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

Abstract

This work describes a novel use for the polymeric film, poly(o-aminophenol) (PAP) that was made respon-sive to a specific protein. This was achieved through templated electropolymerization of aminophenol (AP) in the presence of protein. The procedure involved adsorbing prot ein on the electrode surface and thereafter electroploymerizing the aminophenol. Proteins embedded at the outer surface of the polymeric film were digested by proteinase K and then washed away thereby creating vacant sites. The capacity of the template film to specifically rebind protein was tested with myoglobin (Myo), a cardiac biomarker for ischemia. The films acted as biomimetic artificial antibodies and were produced on a gold (Au) screen printed electrode (SPE), as a step towards disposable sensors to enable point-of-care applications.Raman spectroscopy was used to follow the surface modification of the Au-SPE. The ability of the mate-rial to rebind Myo was measured by electrochemical techniques, namely electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV). The d evices displayed linear responses to Myo in EIS and SWV assays down to 4.0 and 3.5 µg/mL, respectively, with detection limits of 1.5 and 0.8 µg/mL. Good selectivity was observed in the presence of troponin T (TnT) and creatine kinase (CKMB) in SWV assays, and accurate results were obtained in applications to spiked serum. The sensor described in this work is a potential tool for screening Myo in point-of-care due to the simplicity of fabrication, disposability, short time response, low cost, good sensitivit y and selectivity.

Plastic antibody for the electrochemical detection of bacterial surface proteins

“…The selectivity of the sensor was evaluated by EIS measurements using the competitive method [28]. In this case, the time and conditions were set as like the calibration of the sensors, and BSA was chosen to check the interferences as a model protein.…”

“…the target analyte), which upon removal [26][27][28] yields nano/micro cavities of specific size, shape, and/or chemical functionality in a matrix. Such molecularly designed cavities show affinity for the imprinted molecule over other structurally and chemically related compounds.…”

“…Preparation of thin films by this method is very attractive for chemical and biological sensing applications, due to long term stability with respect to pH or temperature changes. Several strategies have been used for the fabrication of MIPs, such as vinyl-based [26] or sol-gel polymerizations [27], that are chemically or physically initiated/sustained (i.e., by electromagnetic radiation or and electrical stimulus) [28]. Any of these may be achieved by surface imprinting (2-D) and bulk imprinting (3-D).…”

“…In this regard, and having in mind that a protein is being targeted, aminophenol would be a good choice. The growth of an electropolymerized aminophenol film is self-limiting, and therefore its thickness may be easily controlled [28]. Furthermore, the presence of amino groups at the imprinting polymeric matrix would attract the target protein by permselectivity during the sensing stage which would presumably contribute to an increased sensitivity and better detection ability.…”

Molecularly imprinted polymers in electro analysis of proteins

“…МИП для анализа миоглобина был получен при полимеризации 2-акрил-амидо-2-метил-1-пропансульфоновой кислоты и 3-аминоэтил метакрилата как заряженных компонентов, и акриламида и N,N-метиленбисакриламида как незаряженных компонентов [42], при электрополимеризации о-аминофенола [43]. Анализ связывания проводили методом квадратно-волновой вольтамперометрии (КВВА) и спектроскопии электрохимического импеданса (СЭХИ).…”