Neuromorphic Organic Devices that Specifically Discriminate Dopamine from Its Metabolites by Nonspecific Interactions

Abstract

Specific detection of dopamine (DA) is achieved with organic neuromorphic devices with no specific recognition function in an electrolyte solution. The response to voltage pulses consists of amplitudedepressed current spiking mimicking the short-term plasticity (STP) of synapses. An equivalent circuit hints that the STP timescale of the device arises from the capacitance and resistance of the poly(3,4-ethylenedioxyth iophene):polystyrenesulfonate (PEDOT:PSS) in series with the electrolyte resistance. Both the capacitance and resistance of PEDOT:PSS change with solution compositions. Dose curves are constructed from the STP timescale for each DA metabolite from pM to mM range of concentrations. The STP response of DA is distinctive from the other metabolites even when differences are by one functional group. Both STP and sensitivity to DA are larger across the patho-physiological range with respect to those to DA metabolites. Density functional theory calculations hint to a stronger hydrogen bond pattern of DA ammonium compared to cationic metabolites. The exponential correlation between STP and the binding energy of DA metabolites interacting with PEDOT:PSS indicates that the slow dynamics of ionic species in and out PEDOT:PSS is the origin of the neuromorphic STP. The sensing framework discriminates differences of nonspecific interactions of few kcal mol −1 , corresponding to one functional group in the molecule.

PEDOT:Tosylate‐Polyamine‐Based Organic Electrochemical Transistors for High‐Performance Bioelectronics

“…In the last years, the use of OECTs for sensing applications has shown enormous progress, achieving the successful detection of a variety of biologically relevant analytes. [39,[54][55][56] However, it has been stated that the pH sensitivity of PEDOT:TOS is rather low, [57,58] which hampers its use in pH-based sensing www.advelectronicmat.de devices. The same has been observed for PEDOT:PSS, as the sulfonate moieties function as the counterion in the complex and, moreover, they show a pK a around 2.…”

Electrochemical Biosensing of Dopamine Neurotransmitter: A Review

“…The trans-conductance curves allowed to obtain a linear calibration plot for ascorbic acid, uric acid and dopamine and to separate the redox waves associated with each compound. Similarly, specific detection of dopamine was achieved with organic neuromorphic devices with no specific recognition function in an electrolyte solution [148]. The response to voltage pulses consisted of amplitude-depressed current spiking mimicking the short-term plasticity of synapses.…”

Interfacing cells with organic transistors: a review ofin vitroandin vivoapplications

“…In addition, starting from the two principal architectures (the standard and the planar), different geometriessuch as for example the already mentioned tubistorand sensing mechanisms have been designed and tested in novel and promising cellular applications, such as neuromorphics, another rising field that is of extreme interest in organic bioelectronics. [92][93][94]…”