Electrochemical platform for the detection of adenosine using a sandwich-structured molecularly imprinted polymer-based sensor

An innovative sandwich MIP-based electrochemical sensor was fabricated for the fast and selective detection of adenosine. The covalent-imprinted biomimetic recognition element relies on two overlapping polymeric films, an underlaying composite boronate-affinity and poly(bithiophene)-structural layer and an overlaying poly(3-indolacetic acid) coating bearing carboxyl groups, intended to further shape the selectivity of the sensor towards adenosine. The sensor's behavior and analytical performance was characterized by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). The recorded DPVs showed a linear response to increasing concentration of adenosine in the range of 0.37 mu M-37.4 mu M with a limit of detection of 0.21 mu M. The selectivity of the MIP sensor towards adenosine was demonstrated against more than 10 structurally related interferents. The developed sensor was applied for the fast and quantitative assessment of adenosine in spiked urine samples with good recoveries (102.98%-106.34%), proving at least comparable bioanalytical performances in terms of sensitivity, yet greatly improved in terms of selectivity and analysis time to previously reported sensors. (C) 2020 Elsevier Ltd. All rights reserved.