2 February 2023 in Advanced Electronic Materials
Advances in organic materials manufacturing have enabled the creation of electronic devices using solution‐processing techniques by employing soluble materials with high conductivity grade. In this exploratory study, the use of micro‐contact for poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) polymer ink deposition as high‐quality structured electrodes for organic field‐effect transistors (OFETs) in top‐contact geometry is demonstrated. The optimized OFET's solution‐processed fabrication is a promising strategy to be realized in the simple, cost‐effective roll‐to‐roll manufacturing processes. The electrical performance of the fabricated devices is comparable to transistors with gold electrodes prepared via vacuum deposition, and even exceeding the values of the charge carriers’ mobilities and featuring lower contact resistance (Rc), due to lower charge‐carrier injection barrier for carbon‐based organic electrodes. An addition of multi‐walled carbon nanotubes to the PEDOT:PSS decreases Rc even further, changing the work function for better energy alignment with semiconductor materials.
30 November 2021 in Journal of the Turkish Chemical Society Section A: Chemistry
Bee venom from honey bees (Apis Mellifera L.) is known to have many pharmacological and biological properties. Melittin, a peptide consisting of 26 amino acids, is known as the main component of bee venom. The study aims to develop a rapid capillary electrophoresis method for separating and quantifying melittin in honeybee venom. Since melittin is a basic peptide, it will adhere to the capillary wall during separation. Two different methods were developed in this study for the capillary electrophoretic separation of melittin. As a first approach, a low pH buffer system was used. For the second approach, the capillary column was coated with a positively charged polymer (PEI). With both methods developed, the migration of melittin in the capillary was achieved by preventing wall adsorption. Melittin migrated in 6 min when the low-pH buffer system was applied, whereas its migration time is longer than 10 min in the PEI-coated capillary column. Thus, a low-pH buffer system was preferred for the analysis of the actual bee-venom sample. 100 mmol L-1 phosphoric acid/sodium dihydrogen phosphate system at pH 1.55 was chosen as separation buffer. As a conclusion, a fast and reliable method was developed for the determination of melittin in honeybee venom. The method was applied to an Anatolian bee venom sample to highlight the melittin amount. The melittin amount was found as 24.5 ± 3.4 g 100 g-1 in the bee venom sample.