentiometric transduction of Mb is presented. It was synthesized by surface molecular imprinting (SMI) with the purpose of developing highly efficient sensor layers for near-stereochemical recognition of Mb. The template (Mb) was imprinted on a silane surface that was covalently attached to silica beads by means of self-assembled monolayers. First the silica was modified with an external layer of aldehyde groups. Then, Mb was attached by reaction with its amine groups (on the external surface) and subsequent formation of imine bonds. The vacant places surrounding Mb were filled by polymerization of the silane monomers 3-aminopropyltrimethoxysilane (APTMS) and propy-ltrimethoxysilane (PTMS). Finally, the template was removed by imine cleavage after treatment with oxalic acid. The results materials were finely dispersed in plasticized PVC selective membranes and used as ionophores in potentiometric transduction. The best analytical features were found in HEPES buffer of pH 4. Under this condition, the limits of detection were of 1.3 × 10 −6 mol/L for a linear response after 8.0 × 10 −7 mol/L with an anionic slope of −65.9 mV/decade. The imprinting effect was tested by prepar-ing non-imprinted (NI) particles and employing these materials as ionophores. The resulting membranes showed no ability to detect Mb. Good selectivity was observed towards creatinine, sacarose, fructose, galactose, sodium glutamate, and alanine. The analytical application was conducted successfully and showed accurate and precise results.

Electrochemical biosensor based on biomimetic material for myoglobin detection

“…These were first from natural origin but the advances of nanotechnology have come up with many synthetic versions of these elements [5][6][7].…”

“…So far, different strategies for Myo detection and quantification based on surface imprinting were described in the literature, including sol-gel methods merged with self assembling monolayer for potentiometric transduction [6,22], silicon surface grafting [13] and thin film/micro contact imprinting mass with spectrometrybased profiling system [23], none of these coupling these two simple concepts of MIP receptors and SPE technology. Several techniques have been described in the literature for Myo quantification [24][25][26][27][28].…”

Protein-responsive polymers for point-of-care detection of cardiac biomarker

“…The present biosensor does not have a better analytical performance than most of the previous devices employing molecular imprinting procedures [67,68,28,25]. However, its response is among the range of concentration of clinical significance and the device set-up is by far the quicker, the simplest and the cheaper process presented so far.…”

“…Few strategies of protein surface imprinting in cardiac biomarker sensing context have been employed so far [23][24][25][26][27][28][29], involving surface imprinting procedures on gold [24,[28][29][30], silica [25,26], or carbon [27], while employing different approaches for assembling the polymeric network. Among these, electropolymerization seems to be the simplest approach towards protein imprinting that seems to have been developed first by Panasyuk et al for a small target analyte [31], and applied later to proteins by Cai et al [32].…”

Immunosensing with artificial antibodies in organic solvents or complex matrices

“…To address this problem, surface imprinting was developed [20]. Using imprinted nanoparticles is one approach to increase the surface area of the imprinted polymer [21][22][23]. Recently, methods for double imprinting were developed to transfer the selectiv-ity of natural antibodies or enzymes to a polymer [24][25][26][27] (see Fig.…”