Electrosynthesis of polydopamine-ethanolamine films for the development of immunosensing interfaces

Abstract

We report a straightforward and reproducible electrochemical approach to develop polydopamine-ethanolamine (ePDA-ETA) films to be used as immunosensing interfaces. ETA is strongly attached to polydopamine films during the potentiodynamic electropolymerization of dopamine. The great advantage of the electrochemical methods is to generate the oxidized species (quinones), which can readily react with ETA amine groups present in solution, with the subsequent incorporation of this molecule in the polymer. The presence of ETA and its effect on the electrosynthesis of polydopamine was accessed by cyclic voltammetry, ellipsometry, atomic force microscopy, FTIR and X-ray photoelectron spectroscopy. The adhesive and biocompatible films enable a facile protein linkage, are resilient to flow assays, and display intrinsic anti-fouling properties to block non-specific protein interactions, as monitored by real-time surface plasmon resonance, and confirmed by ellipsometry. Immunoglobulin G (IgG) and Anti-IgG were used in this work as model proteins for the affinity sensor. By using the one-step methodology (ePDA-ETA), the lower amount of immobilized biorecognition element, IgG, compared to that deposited on ePDA or on ETA post-modified film (ePDA/ETA), allied to the presence of ETA, improved the antibody-antigen affinity interaction. The great potential of the developed platform is its versatility to be used with any target biorecognition molecules, allowing both optical and electrochemical detection.

A comparative study of the oxidation of dopamine in deep eutectic solvents: A potential approach to synthesis polydopamine particles with various shapes, sizes, and compositions

“…26a, 27 The moderate absorption bands at 1628 and 1274 cm À1 were attributed to the stretching vibrations of C═C and aromatic C N, respectively. 27,28 These results further implied that dopamine polymerization in ChCl/EG (in the presence of CS) did not follow the oxidative cyclization pathway (path b in Scheme S1). Although this pathway will be discussed in more details in the following sections, it is necessary to briefly mention the main indications of it.…”

“…27 The presence of such structures could be further confirmed by the absorption bands at 1628 and 1478 cm À1 which could be referred to the skeletal C═C stretching vibration of the aromatic ring. 27,28 The -NH 2 scissoring vibration mode may also have contribution to the observed absorption bands in the region of 1600-1400 cm À1 . 28 The synthesized PDA particles at 1:3 dopamine/CS ratio showed a fewer number of distinct IR absorption bands which could be connected to their more rigid structures.…”

“…27,28 The -NH 2 scissoring vibration mode may also have contribution to the observed absorption bands in the region of 1600-1400 cm À1 . 28 The synthesized PDA particles at 1:3 dopamine/CS ratio showed a fewer number of distinct IR absorption bands which could be connected to their more rigid structures. 29 The broad band at $3400 cm À1 might be the overlapping peak of H-bonded O H and aromatic N H stretches.…”

A flexible IrO2 membrane for pH sensing

“…3 b, exhibited stronger intensities for both C–O/C–N and C = O bonds, as well as moderate presence of carboxyl (O–C = O) bond. Since the PDA contains phenol, amine, and ketone groups in its chemical structure, and the PVA is synthesized by partial or fully hydrolysis of polyvinyl acetate, the coexistence of O–C = O, C–O, C = O, and C–N was reasonably expected 23 , 24 . Figure 3 c,d display the N1s profiles for PPMM and PPMM@PDA/PVA(1/8), respectively.…”

Biochemistry strategies for label-free optical sensor biofunctionalization: advances towards real applicability

“…Besides PEG/OEG and zwitterionic compounds, other polymers have also been studied as antifouling scaffolds for biosensors such as polydopamine (pDOPA) [69][70][71], polyacrylamide [72] or poly-(hydroxyethyl methacrylate) brushes (pHEMA) [73], or the more recently proposed, poly(β-peptoid)s [74,75]. Peptoids are structural isomers of peptides that differ in the linking position of the functional sidechains, which are located in the α-nitrogen instead of the α-carbon of the backbone.…”