Nanoscale Analysis of a Functionalized Polythiophene Surface by Adhesion Mapping

Synthesis of a conductive polymer thin film having a choline phosphate side group and its bioadhesive properties

A conductive polymer thin film having choline phosphate as the side group was prepared. The polymer thin film can prevent bovine serum albumin binding while present nice fibroblast cell adhesion.

Engineering Antifouling Conducting Polymers for Modern Biomedical Applications

Conducting polymers are considered to be favorable electrode materials for implanted biosensors and bioelectronics, because their mechanical properties are similar to those of biological tissues such as nerve and brain tissues. However, one of the primary challenges for implanted devices is to prevent the unwanted protein adhesion or cell binding within biological fluids. The nonspecific adsorption generally causes the malfunction of implanted devices, which is problematic for long-term applications. When responding to the requirements of solving the problems caused by nonspecific adsorption, an increasing number of studies on antifouling conducting polymers has been recently published. In this review, synthetic strategies for preparing antifouling conducting polymers, including direct synthesis of functional monomers and post-functionalization, are introduced. The applications of antifouling conducting polymers in modern biomedical applications are particularly highlighted. This paper presents focuses on the features of antifouling conducting polymers and the challenges of modern biomedical applications.

Tuning Surface Charge and Morphology for the Efficient Detection of Dopamine under the Interferences of Uric Acid, Ascorbic Acid, and Protein Adsorption

In this research, we aimed to evaluate the impact of the surface charges and morphologies of electrodes on electrochemically detecting dopamine (DA) in the presence of protein adsorption, uric acid (UA), and ascorbic acid (AA). Through the electropolymerization of functionalized 3,4-ethylenedioxythiophenes (EDOT) directly on Au electrodes, we successfully created PEDOT-coated electrodes with three different functional groups and nanostructures. Negatively charged carboxylic acid groups attracted DA while reducing the interferences of UA and AA due to electrostatic effect. We used charge-free tetra(ethylene glycol) and zwitterionic phosphocholine groups are used to evaluate the interference of protein adsorption on DA sensing because they both can effectively prevent the nonspecific adsorption of proteins. These two electrodes can avoid protein adsorption, yet proved ineffective for DA sensing: both tetra(ethylene glycol) and the phosphocholine groups are electroneutral and have minimal electrostatic interactions with DA. We also used three proteins of different isoelectric points - bovine serum albumin, lysozyme, and fibrinogen - to evaluate the influence of protein adsorption on DA detection. We found that for an electrode coated with carboxylic acid-functionalized PEDOT, the adsorption of positively charged lysozyme can promote the detection sensitivity of AA and UA, and that all protein adsorption lowers the sensitivity of DA. In contrast, nanostructures promote the detection sensitivity of all three molecules. All of our tested functionalized PEDOT-coated electrodes demonstrated good stability and functionality in buffers.

Spatially nanoscale-controlled functional surfaces toward efficient bioactive platforms

Interest in well-defined surface architectures has shown a steady increase, particularly among those involved in biological applications where the reactivity of functional groups on the surface is desired to be close to that of the solution phase. Recent research has demonstrated that utilizing the self-assembly process is an attractive and viable choice for the fabrication of two-dimensional nanoscale-controlled architectures. This review highlights representative examples for controlling the spatial placement of reactive functional groups in the optimization of bioactive surfaces. While the selection is not comprehensive, it becomes evident that surface architecture is one of the key components in allowing efficient biomolecular interactions with surfaces and that the optimized lateral spacing between the immobilized molecules is crucial and even critical in some cases.