Electrochemically synthesized molecularly imprinted polymer of thiophene derivatives for flow-injection analysis determination of adenosine-5'-triphosphate (ATP)

Abstract

Two selective chemosensors for adenosine-5'-triphosphate (ATP) determination featuring molecularly imprinted polymer (MIP) film recognition units were fabricated. For imprinting, three different thiophene derivatives were used as functional monomers. That is, the uracil substituent of bis(2,2'-bithienyl)methane 2 complementarily H-bond paired the adenine moiety of ATP, the boronic acid substituent of thiophene 3 covalently bound vicinal diols of the ribofuranose moiety, and amide substituents of bis(2,2'-bithienyl)methanes 4 bound to the pyrophosphate moieties. Different binding motifs adopted for the ATP recognition and the structure of the supramolecular pre-polymerization complex were optimized with the DFT computing at the B3LYP/3-21G((*)) level. MIP films were prepared by potentiodynamic electropolymerization of this complex with the imprinting factor of 9.47±0.2. An analytical signal was transduced with a 10-MHz resonator of EQCM and a Pt electrode for the piezoelectric microgravimetry (PM) and capacitive impedometry (CI) determination of ATP, respectively, under FIA conditions. Analytical properties of the MIP film were unraveled by spectroscopic ellipsometry, XPS, IRRAS, and DPV. The limit of detection was 0.1 and 0.2 μM for the PM and CI chemosensor, respectively, being an order of magnitude lower than the ATP concentration in biological systems. Moreover, cross-selectivity was demonstrated with the adenosine-5'-diphosphate (ADP) imprinting and ATP discrimination.