Modulation of Proteinoid Electrical Spiking Activity with Magnetic Nanoparticles

This study looks at how proteinoid microspheres and their magnetic polystyrene (PS) hybrids behave electrochemically. It also explores their computational abilities. These systems show complex membrane potential dynamics. Pure proteinoids spike without external influence, ranging from 5.39 to 9.81 mV. In contrast, PS-modified variants exhibit sinusoidal oscillations. Their behavior can be described by the equation <i>V</i>(<i>t</i>) = <i>A</i> sin(2π<i>ft</i>) + <i>V</i>_offset, where <i>A</i> is about 1.5 mV and <i>f</i> is around 0.05 Hz. Electrochemical impedance spectroscopy shows key differences in charge transport. The PS-modified systems have better conductivity: |<i>Z</i>|_PS = 7.22 × 10⁴ Ω compared to |<i>Z</i>|_prot = 2.03 × 10⁵ Ω. The systems can perform Boolean logic operations with a 5 mV threshold. They show time-dependent gate behavior, making them suitable for unconventional computing applications. Doping with Fe(NO₃)₃ changes the electrical response. This happens through redox processes where Fe³⁺ gains an electron to become Fe²⁺. As a result, there are greater potential differences and more complex timing behaviors. These findings help us understand proteinoid-based bioelectricity better. They also show how these building blocks can be used in biomolecular computing systems.