Preparation of Ultrathin and Degradable Polymeric Films by Electropolymerization of 3-Amino-L-Tyrosine

Bioderived polymers are one of many current areas of research that promise a sustainable future. Due to its unique properties, the bioderived polymer polydopamine (PDA) has been in the spotlight over the last decades. Its ability to adhere to virtually any surface, its stability over a wide pH range was well as in several organic solvents makes it a suitable candidate for various applications like coatings and biosensors. However, strong light absorption over a broad range of wavelengths and the high quenching efficiency limit its uses. Therefore, new bioderived polymers with similar features to PDA but without fluorescence quenching properties are highly desirable. Here, the electropolymerization of a bioderived analogue of dopamine, 3-amino-l-tyrosine (ALT), is demonstrated. The resulting polymer, poly(amino-l-tyrosine) (PALT), exhibits several characteristics complementary to or even exceeding those of PDA and its analog, polynorepinephrine (PNE), rendering PALT attractive for the development of sensors and photoactive devices. Cyclic voltammetry, spectroelectrochemistry, and electrochemical quartz crystal microbalance measurements are applied to study the electrodeposition of this material and the resulting films are compared to PDA and PNE. Impedance spectroscopy reveals increased ion permeability of PALT in comparison to PDA and PNE. Moreover, the reduced fluorescence quenching of PALT supports its use as coating for biosensors and organic semiconductors.Bioderived polymers are one of many current areas of research that promise a sustainable future. Due to its unique properties, the bioderived polymer polydopamine (PDA) has been in the spotlight over the last decades. Its ability to adhere to virtually any surface, its stability over a wide pH range was well as in several organic solvents makes it a suitable candidate for various applications like coatings and biosensors. However, strong light absorption over a broad range of wavelengths and the high quenching efficiency limit its uses. Therefore, new bioderived polymers with similar features to PDA but without fluorescence quenching properties are highly desirable. Here, the electropolymerization of a bioderived analogue of dopamine, 3-amino-l-tyrosine (ALT), is demonstrated. The resulting polymer, poly(amino-l-tyrosine) (PALT), exhibits several characteristics complementary to or even exceeding those of PDA and its analog, polynorepinephrine (PNE), rendering PALT attractive for the development of sensors and photoactive devices. Cyclic voltammetry, spectroelectrochemistry, and electrochemical quartz crystal microbalance measurements are applied to study the electrodeposition of this material and the resulting films are compared to PDA and PNE. Impedance spectroscopy reveals increased ion permeability of PALT in comparison to PDA and PNE. Moreover, the reduced fluorescence quenching of PALT supports its use as coating for biosensors and organic semiconductors.