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Neuromorphic Organic Devices that Specifically Discriminate Dopamine from Its Metabolites by Nonspecific Interactions
Author(s) -
Giordani Martina,
Sensi Matteo,
Berto Marcello,
Di Lauro Michele,
Bortolotti Carlo Augusto,
Gomes Henrique Leonel,
Zoli Michele,
Zerbetto Francesco,
Fadiga Luciano,
Biscarini Fabio
Publication year - 2020
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202002141
Subject(s) - neuromorphic engineering , pedot:pss , materials science , capacitance , electrolyte , dopamine , metabolite , biophysics , chemical physics , nanotechnology , chemistry , electrode , neuroscience , biology , biochemistry , computer science , artificial neural network , layer (electronics) , machine learning
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 amplitude‐depressed 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‐ethylenedioxythiophene):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.